Rotifers are popularly called as wheel animalcules. They are an important group of live food organisms for use in aqua hatcheries. Brachionus, which is the most known form of all rotifers, serve as an ideal starter diet for early larval stages of many fish and prawn species in marine as well as freshwater. Species of the genus Brachionus (Brachionidae: Rotifera) are well represented in different water bodies worldwide (Pejler, 1977). Depending on the mouth size of the cultured organisms, small (50 to 110 micron length) or large (100 to 200 micron length) rotifers are used. There are about 2,500 species of rotifers have been known from global freshwater, brackish water, and seawater. B. plicatilis is the species used most commonly to feed fish larvae in hatcheries around the world. It is a euryhaline species, small and slow swimming, with good nutritional value. It is well suited to mass culture because it is prolific and tolerates a wide variety of environmental conditions. The rotifer, B. plicatilis and B. rotundiformis, have been indispensable as a live food for mass larval rearing of many aquatic organisms (Maruyama et al., 1997). By way of significant developments in larval rearing technology of fishes, demand for the rotifer is further increasing.
Eggs and larvae identification biology in fin fish Ashish sahu
Characters most useful in identification of fish eggs are the following: (1) egg shape-spherical, ellipsoidal, irregular, or oth- erwise; (2) egg size-fish eggs range in size from 0.5 to 26.0 mm; (3) oil globules-presence or-absence.
Identification of Fish Eggs - SWFSCswfsc.noaa.gov › publications
Search for: How can you tell a fish egg?
Eggs and larvae identification biology in fin fish Ashish sahu
Characters most useful in identification of fish eggs are the following: (1) egg shape-spherical, ellipsoidal, irregular, or oth- erwise; (2) egg size-fish eggs range in size from 0.5 to 26.0 mm; (3) oil globules-presence or-absence.
Identification of Fish Eggs - SWFSCswfsc.noaa.gov › publications
Search for: How can you tell a fish egg?
.DEFINITION OF FISH PHARMACOLOGY:
“Fish pharmacology is essential for undertaking treatment of fishes using any therapeutic chemicals or drugs.”
“Pharmacology is the study of the interaction of chemicals with living system.”
“Pharmacology” is morden science which correlated other biological sciences, eg., Biochemistry , Physiology Microbiology , Medicine , and Genetics.
“Pharmacology is the branch of biology concerned with the study of drug action.”
“Pharmacology is the study of drugs including their origins, history, uses, and properties. It mainly focuses on the actions of drugs on the body.”
“Pharmacology is the study of drugs and theire actions on the body”.
“Pharmacology is the study of substance that interact with living systems through chemical process, especially by binding to regulatory molecules &activating or inhibiting normal body process.
Fig. 1
3. HISTORY OF FISH PHARMACOLGY:
Pharmacology emerged as its own discipline in the 19th Century, branching off from research done in fields of science such as organic chemistry and physiology. Oswald Schmiedeberg, who was born in what is now Latvia in 1838, is considered the father of pharmacology. His doctoral thesis was on the measurement of chloroform levels in blood, and he went on to become a professor of pharmacology at the University of Strasburg, where he ran an institute of pharmacology. There, he studied chloroform, which was used as an anesthetic, chloral hydrate, a sedative and hypnotic, and muscarine, a compound isolated from the mushroom Amanita muscaria that stimulates the parasympathetic nervous system and has been used to treat various diseases such as glaucoma.
In 1890, John Jacob Abel became the first pharmacology chair in the United States, at the University of Michigan. He later went to Johns Hopkins University in Baltimore. Abel was the first to isolate the hormone epinephrine from the adrenal gland, isolate histamine from the pituitary gland, and make pure crystalline insulin. Animals such as dogs, cats, pigeons, and frogs were used to test pharmacological substances. Humans were even used as test subjects. Sometimes they suffered through severe adverse effects from these substances, such as when the German pharmacist Friedrich Serturner and three of his friends had poisoning for several days from an alkaloid that Serturner had isolated from opium. This alkaloid was later named morphine, after the Ancient Greek god of sleep, Morpheus.
Oswald Schmiedeberg was a brilliant scientist. He studied the pharmacology of various compounds, including chloroform, and published an important text called the Outline of Pharmacology. There, he studied chloroform, which was used as an anesthetic, chloral hydrate, a sedative and hypnotic, and muscarine, a compound isolated from the mush to the field, Schmiedeberg is now known as 'the father of pharmacology'.
Nutritional requirement of cultivable fin fish: larvae, juveniles and adultsDebiprasad1997
Fish is among the healthiest foods on the planet. It is loaded with important nutrients, such as protein and vitamin D. Fish is also the world's best source of omega-3 fatty acids, which are incredibly important for human body and brain.
Manufactured feeds are an important part of modern commercial aquaculture, providing the balanced nutrition needed by farmed fish.
In the development of modern aquaculture, starting in the 1970s, fishmeal and fish oil were key components of the feeds for these species. They are combined with other ingredients such as vegetable proteins, cereal grains, vitamins and minerals and formed into feed pellets.
The global supply of fish meal and fish oil is finite and fully utilized. Alternative or nontraditional feedstuffs may differ in terms of taste, smell, texture, and color, as well as nutrient composition, from the traditional feedstuffs, which are produced largely from the natural prey of the fish being raised. Alternative feedstuffs may also contain compounds and antinutritional factors that affect digestive or sensory physiology.
Another important area of fish nutrition for the next 20 years will be larval fish nutrition. Currently, the cost and difficulty of rearing a great number of species from the first feeding to the juvenile stage are the most severe bottlenecks to the development of aquaculture production of nontraditional species.
All the freshwater prawns that have been cultured so far belong to the genus Macrobrachium , Bate 1868, the largest genus of the family Palaemonidae. About 200 species have been described, almost all of which live in freshwater at least for part of their life.
