In this monograph I present my experience with the extremely halotolerant ciliate Fabrea salina. It is an organism able to be kept or cultured in the laboratory under a wide range of salinities (from normal to >200 ppt). It can grow filtering all kinds of microalgae and reach high desnsities (>100 ind./ml). It can serve as live food in marine fish hatcheries.
This document discusses the habitat, cellular structure, and characteristics of several genera of cyanobacteria including Nostoc, Anabaena, Aphanizomenon, Cylindrospermum, Cylindrospermopsis, Tolypothrix, Scytonema, Gloeotrichia, and Stigonema. Nostoc is found in terrestrial habitats like moist rocks and alkaline soil and contributes to fertilization in rice paddies. Anabaena forms filaments of spherical cells in freshwater and the Baltic Sea. Aphanizomenon forms large visible aggregations in the Baltic Sea and eutrophic inland waters. Cylindrospermum is found in soft, acid freshwater lakes
Ultrastructure of fungal cell and different type ofjeeva raj
This document is a seminar report submitted by Jeeva Raj Joseph on the ultrastructure of fungal cells and different types of spores. It discusses the key components of the fungal cell, including the cell wall, plasma membrane, cytoplasm, organelles, and inclusions. It describes the different types of septa that can divide fungal hyphae. The report also examines the two main types of asexual spores - sporangiospores and conidia - and provides details on different subtypes like arthrospores, blastospores, and phialospores. Finally, it briefly discusses sexually produced spores and how certain spore types are characteristic of different fungal taxa.
The document discusses various types of algae, including cyanobacteria, euglena, dinoflagellates, cryptomonads, and chrysophytes. It provides details on their characteristics, evolution, importance, reproduction, anatomy, locomotion, and classification. Cyanobacteria were among the first organisms to produce oxygen through photosynthesis, helping create the Earth's oxidizing atmosphere. Dinoflagellates are mainly marine plankton that can cause red tides that kill fish. Chrysophytes were once thought to be cyanobacteria but fossil evidence shows they evolved separately.
Observations on the Life History of the Brazilian Frog Oocormus micropsMuseu-Bertha
1) The author observed the development of a clutch of 30 eggs of the frog Oocormus microps from the time they were discovered until well after metamorphosis.
2) The non-aquatic tadpoles hatched with a large yolk sac and direct developing limbs, indicating terrestrial development. The entire larval stage lasted only 17 days.
3) Characteristics like eye coloration and lack of an external ear confirmed the eggs belonged to O. microps. The tadpoles remained in the nest where the eggs were laid.
This document provides an overview of key features of the ascomycota phylum. It describes their cell walls, hyphae, ability to fuse, and occurrence of dikaryotic cells. It then discusses important aspects of their life cycle including the meiosporangia or ascus, teleomorph and anamorph stages, and types of ascomata. It also details the different types of asci and ascospores as well as methods of asexual reproduction.
This document describes the cyanobacterium Anabaena. Key points:
- Anabaena is a filamentous, nitrogen-fixing cyanobacterium that can form symbiotic relationships with plants. It reproduces asexually through fragmentation, hormogones, and akinetes.
- It has specialized cells called heterocysts that facilitate nitrogen fixation. Akinetes are thick-walled dormant cells that allow survival in unfavorable conditions.
- Anabaena plays an important ecological role in nutrient cycling and has significance in agriculture through symbiotic relationships like with azolla that fertilize rice paddies.
This document discusses the habitat, cellular structure, and characteristics of several genera of cyanobacteria including Nostoc, Anabaena, Aphanizomenon, Cylindrospermum, Cylindrospermopsis, Tolypothrix, Scytonema, Gloeotrichia, and Stigonema. Nostoc is found in terrestrial habitats like moist rocks and alkaline soil and contributes to fertilization in rice paddies. Anabaena forms filaments of spherical cells in freshwater and the Baltic Sea. Aphanizomenon forms large visible aggregations in the Baltic Sea and eutrophic inland waters. Cylindrospermum is found in soft, acid freshwater lakes
Ultrastructure of fungal cell and different type ofjeeva raj
This document is a seminar report submitted by Jeeva Raj Joseph on the ultrastructure of fungal cells and different types of spores. It discusses the key components of the fungal cell, including the cell wall, plasma membrane, cytoplasm, organelles, and inclusions. It describes the different types of septa that can divide fungal hyphae. The report also examines the two main types of asexual spores - sporangiospores and conidia - and provides details on different subtypes like arthrospores, blastospores, and phialospores. Finally, it briefly discusses sexually produced spores and how certain spore types are characteristic of different fungal taxa.
The document discusses various types of algae, including cyanobacteria, euglena, dinoflagellates, cryptomonads, and chrysophytes. It provides details on their characteristics, evolution, importance, reproduction, anatomy, locomotion, and classification. Cyanobacteria were among the first organisms to produce oxygen through photosynthesis, helping create the Earth's oxidizing atmosphere. Dinoflagellates are mainly marine plankton that can cause red tides that kill fish. Chrysophytes were once thought to be cyanobacteria but fossil evidence shows they evolved separately.
Observations on the Life History of the Brazilian Frog Oocormus micropsMuseu-Bertha
1) The author observed the development of a clutch of 30 eggs of the frog Oocormus microps from the time they were discovered until well after metamorphosis.
2) The non-aquatic tadpoles hatched with a large yolk sac and direct developing limbs, indicating terrestrial development. The entire larval stage lasted only 17 days.
3) Characteristics like eye coloration and lack of an external ear confirmed the eggs belonged to O. microps. The tadpoles remained in the nest where the eggs were laid.
This document provides an overview of key features of the ascomycota phylum. It describes their cell walls, hyphae, ability to fuse, and occurrence of dikaryotic cells. It then discusses important aspects of their life cycle including the meiosporangia or ascus, teleomorph and anamorph stages, and types of ascomata. It also details the different types of asci and ascospores as well as methods of asexual reproduction.
This document describes the cyanobacterium Anabaena. Key points:
- Anabaena is a filamentous, nitrogen-fixing cyanobacterium that can form symbiotic relationships with plants. It reproduces asexually through fragmentation, hormogones, and akinetes.
- It has specialized cells called heterocysts that facilitate nitrogen fixation. Akinetes are thick-walled dormant cells that allow survival in unfavorable conditions.
- Anabaena plays an important ecological role in nutrient cycling and has significance in agriculture through symbiotic relationships like with azolla that fertilize rice paddies.
Actinomycetes are filamentous, gram-positive bacteria that have characteristics of both bacteria and fungi. They form a mycelium like fungi but have bacterial cell walls lacking chitin and cellulose. Common genera found in soil include Streptomyces, Nocardia, and Micromonospora. Streptomyces and Nocardia are important because they produce many antibiotics and can cause infections in humans. Nocardia forms branching filaments and causes pneumonia and brain infections, especially in immunocompromised individuals.
1. The document discusses various aspects of fungal genetics including the life cycles, modes of reproduction, and nuclear states of fungi.
2. It notes that fungi typically have haploid vegetative states and undergo plasmogamy and karyogamy during sexual reproduction, followed immediately by meiosis.
3. The document also discusses asexual reproduction in fungi through spores, as well as parasexual reproduction which involves nuclear fusion without meiosis.
There are three main types of reproduction in algae: vegetative, asexual and sexual. Vegetative reproduction occurs through fragmentation, cell division or the formation of specialized structures like hormogones, tubers or adventitious branches. Asexual reproduction happens through the formation of spores like zoospores, aplanospores or autospores which develop into new algae. Sexual reproduction includes isogamy, anisogamy and oogamy where gametes fuse to form zygotes or oospores that develop into new organisms. Sexual reproduction provides benefits like increasing genetic diversity and adaptation to changing environments.
This document provides an overview of the kingdom Protista, which includes mostly single-celled eukaryotic organisms. It discusses the diversity of protists, including their habitats, modes of nutrition, and life cycles. It then describes several examples of protist groups in more detail, including Euglenozoa (euglenoids and kinetoplastids), Alveolata (dinoflagellates, ciliates, apicomplexans), Stramenopiles (brown algae, diatoms), and Rhodophyta (red algae). It highlights the importance of protists and their role in ecosystems.
The presentation covers all the basic aspects of Kingdom Fungi including its salient features, cell wall structure, nutrition, spore forms, and reproduction.
This document discusses fungi that have septate hyphae and a dikaryophase, specifically the phyla Ascomycota and Basidiomycota. It provides details on the characteristics and life cycles of ascomycetes, including their sexual and asexual reproduction and the structures involved. It describes the traditional system of classifying ascomycetes based on characteristics of their ascomata, and notes that this system is artificial and does not reflect phylogenetic relationships.
This document summarizes key aspects of protists, including their taxonomy, characteristics, Lynn Margulis' endosymbiont hypothesis of their evolution from prokaryotes, and descriptions of major protist phyla including animal-like protists (Ciliophora, Ameba) and plant-like protists (Euglenophyta, Pyrrophyta, slime molds). It notes the challenges of classifying unicellular eukaryotes before the kingdom Protista was established.
This document summarizes key concepts about protists from Chapter 17:
- Protists are a diverse group of eukaryotic organisms that may represent the oldest eukaryotes. They vary greatly in size, nutrition, and habitat.
- Protists include protozoans like amoebas, flagellates, and ciliates that move using pseudopods, flagella, or cilia. They also include algae, slime molds, and parasitic sporozoans.
- Algae like diatoms, dinoflagellates, red algae, brown algae, and green algae are important primary producers in aquatic ecosystems and sources of food and oxygen. Some are
Activity 2 - Determination of Bacterial MotilityAngelica Bade
This document describes experiments to determine the motility of various microorganisms. Wet mount and hanging drop techniques were used to observe motility. Brownian motion, exhibited by Saccharomyces cerevisiae, is random movement caused by water molecule bombardment, while true motility involves self-propulsion using flagella or cilia. Proteus vulgaris showed motility in culture, while Staphylococcus aureus, Saccharomyces cerevisiae, and Micrococcus luteus were non-motile. The experiments allowed identification of motile versus non-motile microbes and differentiation of Brownian motion from true self-propelled motility.
This document provides information about yeast. It defines yeast as a microscopic fungi that can convert sugar into alcohol and carbohydrates. Yeast is used to produce various foods through fermentation like bread, beer, wine, vinegar and cheese. The document describes the morphology of yeast cells as single-celled fungi ranging from 1-5um wide and 5-30um long without flagella. It reproduces asexually through budding or fission and sexually through various life cycles. Physiologically, yeast grows best with moisture and sugars as an energy source.
Actinomycetes are a group of Gram-positive, filamentous bacteria that resemble fungi in some ways. They include the genera Actinomyces, Nocardia, and Streptomyces. Actinomycetes are commonly found in soil where they aid in decomposition. Many produce important antibiotics like streptomycin. While usually saprophytic, some Actinomycetes can cause disease in humans or animals through inhalation or direct inoculation, often taking advantage of breaks in mucous membranes to infect normally sterile tissues.
This document provides information about the cyanobacteria Oscillatoria. It discusses its systematic position as a genus in the order Oscillatoriales, describes its occurrence in moist places with decaying organic matter, and details its plant body structure as unbranched trichomes of cylindrical cells contained in a thin sheath. Reproduction is solely vegetative, occurring through the formation of harmogonia fragments or accidental trichome breakage. Oscillatoria has economic importance for soil reclamation, pollution indication, oxygen production, symbiotic associations, protein content, and nitrogen fixation.
General properties of fungi, algae & protozaAmjad Afridi
This document summarizes the general properties of fungi, algae, and protozoa. It describes that fungi are eukaryotic, multicellular organisms that lack chlorophyll and reproduce both sexually and asexually. Algae are also eukaryotic but are photosynthetic and can range in size from microscopic to 50 meters long. They reproduce sexually and asexually. Protozoa are unicellular eukaryotes that can move using flagella, cilia, or pseudopodia, and reproduce through binary fission or budding. The document outlines examples of diseases caused by each group and their economic and environmental impacts.
Vegetative reproduction in algae can occur through fragmentation, the formation of adventitious branches, bulbils, or hormogonia. Algae also reproduce asexually through spores like zoospores, aplanospores, tetraspores, akinetes, exospores, and endospores. Sexual reproduction involves the fusion of gametes, which can be isogamous (similar gametes), anisogamous (different sized gametes), or oogamous (egg and sperm). Zygotes form after gamete fusion and develop into new algae.
Oomycetes, commonly known as water molds, are eukaryotic organisms that are closely related to algae. They include some of the most devastating plant pathogens, causing diseases like late blight of potato and downy mildew of grapevines. Oomycetes reproduce both sexually, through the formation of gametangia and fertilization leading to thick-walled oospores, and asexually via motile zoospores or non-motile sporangia. While they were long classified as fungi, genetic evidence shows they are more closely related to algae and plants. Key differences from true fungi include having cell walls composed of cellulose and lacking chitin.