The giant river prawn, Macrobrachium rosenbergii , was one of the first species to become scientifically known , the first recognizable illustration appearing in 1705. The nomenclature of freshwater prawns, both on a generic and a species level has had quite a muddled history. In the past, generic names have included Cancer (Astacus) and Palaemon. Previous names of M. rosenbergii have included Palaemon carcinus, P. dacqueti and P. rosenbergii ( De Man 1879) became universally accepted.
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries. Fish seed transportation is a process by which transfer of fish seed from the hatchery or place of collection to the rearing ponds.
Virtual population analysis (VPA) is a cohort modeling technique commonly used in fisheries science for reconstructing historical fish numbers at age using information on death of individuals each year. This death is usually partitioned into catch by fisheries and natural mortality. VPA is virtual in the sense that the population size is not observed or …
A bureau de change? What's that got to do with the price of fish? Quite a lot, actually. Well over two thirds of the world's farmed common carp is produced in China. As a result, it is believed that the strength of the Chinese yuan can have a significant effect on the market price of this fish worldwide.
Evolution of fisheries sector in BangladeshMD. ZANE ALAM
Bangladesh is a densely populated country of 147 570 km2 with a population of 160
million people. It is fortunate in having an extensive water resource in the form of ponds,
natural depressions (haors and beels ), lakes, canals, rivers and estuaries covering an area
of 47,03,658 ha .
The present per capita annual fish consumption in Bangladesh stands at about 14 kg/year
against a recommended minimum requirement of 18 kg/year; hence, there is still need to
improve fish consumption in the country.
Fisheries in Bangladesh are diverse, there are about 795 native species of fish and shrimp
in the fresh and marine waters of Bangladesh and 12 exotic species that have been
introduced. In addition, there are 10 species of pearl bearing bivalves, 12 species of
edible tortoise and turtle, 15 species of crab and 3 species of lobster.
.DEFINITION OF FISH PHARMACOLOGY:
“Fish pharmacology is essential for undertaking treatment of fishes using any therapeutic chemicals or drugs.”
“Pharmacology is the study of the interaction of chemicals with living system.”
“Pharmacology” is morden science which correlated other biological sciences, eg., Biochemistry , Physiology Microbiology , Medicine , and Genetics.
“Pharmacology is the branch of biology concerned with the study of drug action.”
“Pharmacology is the study of drugs including their origins, history, uses, and properties. It mainly focuses on the actions of drugs on the body.”
“Pharmacology is the study of drugs and theire actions on the body”.
“Pharmacology is the study of substance that interact with living systems through chemical process, especially by binding to regulatory molecules &activating or inhibiting normal body process.
Fig. 1
3. HISTORY OF FISH PHARMACOLGY:
Pharmacology emerged as its own discipline in the 19th Century, branching off from research done in fields of science such as organic chemistry and physiology. Oswald Schmiedeberg, who was born in what is now Latvia in 1838, is considered the father of pharmacology. His doctoral thesis was on the measurement of chloroform levels in blood, and he went on to become a professor of pharmacology at the University of Strasburg, where he ran an institute of pharmacology. There, he studied chloroform, which was used as an anesthetic, chloral hydrate, a sedative and hypnotic, and muscarine, a compound isolated from the mushroom Amanita muscaria that stimulates the parasympathetic nervous system and has been used to treat various diseases such as glaucoma.
In 1890, John Jacob Abel became the first pharmacology chair in the United States, at the University of Michigan. He later went to Johns Hopkins University in Baltimore. Abel was the first to isolate the hormone epinephrine from the adrenal gland, isolate histamine from the pituitary gland, and make pure crystalline insulin. Animals such as dogs, cats, pigeons, and frogs were used to test pharmacological substances. Humans were even used as test subjects. Sometimes they suffered through severe adverse effects from these substances, such as when the German pharmacist Friedrich Serturner and three of his friends had poisoning for several days from an alkaloid that Serturner had isolated from opium. This alkaloid was later named morphine, after the Ancient Greek god of sleep, Morpheus.
Oswald Schmiedeberg was a brilliant scientist. He studied the pharmacology of various compounds, including chloroform, and published an important text called the Outline of Pharmacology. There, he studied chloroform, which was used as an anesthetic, chloral hydrate, a sedative and hypnotic, and muscarine, a compound isolated from the mush to the field, Schmiedeberg is now known as 'the father of pharmacology'.
Nutritional requirement of cultivable fin fish: larvae, juveniles and adultsDebiprasad1997
Fish is among the healthiest foods on the planet. It is loaded with important nutrients, such as protein and vitamin D. Fish is also the world's best source of omega-3 fatty acids, which are incredibly important for human body and brain.
Manufactured feeds are an important part of modern commercial aquaculture, providing the balanced nutrition needed by farmed fish.
In the development of modern aquaculture, starting in the 1970s, fishmeal and fish oil were key components of the feeds for these species. They are combined with other ingredients such as vegetable proteins, cereal grains, vitamins and minerals and formed into feed pellets.
The global supply of fish meal and fish oil is finite and fully utilized. Alternative or nontraditional feedstuffs may differ in terms of taste, smell, texture, and color, as well as nutrient composition, from the traditional feedstuffs, which are produced largely from the natural prey of the fish being raised. Alternative feedstuffs may also contain compounds and antinutritional factors that affect digestive or sensory physiology.
Another important area of fish nutrition for the next 20 years will be larval fish nutrition. Currently, the cost and difficulty of rearing a great number of species from the first feeding to the juvenile stage are the most severe bottlenecks to the development of aquaculture production of nontraditional species.