Micro-organisms play an important role in our daily lives. The document discusses the key characteristics of three important micro-organisms: bacteria, fungi, and Rhizopus mold. Bacteria are unicellular, come in different shapes, and are vital to nutrient cycles. Fungi are eukaryotic, obtain food through decomposition or parasitism, and their filamentous structure is called mycelium. Rhizopus mold is a type of bread mold that reproduces both sexually through conjugation of hyphae and asexually through spores.
The document discusses the classification of fungi. It outlines the major criteria used to classify fungi, including morphology, anatomy, nutrition, physiology, and molecular methods. Fungi are more closely related to animals than plants. There are currently three main fungal kingdoms: Protista, Chromista, and Eumycota. Eumycota is further divided into several phyla including Chytridiomycota, Zygomycota, Ascomycota, Basidiomycota, and formerly Deuteromycota. The document provides details on the characteristics and examples of fungi within each phylum.
This document discusses the kingdom Straminipila and the phylum Oomycota. It describes the key characteristics of Straminipila including having cell walls made of cellulose and glucan. It outlines the life cycle of Oomycota, which have motile zoospores and reproduce sexually through oogamous fertilization. The document also examines several important genera of Oomycota like Pythium, which can cause diseases in plants, and Phytophthora, which are destructive plant pathogens.
La botánica (del griego βοτάνη, 'hierba') o fitología (del griego φυτόν, 'planta' y λόγος, 'tratado') es la rama de la biología que estudia las plantas bajo todos sus aspectos, incluyendo la descripción, clasificación, distribución, identificación, estudio de la reproducción, fisiología, morfología, relaciones recíprocas, relaciones con los otros seres vivos y efectos provocados sobre el medio en el que se encuentran.
Actinomycetes are filamentous, gram-positive bacteria that have characteristics of both bacteria and fungi. They form a mycelium like fungi but have bacterial cell walls lacking chitin and cellulose. Common genera found in soil include Streptomyces, Nocardia, and Micromonospora. Streptomyces and Nocardia are important because they produce many antibiotics and can cause infections in humans. Nocardia forms branching filaments and causes pneumonia and brain infections, especially in immunocompromised individuals.
1. The document discusses various aspects of fungal genetics including the life cycles, modes of reproduction, and nuclear states of fungi.
2. It notes that fungi typically have haploid vegetative states and undergo plasmogamy and karyogamy during sexual reproduction, followed immediately by meiosis.
3. The document also discusses asexual reproduction in fungi through spores, as well as parasexual reproduction which involves nuclear fusion without meiosis.
There are three main types of reproduction in algae: vegetative, asexual and sexual. Vegetative reproduction occurs through fragmentation, cell division or the formation of specialized structures like hormogones, tubers or adventitious branches. Asexual reproduction happens through the formation of spores like zoospores, aplanospores or autospores which develop into new algae. Sexual reproduction includes isogamy, anisogamy and oogamy where gametes fuse to form zygotes or oospores that develop into new organisms. Sexual reproduction provides benefits like increasing genetic diversity and adaptation to changing environments.
This document provides an overview of the kingdom Protista, which includes mostly single-celled eukaryotic organisms. It discusses the diversity of protists, including their habitats, modes of nutrition, and life cycles. It then describes several examples of protist groups in more detail, including Euglenozoa (euglenoids and kinetoplastids), Alveolata (dinoflagellates, ciliates, apicomplexans), Stramenopiles (brown algae, diatoms), and Rhodophyta (red algae). It highlights the importance of protists and their role in ecosystems.
The presentation covers all the basic aspects of Kingdom Fungi including its salient features, cell wall structure, nutrition, spore forms, and reproduction.
This document discusses fungi that have septate hyphae and a dikaryophase, specifically the phyla Ascomycota and Basidiomycota. It provides details on the characteristics and life cycles of ascomycetes, including their sexual and asexual reproduction and the structures involved. It describes the traditional system of classifying ascomycetes based on characteristics of their ascomata, and notes that this system is artificial and does not reflect phylogenetic relationships.
This document summarizes key aspects of protists, including their taxonomy, characteristics, Lynn Margulis' endosymbiont hypothesis of their evolution from prokaryotes, and descriptions of major protist phyla including animal-like protists (Ciliophora, Ameba) and plant-like protists (Euglenophyta, Pyrrophyta, slime molds). It notes the challenges of classifying unicellular eukaryotes before the kingdom Protista was established.
This document summarizes key concepts about protists from Chapter 17:
- Protists are a diverse group of eukaryotic organisms that may represent the oldest eukaryotes. They vary greatly in size, nutrition, and habitat.
- Protists include protozoans like amoebas, flagellates, and ciliates that move using pseudopods, flagella, or cilia. They also include algae, slime molds, and parasitic sporozoans.
- Algae like diatoms, dinoflagellates, red algae, brown algae, and green algae are important primary producers in aquatic ecosystems and sources of food and oxygen. Some are
Activity 2 - Determination of Bacterial MotilityAngelica Bade
This document describes experiments to determine the motility of various microorganisms. Wet mount and hanging drop techniques were used to observe motility. Brownian motion, exhibited by Saccharomyces cerevisiae, is random movement caused by water molecule bombardment, while true motility involves self-propulsion using flagella or cilia. Proteus vulgaris showed motility in culture, while Staphylococcus aureus, Saccharomyces cerevisiae, and Micrococcus luteus were non-motile. The experiments allowed identification of motile versus non-motile microbes and differentiation of Brownian motion from true self-propelled motility.
This document provides information about yeast. It defines yeast as a microscopic fungi that can convert sugar into alcohol and carbohydrates. Yeast is used to produce various foods through fermentation like bread, beer, wine, vinegar and cheese. The document describes the morphology of yeast cells as single-celled fungi ranging from 1-5um wide and 5-30um long without flagella. It reproduces asexually through budding or fission and sexually through various life cycles. Physiologically, yeast grows best with moisture and sugars as an energy source.
Actinomycetes are a group of Gram-positive, filamentous bacteria that resemble fungi in some ways. They include the genera Actinomyces, Nocardia, and Streptomyces. Actinomycetes are commonly found in soil where they aid in decomposition. Many produce important antibiotics like streptomycin. While usually saprophytic, some Actinomycetes can cause disease in humans or animals through inhalation or direct inoculation, often taking advantage of breaks in mucous membranes to infect normally sterile tissues.
This document provides information about the cyanobacteria Oscillatoria. It discusses its systematic position as a genus in the order Oscillatoriales, describes its occurrence in moist places with decaying organic matter, and details its plant body structure as unbranched trichomes of cylindrical cells contained in a thin sheath. Reproduction is solely vegetative, occurring through the formation of harmogonia fragments or accidental trichome breakage. Oscillatoria has economic importance for soil reclamation, pollution indication, oxygen production, symbiotic associations, protein content, and nitrogen fixation.