All the freshwater prawns that have been cultured so far belong to the genus Macrobrachium , Bate 1868, the largest genus of the family Palaemonidae. About 200 species have been described, almost all of which live in freshwater at least for part of their life.
The giant river prawn, Macrobrachium rosenbergii , was one of the first species to become scientifically known , the first recognizable illustration appearing in 1705. The nomenclature of freshwater prawns, both on a generic and a species level has had quite a muddled history. In the past, generic names have included Cancer (Astacus) and Palaemon. Previous names of M. rosenbergii have included Palaemon carcinus, P. dacqueti and P. rosenbergii ( De Man 1879) became universally accepted.
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries. Fish seed transportation is a process by which transfer of fish seed from the hatchery or place of collection to the rearing ponds.
Virtual population analysis (VPA) is a cohort modeling technique commonly used in fisheries science for reconstructing historical fish numbers at age using information on death of individuals each year. This death is usually partitioned into catch by fisheries and natural mortality. VPA is virtual in the sense that the population size is not observed or …
A bureau de change? What's that got to do with the price of fish? Quite a lot, actually. Well over two thirds of the world's farmed common carp is produced in China. As a result, it is believed that the strength of the Chinese yuan can have a significant effect on the market price of this fish worldwide.
Evolution of fisheries sector in BangladeshMD. ZANE ALAM
Bangladesh is a densely populated country of 147 570 km2 with a population of 160
million people. It is fortunate in having an extensive water resource in the form of ponds,
natural depressions (haors and beels ), lakes, canals, rivers and estuaries covering an area
of 47,03,658 ha .
The present per capita annual fish consumption in Bangladesh stands at about 14 kg/year
against a recommended minimum requirement of 18 kg/year; hence, there is still need to
improve fish consumption in the country.
Fisheries in Bangladesh are diverse, there are about 795 native species of fish and shrimp
in the fresh and marine waters of Bangladesh and 12 exotic species that have been
introduced. In addition, there are 10 species of pearl bearing bivalves, 12 species of
edible tortoise and turtle, 15 species of crab and 3 species of lobster.
Aquaculture Revolution in Bangladesh.pdfSadia Nabilah
Bangladesh has one of the largest and most active deltas, nourished by the Padma, Meghna, and Jamuna rivers. This increases the potential for fresh and brackish water capture and culture fisheries. Aquaculture is the fastest-growing enterprise in Bangladesh since the 1980s.
Aquaculture production is unevenly dispersed geographically with Asian countries contributing nearly 90% of global production; where, China is the largest producer in 2018, followed by India, Indonesia, Vietnam, and Bangladesh, respectively (FAO, 2020). According to FAO report The State of World Fisheries and Aquaculture 2018, Bangladesh ranked 5th in world aquaculture production. The aquaculture industry has worked out towards creating new possibilities and yet has to face some future challenges due to unwise practices and knowledge gaps.
Employment opportunities in the sector are a boon as well – official statistics show that the fisheries and aquaculture sectors (directly and indirectly) support more than 18 million people. The aquaculture sector has a high potential for the perspective on the economic development of the country.
As with any livestock industry in Bangladesh, there are a number of challenges that can impact the viability of aquaculture initiatives in future. Aquaculture can be no riskier than, say, poultry farming. We have to figure out what these challenges are and how both external and internal challenges can be managed through good project design.
The term “sustainability” or also “sustainable development”, often used as nothing more than a catch-phrase, has much more to offer. It is a concept to guarantee a livable environment for all people in the long term, encompassing at least three fundamental components of sustainable development, preservation of a functional environment, economic welfare and social equity. Accordingly, also in the field of aquaculture, aiming for sustainability requires not only the achievement of environmental objectives, but also to provide clear economic advantages for aquaculture farmers in the long term. However, the term “sustainability” is often diluted and weakened , being used by politicians, entrepreneurs and the public, in a general way on numerous occasions, very often in a superficial or misleading way and with an incorrect definition, just to exploit the positive , connotations of the term.
Aquaculture (less commonly spelled aquaculture), also known as aquafarming, is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other organisms. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish.
These topic contains global scenario of aquaculture, demand consumption scenario and present status of aquaculture in India. These presentation also contain constraints, future prospects and challenges in aquaculture. Different aquaculture practices throughout the world.
Best 10 Economic Importance Of Aquaculture.pdfProjitMondol1
Best 10 Economic Importance Of Aquaculture
Aquaculture
Fisheries and aquaculture make a big contribution to development in the areas of employment. Describing the importance of aquaculture is not an easy task. According to M. Shahbandeh, the number of people who were engaged in fishing and aquaculture amounted to around 40.34 million and 19.27 million respectively worldwide in 2016 and the number has been increasing day by day since 1995. The vast majority of them are from developing countries, working in fish production or fish raising, fish processing, harvesting, and small-scale fish business.
Importance of Aquaculture
Aquaculture; Image: aquaculturealliance.org
Table of Contents
Aquaculture
Aquaculture is the controlled process of rearing, breeding and harvesting of aquatic species, both animals and plants, especially for human consumption, though it is controlled aquatic environments like the oceans, lakes, rivers, ponds, and streams. It’s a similar conception to agriculture, but with fish instead of plants or livestock. It also serves various functions such as food production, restoration of threatened and endangered species populations, wild stock population enhancement, the building of aquariums, and fish cultures, and habitat restoration.
History of Aquaculture
The husbandry of fish is therefore not a new phenomenon. Ancient practices based on the modifications of natural bodies of water or wetlands to entrap young fish in enclosures until harvest have just evolved into more systematic and scientific methods and techniques.
Aquaculture has a long tradition, which is about 4 000 years, and form the beginning of the time man identified the importance of aquaculture.. Probably aquaculture began in China before very long ago, due to the wants of an emperor to have an unremitting supply of fish in his land. It is supposed that the proficiencies for keeping fish in ponds originated in China with fishermen who kept their extra catch alive temporarily in baskets submerged in rivers or small bodies of water created by damming one side of a river bed.(Ling, S.W,Aquaculture in Southeast Asia: A Historical Overview,A Washington Sea Grant Publication).
Another theory is that aquaculture arose from ancient practices for pinning down fish, with the operations steadily improving from trapping-holding to trapping-holding-growing, and finally into complete agriculture or farming practices.
Methods of Aquaculture
The methods of aquaculture’s farm-to-table process can differ from species to species. Generally, there are four stages of the production chain, starting in hatcheries and ending at the seafood counter in your grocery store. Four stages are:
stages of the production chain
Stages of Production; Image: Ruddra
Each of these stages may vary concerning its effect on the environment and the quality and safety of the seafood they produce.
The first stage in the aquaculture production chain is the hatchery. This is where the breeding of fish, hatch
REGIONAL WORKSHOP ON FISHERIES AND MARINE GENETIC RESOURCES AND THEIR AMELIOR...apaari
REGIONAL WORKSHOP ON FISHERIES AND MARINE GENETIC RESOURCES AND THEIR AMELIORATION COUNTRY STATUS REPORT – INDIA BY Kuldeep K. Lal & J K Jena Presented during the Regional Workshop on Underutilized Fish and Marine Genetic Resources and their Amelioration, 10-12 July 2019, Location: Colombo, Sri Lanka
Impact of stocking common carp (Cyprinus carpio) on production in some select...AbdullaAlAsif1
The present study was conducted in three seasonal beels in Gacha union under Gazipur sadar upazila in Gazipur district during the period from June 2015 to January 2016. The objectives of the study were to evaluate the impact of stocking common carp on the abundance and biodiversity of native fish species in seasonal beels. Three seasonal beels such as Baroholai, Makhna and Buridha which were connected with Turag River through different canals were selected to implement the study. Baroholai and Makhna beel were stocked with common carp fingerlings at 2500 per hectare. Buridha beel served as control. Necessary data were collected from the fishermen and lease holders of the concern beel through using structured questionnaire by survey method. A total of 42-43 species of fishes were recorded from stocked beel as against of 43 species in control beel. Shanon-Weiner diversity index averaged 2.58 in stocked beel as opposed to 2.68 for control beel. The studied beel had medium richness in terms of biodiversity and faunal abundances. Per hectare fish production was 522-577kg in stocked beels as compared to 365kg in control beel. Cyprinidae was the most abundant group contributing to the bulk of fishery yield. Surface feeder took a lead over other groups of fishes in stocked beel as opposed to bottom feeder in case of control beel. Bottom dwelling small catfishes seems to be affected in presence of common carp in the stocked beels. Control beel harboured increased number and quantity of catfishes. Fish productions in the seasonal beels were profitable. Per hectare total cost of fish production averaged tk 34976.67 as against of total gross return of tk 92683.67. Benefit cost ratio (BCR) was found to be 2.57-3.42 in stocked beel and 2.01 in control beel. Further researches are needed to precisely determine the possible consequences of stocking common carp in seasonal beels.
Exotic fishes belonging by nature or origin to another part of the world or brought in from abroad or foreign.
Exotic species are non-indigenous.
Aliens
Introduced in new area
Non-native
Different continent
Outside historic geographical range
Different ecosystem
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, "...a fishery is an activity leading to harvesting of fish. It may involve capture of wild fish or raising of fish through aquaculture.
Freshwater and coastal aquaculture development can benefit from internal and external experience for preventing environmental damage and for avoiding harmful effects of degradation on aquaculture resources. Strategies to compensate for the loss of aquatic fauna (e.g. due to physical obstructions) are directly linked to important environmental issues, such as the transfer of exotic species, the spread of diseases and loss of genetic diversity, eutrophication, impairment of aesthetic qualities and the disruption of indigenous fish stocks.
There presently, conceptual frameworks for aquatic environment management backed by legal and administrative tools to create or enforce ration systems for water management, land use or fisheries and aquaculture development strengthened by adaptive institutionalization.
Impacts of Climate Change in Coastal Aquaculture in Bangladesh : A Seminar Paperihn FreeStyle Corp.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average. Climate change may be limited to a specific region, or may occur across the whole Earth. Climate change may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming”. Climate change has both direct and indirect impacts on fish stocks which are exploited commercially. Direct effects act on physiology and behavior and alter growth, reproductive capacity, mortality and distribution. Indirect effects alter the productivity, structure and composition of the marine ecosystems on which fish depend for food. However, even though the year-on-year rate of anthropogenic climate change may seem slow, this is very rapid compared with previous natural change and the accumulative value produces a significant difference from the "natural" state quite quickly. Climate change impacts such as more frequent and severe floods and droughts will affect the food and water security of many people.
Bangladesh is thought to be one of the most vulnerable countries of the world to climate change and sea level rise (CCSLR). IPCC estimates predict that due to the impact of climate change, sea level in Bangladesh may rise by 14 cm by 2025, 32cm by 2050 and 88 cm by 2100. There are a number of environmental issues and problems that are hindering development of Bangladesh. Salinity is a current problem, which is expected to exacerbate by climate change and sea level rise. Salinity intrusion due to reduction of freshwater flow from upstream, salinization of groundwater and fluctuation of soil salinity are major concern of Bangladesh. Cyclones and tidal surge is adding to the problem. Tidal surge brings in saline water inside the polders in the coastal area. Due to drainage congestion, the area remains waterlogged, increasing the salinity (Abedin, 2010).
Bangladesh in general is highly vulnerable to predicted climate changes that are already occurring and are expected to continue over the next century. Bangladesh is recognized worldwide as one of the most vulnerable to the impact of global warming and climate change.