General properties of fungi, algae & protozaAmjad Afridi
This document summarizes the general properties of fungi, algae, and protozoa. It describes that fungi are eukaryotic, multicellular organisms that lack chlorophyll and reproduce both sexually and asexually. Algae are also eukaryotic but are photosynthetic and can range in size from microscopic to 50 meters long. They reproduce sexually and asexually. Protozoa are unicellular eukaryotes that can move using flagella, cilia, or pseudopodia, and reproduce through binary fission or budding. The document outlines examples of diseases caused by each group and their economic and environmental impacts.
Vegetative reproduction in algae can occur through fragmentation, the formation of adventitious branches, bulbils, or hormogonia. Algae also reproduce asexually through spores like zoospores, aplanospores, tetraspores, akinetes, exospores, and endospores. Sexual reproduction involves the fusion of gametes, which can be isogamous (similar gametes), anisogamous (different sized gametes), or oogamous (egg and sperm). Zygotes form after gamete fusion and develop into new algae.
Oomycetes, commonly known as water molds, are eukaryotic organisms that are closely related to algae. They include some of the most devastating plant pathogens, causing diseases like late blight of potato and downy mildew of grapevines. Oomycetes reproduce both sexually, through the formation of gametangia and fertilization leading to thick-walled oospores, and asexually via motile zoospores or non-motile sporangia. While they were long classified as fungi, genetic evidence shows they are more closely related to algae and plants. Key differences from true fungi include having cell walls composed of cellulose and lacking chitin.
Micro-organisms play an important role in our daily lives. The document discusses the key characteristics of three important micro-organisms: bacteria, fungi, and Rhizopus mold. Bacteria are unicellular, come in different shapes, and are vital to nutrient cycles. Fungi are eukaryotic, obtain food through decomposition or parasitism, and their filamentous structure is called mycelium. Rhizopus mold is a type of bread mold that reproduces both sexually through conjugation of hyphae and asexually through spores.
The document discusses the classification of fungi. It outlines the major criteria used to classify fungi, including morphology, anatomy, nutrition, physiology, and molecular methods. Fungi are more closely related to animals than plants. There are currently three main fungal kingdoms: Protista, Chromista, and Eumycota. Eumycota is further divided into several phyla including Chytridiomycota, Zygomycota, Ascomycota, Basidiomycota, and formerly Deuteromycota. The document provides details on the characteristics and examples of fungi within each phylum.
This document discusses the kingdom Straminipila and the phylum Oomycota. It describes the key characteristics of Straminipila including having cell walls made of cellulose and glucan. It outlines the life cycle of Oomycota, which have motile zoospores and reproduce sexually through oogamous fertilization. The document also examines several important genera of Oomycota like Pythium, which can cause diseases in plants, and Phytophthora, which are destructive plant pathogens.
La botánica (del griego βοτάνη, 'hierba') o fitología (del griego φυτόν, 'planta' y λόγος, 'tratado') es la rama de la biología que estudia las plantas bajo todos sus aspectos, incluyendo la descripción, clasificación, distribución, identificación, estudio de la reproducción, fisiología, morfología, relaciones recíprocas, relaciones con los otros seres vivos y efectos provocados sobre el medio en el que se encuentran.
Introduction of algae and general characteristics
Fossil history of algae
Endosymbiosis Theory
Where are algae abound? Ecology
Algal Blooms
Eutrophication
How are algae similar to higher plants?
How are algae different from higher plants?
Variations in the pigment constitution
Prokaryotic vs eukaryotic algae...............
Presentation
BEST OF LUCK
This document provides information on stomatal physiology in plants. It discusses the structure and characteristics of stomata, including that stomata are minute pores consisting of two guard cells and located on plant leaves and stems. It describes how the number and distribution of stomata varies between plant species and types. The document also examines various theories of stomatal movement, explaining that stomata typically open in the presence of light via potassium ion influx and close in darkness due to acidification and abscisic acid signaling. In summary, the document outlines the key components and functions of stomata, the structures responsible for gas exchange in plant leaves and aerial tissues.
This document describes 15 genera of diatoms: Coscinodiscus, Ditylum, Eucampia, Guinardia, Leptocylindrus, Pleurosigma, Rhizosolenia, Skeletonema, Stephanopyxis, Thalassionema, Thalassiosira, Thalassiothrix, Chaetoceros, Bacteriastrum, and Asteromphalus. For each genus it provides the classification, description, cell size, and distribution. The genera described represent common marine planktonic diatoms found worldwide.
The document discusses various protozoan parasites that can infect shellfish, including Vorticella, Epistylis, Zoothamnium, Acineta, and Ephelota. It describes the appearance and effects of each protozoan, as well as symptoms they can cause like fuzzy growths on shells and gills. Maintaining good water quality and avoiding stressors can help prevent protozoan infections in shellfish farms.
The document summarizes several species of unusually large prokaryotes. Thiomargarita namibiensis is a spherical sulfur-oxidizing bacterium that can reach 750 μm in diameter, making it one of the largest known single-celled organisms. It stores sulfur globules and other inclusions, leaving only 2% of its volume as active cytoplasm. Beggiatoa are filamentous bacteria that form white mats and can reach lengths of 160 μm. Thioploca araucae live as bundles of 15-40 μm thick filaments in a common sheath in marine sediments. Epulopiscium fishelsoni is a gut symbiont of fish that can reach lengths of 200
The document is an assignment submitted by a student for a Plant Diversity course. It contains 3 questions about algae morphology, anatomy, and life cycles. In response to the first question, the student describes the four major morphological forms of algae as unicellular, filamentous, colonial, or thallose. The student also discusses the diversity of photosynthetic pigments and other distinguishing characteristics among the five major algal divisions.
This document provides an introduction and overview of gram-negative bacteria. It discusses their key characteristics and classification. Specifically, it summarizes several genera of gram-negative bacteria, including Pseudomonas, Xanthomonas, Azotobacter, Rhizobium, Methylococcus, Acetobacter, and Legionella. It also describes the families they belong to, such as Pseudomonadaceae, Azotobacteraceae, and Legionellaceae.
1. Anthoceros is a genus of hornworts that reproduces both vegetatively and sexually. It has a thallus-like structure and reproduces vegetatively through fragmentation, gemmae, tubers, and apospory.
2. Sexually, it is either dioecious or monoecious. Antheridia and archegonia develop on the dorsal surface of the thallus. Fertilization occurs when antherozoids are released from the antheridia and swim via chemotaxis to fertilize the egg in the archegonium, forming a zygote.