Impacts of Climate Change in Coastal Aquaculture in Bangladeshihn FreeStyle Corp.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average. Climate change may be limited to a specific region, or may occur across the whole Earth. Climate change may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming”. Climate change has both direct and indirect impacts on fish stocks which are exploited commercially. Direct effects act on physiology and behavior and alter growth, reproductive capacity, mortality and distribution. Indirect effects alter the productivity, structure and composition of the marine ecosystems on which fish depend for food. However, even though the year-on-year rate of anthropogenic climate change may seem slow, this is very rapid compared with previous natural change and the accumulative value produces a significant difference from the "natural" state quite quickly. Climate change impacts such as more frequent and severe floods and droughts will affect the food and water security of many people.
Bangladesh is thought to be one of the most vulnerable countries of the world to climate change and sea level rise (CCSLR). IPCC estimates predict that due to the impact of climate change, sea level in Bangladesh may rise by 14 cm by 2025, 32cm by 2050 and 88 cm by 2100. There are a number of environmental issues and problems that are hindering development of Bangladesh. Salinity is a current problem, which is expected to exacerbate by climate change and sea level rise. Salinity intrusion due to reduction of freshwater flow from upstream, salinization of groundwater and fluctuation of soil salinity are major concern of Bangladesh. Cyclones and tidal surge is adding to the problem. Tidal surge brings in saline water inside the polders in the coastal area. Due to drainage congestion, the area remains waterlogged, increasing the salinity (Abedin, 2010).
Bangladesh in general is highly vulnerable to predicted climate changes that are already occurring and are expected to continue over the next century. Bangladesh is recognized worldwide as one of the most vulnerable to the impact of global warming and climate change.
Marine Resources: Physical and biological resources, marine energyihn FreeStyle Corp.
Marine resources are physical and biological entities that are found in seas and oceans that are beneficial to man. They include fish, coral reefs and crabs, fungi, etc. A lot of conservation effort is required to protect these resources from human destruction activities like pollution and over fishing. Marine natural resources include both biological and physical sources. Biological sources include anything attributed to life forms whereas physical sources are considered to be those things that are not part of life processes. In a few instances some resources are both biological and physical. In considering the outlook of our oceans it is important to first identify the main natural resources and their status.
A rice-fish system is an integrated rice field or rice field/pond complex, where fish are grown concurrently or alternately with rice. Fish may be deliberately stocked (fish culture), or may enter fields naturally from surrounding water ways when flooding occurs (rice field fisheries), or a bit of both. Fish yields can range widely from of 1.5 to 174 kg/ha/season depending on the type of rice fish system, the species present, and the management employed.
In a country like Bangladesh where land is scarce, effort should be taken to increase production through integration of various production system like animal-cum-fish or rice-cum-fish culture for efficient utilization of available meagre resources and maximization of production of diversified products, from a minimum area, which will increase the income of the farmers and would enhance food production. A multi-commodity farming system presents more advantages to a mono-cropping system. But the commodity-integration must fit into the particular farmer's capability, resources and need as well as the social, economic and environmental factors around him.
Goat cum Fish Farming - Present Status and Prospect in Bangladeshihn FreeStyle Corp.
In a country like Bangladesh where land is scarce, effort should be taken to increase production through integration of various production system like animal-cum-fish or rice-cum-fish culture for efficient utilization of available meagre resources and maximization of production of diversified products, from a minimum area, which will increase the income of the farmers and would enhance food production. A multi-commodity farming system presents more advantages to a mono-cropping system. But the commodity-integration must fit into the particular farmer's capability, resources and need as well as the social, economic and environmental factors around him.
Growth Performance of Catla (Catla catla) Fed Diets Containing Different Leve...ihn FreeStyle Corp.
Carp culture has attained commercial culture status.
Feed has become the most important component.
Fish meal induce good growth but it is expensive.
Due to the scarcity of fish meal ; alternative protein sources is gaining importance.
Spirulina platensis (blue green algae) ; A Cyanobacterium.
Spirulina as the replacement of fish meal.
How to write a project proposal ? (*For bd students only)ihn FreeStyle Corp.
Stinging catfish (Heteropneustes fossilis) is one of the commercially farmed fish in Bangladesh and it has gained rapid popularity because of its fast growth and high yields. The species is important for its nutritional and medicinal value. However, the absence of a readily available starter feed in commercial hatcheries remains a major problem in its production. Fish larvae rely on the yolk sac for its nutritional requirements during early stages of growth. Then larvae require live foods such as Artemia nauplii, yeast, unicellular algae, rotifers, copepods, cladocerans as the most appropriate starter foods because the larvae have difficulty in assimilating dry prepared diets due to their incomplete development of the digestive system (Arimoro, 2006; Olurin et al. 2012). These live foods offer an appropriate size ingestible by a wide range of larval fish species and are rich carriers of digestive enzymes (Kolkvoski, 2001). Live foods also affect the fatty acid profile of larvae (Kainz, 2004; Das, 2006; Tocher, 2010). However, information on appropriate live foods for the larviculture of stinging catfish are scarcely available.
What is the stocking density of fish in semi intensive cultureihn FreeStyle Corp.
Stocking Density: Stocking density also known as per-unit stocking amount or stocking rate, refers to the quantity of fry or fingerlings per unit of water area.
Poly Culture: The concept of poly culture of fish is based on the concept of total utilization of different trophic and spatial niches of a pond in order to obtain maximum fish production per unit area. Different compatible species of fish of different trophic and spatial niches are raised together in the same pond to utilize all sorts of natural food available in the pond.
Semi Intensive Culture: Semi-intensive culture systems depend largely on natural food which is increased over baseline levels by fertilization and/or use of supplementary feed to complement natural food.
The increased production of marine fish has come primarily through the motorization of traditional craft, the introduction of new craft and the introduction and popularization of new’ types of synthetic gear, which have replaced the traditional gear. In almost every country, this process has been either instituted or actively supported by the governments in the form of generous subsidies and credit schemes. Blue Economy could play an important role in the economic upliftment of the country in the context of poverty alleviation, ensuring food and nutrition security, combating climate change impacts. Blue Economy requires a balanced approach between conservation, development and utilization of marine and coastal eco-systems, all oceanic resources and services with a view to enhancing their value and generates decent employment, secure productive marine economy and healthy marine eco-systems.
Fisheries and aquatic resources are economically, ecologically, culturally and aesthetically important to the nation. From the global perspectives, the main issues facing by the international fishing community generally are over fishing, overcapacity, by-catch management as well as environmental degradation. The combined effect of these factors that have made 60-70% of the major world fisheries resources are in urgent need of management action to restrict the increase in fishing capacity and to rehabilitate damaged resources (FAO,1991). In Bangladesh, fisheries is one of the major subsectors of agriculture, which play a dominant role in nutrition, employment, earning foreign currency and other areas of economy. Many of our open waterbody are polluted with various pollutants and harmful chemicals. Water Resources Planning Organization (WARPO) has prepared the National Water Management Plan (NWMP) for Bangladesh in December 2001. The goal of the NWMP is to implement the National Water Policy (NWPo) and contribute to national economic development through rational management of open water resources, in a way that protects the natural environment and improves the quality of life for the people of Bangladesh. Open water fisheries are major aquatic common property resources in Bangladesh covering over four million hectares. Around ten percent of the population of 120 million depend for their livelihoods on fisheries.
Hygiene standards and procedures usually described as Good Hygienic Practices (GHP) or Good Manufacturing Practices (GMP), have been in place for many years and constituted an essential tool in traditional food control. These concepts are still essential in a modern food control system by providing the basic environmental and operating conditions for production of safe food and thus being a requisite or foundation for HACCP in an overall food safety management program. What is new is the concept of formalizing the prerequisite program alongside HACCP and the legal requirement in some countries (USA) of documented monitoring of certain sanitation areas.
Non-Infectious Disease
Not caused by pathogens
Cannot be transmitted to other species
Malnutrition, Avitaminoses, Heavy Metals etc. are responsible
Risk factors:
Genetics
Life-style
Environmental factors
Genetic Risk Factors
Determined by genes
Familial Disease Tendency
Disease runs in species
Recessive gene disorders
Down syndrome
Born with extra chromosome
Sex-linked disorders
Linked to x chromosome (female)
Can be recessive in females
Color blindness, hemophilia, & muscular dystrophy
A popular food fish in South Asia. Five types of ilish can be found worldwide.
Yearly ilish caught are 5,000,000 tons. Among them, 50%-60% are caught by Bangladesh.
About 450,000 people are directly involved with the catching for livelihood; around four to five million people are indirectly involved with the trade.
Ideally, surimi should be made from low-value, white-fleshed fish with excellent gelling ability and which are abundant and available year-round. At present, Alaskan pollack accounts for a large proportion of the surimi supply. Other species, such as sardine, mackerel, barracuda, striped mullet have been successfully used for surimi production.
Any aquatic invertebrate animals having a cutaneous or calcareous shell surrounding there body and belonging to the phylum Mollusca, the class Crustacea (phylum Arthropoda), or phylum Echinodermata is known as shellfish. The term is often used for the edible species of the groups, especially those that are fished or raised commercially. The most commercially important shellfish are:
• Mollusk: Oysters, mussels, scallops and clams
• Crustacean: Shrimp, prawn, lobster, crab and crayfish
• Echinoderm: sea urchins and sea cucumbers
Shellfish hatchery is a place where shellfish seeds are produced in a controlled way. Hatchery management is a branch of science which deals with the activities including from collection of brood shellfish to seed production. Culturing of shellfish has occurred since ancient times. Although controlled rearing of young shell has long existed, hatchery production is a more recent advancement. Producing seed under controlled conditions in a hatchery will disconnect its production from environmental factors and provide a reliable supply of seed. Oysters, mussels and mud crabs are the most important groups of shellfish after shrimp and prawn. These are popular among the western countries and becoming more popular all over the world. So hatchery management of oyster, mussel and crab is crucial.
The homeotherms are otherwise known as warm blooded animals. Their body temperature remains constant irrespective of change in environmental temperature e.g. birds and mammals. The poikilotherms are otherwise known as cold blooded animals. Their body temperature fluctuates according to change of the temperature in the surroundings e.g. fishes, amphibians, reptiles and invertebrates.
Transport of hatchlings, fry and fingerlings of culturable species is a common necessity in aquaculture. Generally the fry trading season starts in April and continues until the end of September in Bangladesh. Nevertheless, mortality is the major problem of our traditional transportation system of fish fry. In Bangladesh, fish seed production hatcheries are typically situated far away from fish rearing ponds. I went to jessore to purchase 2kg fish seed. I bought 2kg fish seed from kappothakko nod hatchery in Jessore. The distance of Jessore to Gazipur is approximately 242 km away.The price of fish seed is 2000 to 3000Tk in case of Indian major carp.I have bought 2kg fish seed from Jessore to Gazipur by pick up. Approximately 2kg fish seed contain 7to 8 lac fry.The traditional fish seed transportation methods result in heavy mortality due to accumulation of toxic wastes such as ammonia, decrease in pH due to increase of carbon dioxide (pCO2), depletion of oxygen in the water, thermal tolerance hyperactivity, stress and tiredness of the fry and infection contracted during transportation.