3. The zygote develops into a sporophyte that consists of a
This document provides an overview of a phycology and phycology lab course, including required textbooks, attendance policies, and syllabus details. The course will cover topics like algal taxonomy, growth, losses, and ecology. Students will learn about the diversity of algae including their structures, forms, habitats, and roles in ecosystems.
Algae are a diverse group of simple plant-like organisms ranging from unicellular to multicellular forms. They are typically photosynthetic and aquatic, lacking true roots, stems, leaves, and vascular tissue. Algae are classified into several divisions including green algae, red algae, brown algae, diatoms, dinoflagellates, and cyanobacteria (blue-green algae). Each division contains many distinct species that vary in habitat, structure, pigmentation and other characteristics. Algae play an important role as primary producers in many ecosystems.
This document discusses the classification and characteristics of different algal groups, including:
- Fritsch classified algae into 11 classes including Chlorophyceae, Xanthophyceae, and Cyanophyceae.
- Algae exhibit diverse morphologies and habitats, from single-celled to complex thalli. They are found in various aquatic and terrestrial environments.
- Algae reproduce both sexually, through processes like isogamy and oogamy, and asexually, through fragmentation, spores, and cell division. Different algal groups display diverse reproductive strategies.
Algae are photosynthetic organisms that live in or near water. They come in unicellular and multicellular forms and lack internal structures for transporting water and materials found in plants. Early experiments showed that algae use red and blue light for photosynthesis. Algae have evolved additional chlorophylls and accessory pigments to absorb different wavelengths of light and help with photosynthesis in aquatic environments where water absorbs much of the sun's energy. They are classified based on their chlorophyll and pigments.
1) Ciliated protozoans like Fabrea salina and Euplotes can be an important live food for fish larvae due to their abundance in coastal waters, small size similar to copepod nauplii, and ability to grow well on inert foods which is easier for aquaculture.
2) The document describes methods for culturing different ciliate protozoans like Fabrea salina that have advantages as a live food for fish larvae, such as small size, smooth cell wall, short generation time, and ability to form cysts that can remain viable.
3) The experiments conducted cultured Fabrea salina in 2L flasks with algae as food, under continuous light and measured
- Algae are a diverse group of photosynthetic organisms ranging from unicellular to multicellular forms like giant kelp. They lack complex tissues and organs found in land plants.
- Algae are classified as eukaryotes and conduct photosynthesis within membrane-bound chloroplasts. Their chloroplasts differ depending on endosymbiotic events in their lineages.
- Some algae form symbiotic relationships where they supply photosynthates to host organisms in exchange for protection, such as in lichens and coral reefs.
Sarcodinids are amoeboid protozoa that were formerly grouped with flagellates. They contain a single nucleus and contractile vacuoles. Their shapes range from amorphous to highly structured. Most feed on particulate material but some house photosynthetic algae. They reproduce asexually by binary or multiple fission. Some produce gametes for sexual reproduction. Encystment provides protection in unfavorable conditions.
Cercozoans, Radiolarians, Amoebas, And Redguest073ed23
This document summarizes several protist clades including cercozoans, radiolarians, amoebas, and various algae. Cercozoans and radiolarians are newly formed clades that contain amoebas with thread-like pseudopodia. Amoebazoans contain traditional amoebas like gymnamoebas and entamoebas as well as slime molds. Red and green algae are the closest relatives to land plants and arose through endosymbiosis. Examples are provided for representative organisms from each clade.
ALGAE & PROTOZOA1 seminar prepared by student.pptxaaliyabindhsaeed
Algae and protozoa are important microorganisms. Algae are photosynthetic, eukaryotic microorganisms found in aquatic and moist environments. They vary from unicellular to multicellular forms and can be divided into classes based on pigmentation. Protozoa are also unicellular eukaryotes that are generally heterotrophic. They exist in a variety of habitats and have various locomotory structures. Both algae and protozoa reproduce through asexual and sexual means. They play key roles in ecosystems and have economic uses including food, industrial applications, sewage treatment and more.
Similar to Fabrea salina, the salt loving ciliate (20)
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
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G. N. Hotos, Messolonghi Greece - 2018
Fabrea salina Henneguy, 1890. A heterotrichous ciliate thriving in
hypersalinity
George N. Hotos
Plankton Culture Laboratory, Dep. of Aquaculture & Fisheries Technology
Techn. Educ. Inst. (T.E.I.) of W. Greece, 30200 Messolonghi
ghotos@teiwest.gr
It was some years before when I was for the first time fascinated by the most prominent ciliate
protozoan swarming the extremely saline waters sampled from the Messolonghi evaporation
ponds of the local salt-works. This prominent ciliate is Fabrea salina and since then I kept it
constantly in my laboratory exposing it to various experimental trials concerning food, light,
salinity etc.
First of all I should make it clear that culturing protozoa or heterotrophic protists in general is not
so easy as expected. From my samples over the years I found the hard truth that attempting to
isolate each particular species and place it in small vials filled with the appropriate water (that is
with salinity and temperature as close as possible to the sampled water) is not a solid road to
success. Most of them will soon vanish even if you additionally supply them with various food
(algae, yeast, smashed organics, let alone the pre-supposedly existence of bacterial flora). Limited
success offered only some ciliates like Condylostoma, Paramecium (marine species) or Chilomonas
and that not for long. I should nevertheless admit that the hypotrichid Euplotes is the exception as
it multiplies so fast that not only there is no difficulty in culturing it but rather it is a real intruder
(better to say a pest) in almost every other culture, demanding for frequent filtration of the water
(50-80 μm nylon mesh) in order to get rid of it. Next to Euplotes in terms of easy culturing is
Fabrea salina and additionally Fabrea is not disturbed at all in multiplication by the simultaneous
presence of Euplotes. On the contrary it seems to do better if Euplotes is near-by. Sometimes for
reasons not elucidated yet, the population of Euplotes in the Fabrea's culture vessel recedes after
some days and eventually totally vanishes. This phenomenon is not presented in other ciliates
cultures where in mixtures of ciliate species Euplotes soon dominates.
Fabrea salina is cosmopolitan and (although not yet firmly established) seems to be the same
species all over the world's salty lakes. My purpose here is not a scientific paper but rather a free
style text to introduce Fabrea to scholars interested in microbiota from a naturalistic point of
view.