Rotifer any of the members of Rotifera, a minor phylum of animal kingdom composed of microscopic multicellar organisms recognizable by an anterior ciliary organ, known as corona. These minute organisms, also known as wheel animalcule, are principally inhabitants of freshwater bodies, though occasionally reported from salt water, and moist terrestrial habitats. These interesting animals constitute most important food item for the fishes. Zooplankton plays an vital role in the food chain of fish as animal food, which supply amino acids, fatty acids, vitamins, minerals, etc. (Watanabe et al., 1983). In spite of different efforts to replace live food by inert feeds, the rearing of fry and juvenile of fishes (specially zooplankton feeder) in nursery ponds mostly depend on the greater abundance of zooplankton (Habib et al., 1988).
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Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
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June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
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The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
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The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
1. 1 | P a g e
Use of Rotifer in Aquaculture of Bangladesh
Introduction
Rotifers are popularly called as wheel animalcules. They are an important group of live food
organisms for use in aqua hatcheries. Brachionus, which is the most known form of all rotifers,
serve as an ideal starter diet for early larval stages of many fish and prawn species in marine as
well as freshwater. Species of the genus Brachionus (Brachionidae: Rotifera) are well represented
in different water bodies worldwide (Pejler, 1977). Depending on the mouth size of the cultured
organisms, small (50 to 110 micron length) or large (100 to 200 micron length) rotifers are used.
There are about 2,500 species of rotifers have been known from global freshwater, brackish water,
and seawater. B. plicatilis is the species used most commonly to feed fish larvae in hatcheries
around the world. It is a euryhaline species, small and slow swimming, with good nutritional value.
It is well suited to mass culture because it is prolific and tolerates a wide variety of environmental
conditions. The rotifer, B. plicatilis and B. rotundiformis, have been indispensable as a live food
for mass larval rearing of many aquatic organisms (Maruyama et al., 1997). By way of significant
developments in larval rearing technology of fishes, demand for the rotifer is further increasing.
Aquaculture
Aquaculture, probably the fastest growing food-producing sector, now accounts for nearly 50
percent of the world's food fish. The need to exchange reliable information on all related subjects
is becoming a key issue for the responsible management of aquaculture. FAO (1988) introduced a
definition of aquaculture, which reduces its confusion with capture fisheries: “Aquaculture is the
farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants. Farming
implies some form of intervention in the rearing process to enhance production, such as regular
stocking, feeding, protection from predators, etc. Farming also implies individual or corporate
ownership of the stock being cultivated. For statistical purposes, aquatic organisms which are
harvested by an individual or corporate body which has owned them throughout their rearing
period contribute to aquaculture, while aquatic organisms which are exploitable by the public as a
common property resources, with or without appropriate licenses, are the harvest of fisheries”.
Aquaculture in Bangladesh
Bangladesh is a densely populated country of 147 570 square km with a population of 130 million
people. It is fortunate in having an extensive water resource in the form of ponds, natural
depressions (haors and beels ), lakes, canals, rivers and estuaries covering an area of 4.56 million
ha(DoF,2005).
Bangladesh is one of the world's leading inland fisheries producer with a production of 1 646 819
tons during 2003–4, with marine catch total of 455 601 tons and a total production from
aquaculture of 914 752 tons during 2003–4. Bangladesh's total fish production for the year totaled
above 2.1 million tons (DoF, 2005). FAO (2005) ranked Bangladesh as sixth largest aquaculture
producing country with its estimated production of 856 956 tons in 2003 (FAO, 2005).
Aquaculture accounted for about 43.5 percent of the total fish production during 2003–4, with
inland open water fisheries contributed 34.8 percent (DoF, 2005).
2. 2 | P a g e
The present per capita annual fish consumption in Bangladesh stands at about 14 kg/year against
a recommended minimum requirement of 18 kg/year; hence, there is still need to improve fish
consumption in the country.
Fisheries in Bangladesh are diverse; there are about 795 native species of fish and shrimp in the
fresh and marine waters of Bangladesh and 12 exotic species that have been introduced. In
addition, there are 10 species of pearl bearing bivalves, 12 species of edible tortoise and turtle,
15 species of crab and 3 species of lobster.
The Ministry of Fisheries and Livestock (MoFL), Department of Fisheries (DoF), Bangladesh
Fisheries Development Corporation (BFDC) and the Bangladesh Fisheries Research Institute
(BFRI) are the main organizations responsible for aquaculture and its development. Universities,
organizations within other ministries and local and international NGOs are also involved in this
area.
Present Status of Aquaculture in Bangladesh
The country’s fish production has nearly doubled over the last decade—thanks to popularity of
fish farming. According to data of Bangladesh Department of Fisheries, farmed fish production
was 2 million tons in 2013-14. This was only 0.8 million tons back in 2001-02.Consequently, the
overall fish production increased spectacularly by around 88 percent during this period. This is
great news for the nation as fish accounts for about 56 percent of Bangladesh’s intake of animal
protein. According to fisheries department, the country produced about 3.5 million tons of fish in
the 2013-14. Of this, 2.9 million tons came from farms and catches from various Inland water
sources, and 0.6 million tons were from the sea. A decade back, the total fish production stood at
1.9 million tons—majority of it came from various inland water sources.
3. 3 | P a g e
This rise in fish culture is due to increase in high quality fish feed and seed production, and
widespread induced breeding technology, the department says. Another reason that boosted fish
production is the Jatka Conservation project that imposed a ban on Hilsa fishing.
The most dominant source of fresh water fish in the country is the several thousand ponds in the
villages, comprising of about 0.4 million hectare area that produce half of the Inland water fish.
One-quarter fish comes from flood plains.
Water area for Inland fisheries comprises of approximately 4.7 million hectares across the country.