First of all the appearance of Fabrea in terms of shape, color and movement cannot be mistaken
and easily the microscope observer can be focused on it among various ciliates in the droplet of
water. The size of Fabrea is highly variable and for reasons not understood there can be met
populations with small individuals around 100 - 150 μm in length and populations with big ones
about 300-350 μm with all in between sizes occurring at times, either mixed with medium or big
individuals. I use the term population in order to point out the fact that what I mention above
comes from cultured specimens kept in small vials (4-200 ml) and that occasionally from a long
kept population of big Fabrea after some time small individuals emerge, dominate and keep so for
long, the opposite never occurred (from small individuals to emerge "bigs"). This phenomenon is
really puzzling and in spite of experimentation creating several microenvironments no pattern was
detected. At this point to make clear, that this size variation refers to populations and not to
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G. N. Hotos, Messolonghi Greece - 2018
young daughter cells ensuing after cell division that are small and grow to maximum size after
feeding. The small individuals are most of the time rather sluggish, reproduce at a lower rate or
not at all and feed less (as it is seen from the negligible clearance of microalgae feed).
Description: Body length in vivo along the long axis about 180-350 μm, usually spherical, ovoid or
tear-shaped with a slightly flattened and triangular-shaped anterior portion (snout) that is about
25% to 35% cell length (and tapers as proboscis). Cell size among individuals (excluding the
anterior pointed portion) highly variable. Insight the cell only a slight metabolic turbulence is seen.
Its pellicle is thin and flexible and with a roughened appearance of the cell's outline. Many tiny,
colorless cortical granules are evident. The protoplasm is colorless or slightly yellow-grayish, often
appearing opaque due to thickness of cell and numerous inclusions. A prominent band-like and
irregularly shaped macronucleus is seen when not obscured by vacuolated food inclusions. Many
micronuclei, although inconspicuous, are dispersed in the cytoplasm. About 150 inconspicuous
somatic kineties run along the cell composed of densely packed dikinetids. Adoral zone with about
200 membranelles. It exhibits almost continuous linear locomotion in a slightly strobilized manner
but sometime stops and looks suspended or drifting. It can withstand salinities from normal
seawater (35 ppt) to highly hypersaline water more than 180 ppt although its upper tolerance is
not exactly documented.
Classification
KINGDOM: Protista
PHYLUM: Ciliophora
SUBPHYLUM: Postciliodesmatophora
CLASS: Heterotrichea
ORDER: Heterotrichida
FAMILY: Climacostomidae
GENUS: Fabrea
SPECIES: Fabrea salina (to be named by its discoverer, Fabrea Henneguy in 1890)
Figure 1. A typical image of Fabrea salina. In (A) the specimen has a long wide triangularly shaped
snout with no proboscis. It is heavily vacuolated and in the front-most part of the adoral zone of
membranelles (AZM) a dark colored area is prominent. All around the cell are numerous coccoid
and filamentous cyanobacteria. In (B) the snout is shaped in proboscis. The cilia are evident
covering the whole outline of the cell.
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G. N. Hotos, Messolonghi Greece - 2018
The salinity tolerance of this ciliate is notorious as it is able to thrive even at the extremes (more
than 180 ppt) where (as it is widely and generally believed) only Dunaliella and Artemia reign the
ponds. In reality at the extreme salinities a whole array of life forms exists and "prospers". There
are archaea, cyanobacteria (both coccoid and filamentous), Ateromonas gracilis the chlorophyte
"companion" of Dunaliella, Fabrea salina and the metazoans are only represented by various
Artemia species (depending on locality).
Figure 2. Fabrea salina fed various algal species. (A) fed Dunaliella salina, with both carotenoid
full (red) and normal (green) cells, an indication of salinity (~150 ppt) where Dunaliella starts
carotenogenesis. (B), vacuoles full of the cryptophyte Rhodomonas salina in the process of
digestion from a laboratory culture at 35 ppt salinity. (C & D), with vacuoles loaded with ingested
Asteromonas gracilis from laboratory cultures at 90 ppt. Noteworthy the snout-less form of
Fabrea in C and the proboscis form in D.
It is really curious that this hypersalinity microbiota remains for the most part poorly recorded in
the literature. The literature has not yet articulated it in a definite web-scheme that encompass
abundance, succession, etc. Anyway, concerning Fabrea it is sure that feeds upon any kind of algae
(cyanobacterial or eucaryotic) and probably bacteria. But when salinity reaches the far extremes
more than 250 ppt then it succumbs leaving only Dunaliella and the archaean Halobacterium
salinarum to color the water orange-red.
Talking about salinity it must be emphasized that Fabrea can live and multiply in normal sea-water
(~35 ppt) the same as in hypersalinity and furthermore is doing better in lower salinities as it faces
less osmotic pressure, higher dissolved oxygen and has more options of suspended live food. I
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G. N. Hotos, Messolonghi Greece - 2018
should also emphasize that Fabrea is exclusively a planktonic creature (not benthonic) never
feeding on the bottom mat of the ponds and in culture conditions presents a uniform dispersal in
the water volume of the culture vessel.
Conjugation in Fabrea is a rare event (I only noticed it 2-3 times in my multiyear cultures). It
multiplies by cell fission using two ways. First the cell elongates and in an area near the middle
starts to form a depression that delineates a front (snout part) and a rear bulge that after some
time create two Fabrea resembling daughter cells united either by a common protoplasm in the
"neck" front area or by a kind of linkage of the type "tail-to-snout". Eventually the protoplasmic
connection thins out to nothing but a very thin highly tensible thread that eventually will break as
the cells move independently. The whole process (from the beginning till separation) lasts
somewhat between 4 to 5 hours and in good conditions (temperature above 22 o
C, plenty of food)
the generation time (doubling time) of Fabrea lies somewhere between 16-24 hours, not bad at all
for culturing such a big sized ciliate. There is a question however if the "neck-connected" cells are
the result of cell fission or a stage of the conjugation process. I am inclined to accept cell division
as evidenced from the separation effort seen in several of my videos.
Figure 3. Fabrea salina separation of cells by cell fission. In (A) can be seen the protoplasmic
connection at the "neck" area of the daughter cells (in the big depicture) and in the same photo
properly arranged (from lower magnification) three different positions of stretching the
connection by the movement of each daughter cell away from each other. It must be admitted
however that this picture can be as well an episode of the conjugation procedure. In (B) the
daughter cells (close to separation) are united in a "tail-to-snout" manner.
The most fascinating feature of Fabrea for microscopy observers is the elegant smooth way of
scrolling around in the water. It swims rather slow and at times accelerates with or without
strobilization. Sometimes swirls for a while and sometimes goes forwards and backwards for no
obvious reason. It is very easy to take a sample of an individual Fabrea as it can be spotted easily
and sucked properly by a microtubule even at the lower magnification of a dissecting microscope.
A peculiar thing frequently encountered in culture vials is the local concentration of many
individuals at certain peripheral areas leaving the center area almost devoid of cells. This happens
when the population multiplies fast but has not reached yet its maximum density. When
maximum density has attained (varies between 50-110 ind./ml) then all the individuals are evenly
dispersed in the whole volume and no patches of crowding are created any more.
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G. N. Hotos, Messolonghi Greece - 2018
In my cultures I have observed cases of co-existence of Fabrea with various species of ciliates.
These ciliates although at times are abundant they never dominate as populations and eventually
Fabrea restrict them in nothing but a few cells.
The other fascinating feature of Fabrea is the vortex creating by its huge "mouth" region that is
located inside the spiral funnel shaped by its adoral zone of membranelles (AZM). This sucking
area is perhaps the most prominent region that everyone spots when examines Fabrea. The cilia in
this region are very long and their rapid movement gives the impression of a rotary machine
creating a whirl dragging in anything that falls in its action radius. Indeed we can see algal cells to
reach the area, then to be forced in a cycling movement and finally by a rapid suction to be
transferred inside the cytostome and then to be thrown in the cytoplasm where rapidly a vacuole
engulfs them.
Figure 4. Fabrea salina. In (A) we can see the peculiar "S" shape of the macronucleus (depicted
and clearly visible as lightly colored) and the circular shape of the AZM creating the big "mouth"
area of the cell. In (B) the long cilia of the AZM in the mouth area are very prominent and also
several vacuoles filled with digested material. In (C) Fabrea is surrounded by the ciliate
Hemiophrys and in (D) a "bas-relief" picture of several Fabrea with many vacuoles accompanied by
several ciliates Euplotes. These pictures are also useful for comparison of sizes between a very big
ciliate (>200 μm) as Fabrea and medium to small ciliates (~50-100 μm) as Euplotes and
Hemiophrys.
In cases of abundant algal availability Fabrea stuffs its cell with algae and its protoplasm bursts
with numerous vacuoles full of green, pink or brown algal material depending on the particular
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G. N. Hotos, Messolonghi Greece - 2018
color of the algal species consumed. However not all algal cells are digested as many of them are
frequently expelled through evacuation of the content of some vacuoles to the external medium
and upon their freed acquire mobility like nothing had happened. It is also probable that some of
the algae are not digested but instead they are used as symbionts to provide Fabrea with their
photosynthetic products. So, based on the above, it is postulated that on abundance of food
material Fabrea get it in excess, store it in vacuoles and then digests the proper amount at its
ease.
Microalgae seems to be an excellent feed-stuff for Fabrea and especially the big sized and
flagellated ones like Dunaliella, Asteromonas, Tetraselmis, Isochrysis or Rhodomonas. Non
flagellated species like Chlorella or Nannochloropsis proved inferior to their flagellated
counterparts. Coccoid cyanobacteria like Synechococcus sp. are also consumed but to a lesser
degree. Filamentous cyanobacteria like Oscillatoria, Lyngbya, etc have never been observed (at
least by me) to be consumed by Fabrea. I never met incidents of Fabrea consuming other ciliates
nor cannibalization on its own species.
Figure 5. Fabrea salina. In (A) a close look at the "mouth" region with the big cilia on the depicted
cyclical part of the AZM and an algal cell just sucked in. In (B) a scene with the evacuation of a
vacuole while other vacuoles are stuffed with algae.
The most puzzling part in Fabrea's life story is its polymorphism regarding its overall cell shape, its
size, its snout length and the presence and relative size of proboscis (the variously elongated,
blunt or pointed, curved or straight, part of the snout region). Probably this polymorphism is not
due to genetic differentiation but rather due to an inherent ability to transform the cell into forms
that suit transient needs of living. This hypothesis is strengthened by observation of a uniform
Fabrea population that is composed of quite big individuals (~300 μm). The population kept in
experimental conditions with stable temperature (~20 o
C) and plenty of algal food is doing fine
and multiplies intensively.
As time is elapsing the population reaches a maximum and gradually starts to create more and
more smaller individuals that have all possible shapes like those depicted in Figure 6 intermingled
with the initial big "normal" cells. In some cultures the small individuals stabilize in number and
their proportion to the population is not changed till the collapse of the whole culture. In other
cases the smaller individuals take over in proportion and in some cases the whole culture is
composed exclusively of them. A prominent characteristic of these smaller cells is their lower
reproductive rate and the lower feeding rate as they are most of the time quite transparent with
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G. N. Hotos, Messolonghi Greece - 2018
lower inclusions and never heavily vacuolated with full of algae vacuoles. Additionally no matter if
the culture conditions are suitable (replacement of fresh water, temperature, plenty of food) the
small cells never initiate again a population of big individuals.
The above phenomenon can probably be attributed to the deterioration of culture conditions but
its irreversibility is highly puzzling and demands thorough investigation. Nevertheless for those
intending to culture Fabrea continuously, the keeping of big individuals can be attained by
frequent seeding new cultures with cells from a pre-existing culture that has not been left for so
long in the same vessel.
Figure 6. Polymorphism in Fabrea salina. In (A) an array of various cell forms exhibiting variations
in every part of the cell (length, width, mouth region, proboscis). In (B) the proboscis is long and
curved. In (C) that comes from extreme salinity (180 ppt) the whole snout area is curved, the cilia
of the proboscis are very long and the AZM very small. In (D) is the most common snout form of
Fabrea, to be considered (in an arbitrary way) as the ordinary and prevalent form of Fabrea.
Figure 7.
Polymorphism of
Fabrea salina. This
collage sums up some
of the most frequently
encountered cell shapes
in cultures of Fabrea at
medium to high
salinities (35-110 ppt).
They are from the big
sized Fabrea (~300 μm)
and most of the
variation lays on the
snout area.
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G. N. Hotos, Messolonghi Greece - 2018
Another aspect of importance, puzzling as well and quite unexplained, is the encystment of
Fabrea. It is well known based on sampling from natural sites that Fabrea encysts and enters
cryptobiosis in order to endure the evaporation of hypersaline ponds. Its cysts are buried in the
mud, withstand dryness and transform to active cells upon the re-flooding of the area. This
adaptation widely spread and common among protozoa helps the colonization of new areas as the
cysts are transferred there either by mud stuck on birds or by wind action. The puzzling thing is
that encystment occurs also in culture vessels even when conditions are far from being adverse.
This happens suddenly and not for all the individuals in captivity nor in all culturing vessels that
keep the same population in the same exactly conditions. There is no trend nor a pattern and
seems that the phenomenon is governed by chance. The process starts with a lowering of the
speed of movement, the rounding of the body and the darkening of the cell's color. The cell moves
to the bottom and the beating of cilia gradually ceases till there are no cilia observed. Around the
cell a thick membranous material is created and the cell turns into a perfect dark brown sphere
with amorphous inside material (no vacuoles, no AZM, no visible macronucleus). I have kept such
cysts for about 1,5 years completely dry in salt crystals and I revived a c.f. 50% of them by
watering their mass. The encystment of Fabrea can be very useful if one wishes to keep a stock of
them but till the elucidation of a certain recipe for accomplishing this at will, it is nothing but
experimentation.
Figure 8. In (A-B-C) 3 steps of transformation of a Fabrea salina cell to a cyst. In (D-E-F) several
views of the cysts in the process of awakening. (C) and (F) are cysts in the terminal stage but in (F)
the cyst starts to awake creating a characteristic funnel shaped opening on the thick wall.
Fabrea salina can also reproduce by budding although this method is rarely employed by the cell
and its triggering cause is unknown. It starts by an initial bulging of the cell in any location that
eventually forms a small spherical outgrowth connected with the cell by a stretchable
protoplasmic band. Gradually in the course of 1-2 hours the connecting band becomes thinner and
thinner while the budding sphere is not changing in volume. Eventually the connection becomes
nothing but a thin thread of protoplasm that eventually breaks and the sphere is freed. The sphere
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G. N. Hotos, Messolonghi Greece - 2018
starts its independent life and cilia are formed around this initial cell. Gradually it transforms to
the typical Fabrea cell with all its organelles and grows to the normal size.
Figure 9. The process of budding in Fabrea salina. In (A), (B) and (C) three different stages of
protoplasmic connection between the spherical outgrowth and cell proper. Note the thinning of
the protoplasmic connection where in (C) is nothing but a thin thread ready to be broken. In (D)
the freed spherical bud and in (E) a closer look with the formation of its first vacuole.
In some lecture notes that I found in the web I noticed that some authors claim that budding does
not occur in marine ciliates. Based on evidence from my numerous samples of marine type ciliates,
this is not accurate as I have recorded budding occurring not only in Fabrea but also in Euplotes,
Holophrya, Condylostoma and I deduce that is common probably in other species as well.
Fabrea salina can be useful both as an ideal tool for teaching protozoa and for experimentation in
terms of osmoregulation, toxicology and as a live feed to be used in marine fish-hatcheries. In
reality it is maybe the only alternative to the rotifer Brachionus plicatilis that is the only
appropriate till today live food for the newly hatched larvae of various marine fish. Its size, color,
movement, planktonic nature and constituents resembles much those of Brachionus. Its mono-
cellular nature and its simple way of multiplication permits genetic manipulation to create
appropriate strains that could serve better its role as a live feed and for other purposes.
The present work is not a scientific paper (experimentation or review) nor a monograph. It must
be seen as an encyclopedian-type essay in order to support information for biology students in a
simple and comprehensive way, based on the experience of a person fond of naturalistic
investigations.
For the end of this essay I think it is useful to present an overall sketch of Fabrea's cell to clarify
the terminology used for describing its morphology. Figure 10 is the most representative and
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G. N. Hotos, Messolonghi Greece - 2018
beautiful drawing (from my personal point of view) of Fabrea taken from the work of Ji Hye Ki &
Mann Kyoon Shin (2015) that I cite in the literature.
Figure 10. Fabrea salina. Typical body shape (left), arrangement and pattern of cortical granules,
arrows indicate each somatic kineties (center) and another more detailed view of the cell's outline
to show the many kineties that transverse the cell (right). Arrows indicate micronuclei.
CC, part of condensed cortical granules; FV, food vacuole; AZM, adoral zone of membranelles; MA,
macronucleus; P, proboscis; PK, peristomial kinety; PM, paroral membrane; PR, preoral kineties.
Scale bars: Left and right=50 μm, center=5 μm (after Ji Hye Kim & Mann Kyoon Shin, 2015).
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G. N. Hotos, Messolonghi Greece - 2018
SELECTED LITERATURE
Augustin, H. & Foissner, W, 1992. Morphologie und Ökologie einiger Ciliaten (Progozoa:
Ciliophora) aus dem Belebtschlamm. Archiv für Protistenkunde, 141:243-283. http://dx.
doi.org/10.1016/S0003-9365(11)80057-6
Henneguy, L., F., 1890. Sur un Infusoire hétérotriche Fabrea salina nov. sp. Annales de
Micrographie, 3:118-135.
Hotos, G., 2018. Protists, Cyanobacteria, Rotifers and Crustacea from the hypersaline lakes
of Messolonghi saltworks (W. Greece). 10th
World Salt Symposium, 2018, Park city, Utah,
U.S.A. 19-21 Jun 2018.
Hotos, G., 2018. Feeding with various microalgae the salt “loving” ciliate Fabrea salina in
normal salinity 35 ppt. HydroMedit 2018, 3rd
Intern. Cong. on Appl. Icth. & Aquatic Envir,
Volos (Greece), 8-11 Nov. 2018.
Korovesis, A. K., Hotos, G. & G. Zalidis, 2018. The role of the ciliate protozoan Fabrea salina
in solar salt production. 10th
World Salt Symposium, 2018, Park city, Utah, U.S.A., 19-21
Jun 2018.
Lynn, D., 2008. The ciliated protozoa. Characterization, classification, and guide to the
literature. 3rd ed. Springer, Dordrecht, pp. 1-605.
Ji Hye Kim & Mann Kyoon Shin, 2015. Novel discovery of two heterotrichid ciliates,
Climacostomum virens and Fabrea salina (Cliophora: Heterotrichea: Heterotrichida) in
Korea. Anim. Syst. Evol. Divers. 31(3): 182-190.
Pandey, D., B., Yeragi, G., S., Reddy, K., A. & Atsushi Hagiwara, 2008. Life strategies and
aquacultural usability of a hypersaline ciliate, Fabrea salina. Current Science, 94(3), 307-
309.
For videos about Fabrea those listed below created by the author can be useful.
https://www.youtube.com/watch?v=zbMe-bGWtX4 (Fabrea salina, evacuation of a vacuole)
https://www.youtube.com/watch?v=1BEbvQAV7Ng (Fabrea salina, budding)
https://www.youtube.com/watch?v=ftmktGpurRY (Fabrea salina, division)
https://www.youtube.com/watch?v=QGQSKP2ZGxw (Fabrea salina, population)
https://www.linkedin.com/feed/update/urn:li:activity:6464178208781799424 (Fabrea salina)
https://www.linkedin.com/feed/update/urn:li:activity:6451864552236814336 (Fabrea salina,
vacuoles filled with algae)