Dhaka division tops fish production with claiming 28 percent of the stake; followed by Chittagong,
Khulna and Rajshahi ranging between 13 percent and 20 percent. Rangpur contributes the least
with just 5 percent production.
As per the Food and Agriculture Organisation (FAO), global fish production was 158 million tons
in 2012 and per capita fish consumption was 19.2 kg. Annual consumption of fish and fish products
in Bangladesh was 12 kg/per person in 2010, with Chittagong having highest annual consumption
of about 17 kg/per person. In Bangladesh, about three fourth of consumed fish are fresh water fish,
among which Pangas, Rui, and Tilapi tops our chart. Pangas farming has become an established
agro-processing industry in the country over the last decade. Pangas is most easy to produce due
to its short culture-cycle, high growth rate and unselective feeding habit. It also has good resistance
to diseases. These characteristics are somewhat also present in Tilapia.
4. 4 | P a g e
Export of fish and fish products increased by 86 percent from 2001-02 and reached 77,000 tons in
2013-14.
Rotifers in Bangladesh
Many species of rotifers have been identified from different types of freshwater bodies in
Bangladesh. Brachionid rotifers seem to be predominant and the common species recorded are
Brachionus diversicornis, B. falcatus, B. quadridentatus, B. calyciflorus, B. havanensis and B.
forficula. The other common genera in Bangladesh are Keratella, Monostyla, Lecane, Lepadella,
Filinia, Trichocerca, Polyarthra, etc.
Importance of Rotifers
As a live food, rotifers are the perfect size (105-160 micrometers in width) for many species of
fish larvae that are cultured commonly. For rotifers to be nutritionally suitable for fish larvae, they
must be "enriched", fed with various combinations of microalgae or commercially prepared
products. Once enriched, rotifers are an excellent hatchery food for many species of larval fish.
The nutritional value of rotifers for larval fish depends on the rotifers' food source. Researchers
have determined that highly unsaturated fatty acids (HUFAs) are essential for the survival and
growth of finfish larvae. Rotifer feeds containing DHA, 22:6n-3, docosahexaenoic acid, and EPA,
20:5n-3, eicosapentaenoic acid, can be valuable, with DHA the more essential for marine fish
larvae. Depending upon their food source, rotifers are about 52 to 59 percent protein, up to 13
percent fat, and 3.1 percent n-3 HUFA.
Biology and Life History
The life span of rotifers has been estimated to be between 3.4 to 4.4 days at 25°C. Generally, the
larvae become adult after 0.5 to 1.5 days and females thereafter start to lay eggs approximately
every four hours. It is believed that females can produce ten generations of offspring before they
eventually die.
The life cycle of Brachionus plicatilis can be closed by two modes of reproduction. During female
parthenogenesis the amictic females produce amictic (diploid, 2n chromosomes) eggs which
develop and hatch into amictic females. Under specific environmental conditions the females
switch to a more complicated sexual reproduction resulting in mictic and amictic females.
Although both are not distinguishable morphologically, the mictic females produce haploid (n
chromosomes) eggs. Larvae hatching out of these unfertilized mictic eggs develop into haploid
males. These males are about one quarter of the size of the female; they have no digestive tract
and no bladder but have an over-proportionated single testis which is filled with sperm. Mictic
eggs which will hatch into males are significantly smaller in size, while the mictic fertilized eggs
are larger and have a thick, faintly granulated outer layer.
5. 5 | P a g e
Figure 1. Parthenogenetical and sexual reproduction in Brachionus plicatilis (modified from Hoff and
Snell, 1987).
These are the resting eggs that will only develop and hatch into amictic females after exposure to
specific environmental conditions. These can be the result of changes in environmental conditions
eventually creating alternations in temperature or salinity or changing food conditions. It should
be emphasized that the rotifer density of the population also plays an important role in the
determination of the mode of reproduction. Although the mechanism is not completely understood,
it is generally believed that the production of resting eggs is a survival strategy of the population
through unfavorable environmental conditions such as drought or cold.
6. 6 | P a g e
Strain Differences
Only a few rotifer species belonging to the genus Brachionus are used in aquaculture. Brachionus
plicatilis is a cosmopolitan inhabitant of inland saline and coastal brackish waters. It has a lorica
length of 100 to 340 mm, with the lorica ending with 6 occipital spines.
However, for use in aquaculture, however, a
simple classification is used which is based on
two different morphotypes, namely Brachionus
rotundiformis or small (S-type) rotifers
and Brachionus plicatilis or large (L-type)
rotifers. The differences among the two types
can be clearly distinguished by their
morphological characteristics: the lorica length
of the L-type ranging from 130 to 340 mm
(average 239 mm), and of the S-type ranging
from 100 to 210 mm (average 160 mm).
Moreover, the lorica of the S-type shows
pointed spines, while of the L-type has obtuse
angled spines.
Figure 2 : Brachionus rotundiformis (S-type) and Brachionus plicatilis (L-type) (modified from
Fu et al., 1991).
Who uses rotifers?
Rotifer is used in-
• Finfish hatcheries
• Ornamental fish breeders
• Shrimp hatcheries
Uses of Rotifer in Larviculture
The successful use of rotifer in commercial hatchery operations of red sea beam (Pargus major)
encouraged investigations in the development of mass culture techniques of rotifer. Twenty years
ago, rotifer was first used in larviculture feeding. Fingerling production is one of the many
challenges faced by those interested in promoting industrial production of emerging marine and
fresh water species. In spite of huge efforts to use artificial feeds, the of fish larvae during the
primary nursing phase still depends heavily on natural food. Live feeds include Rotifers, Artemia
and other tiny organisms are often the enhancing larval production. These live foods are used in
larviculture of carps, catfish and shrimp. Though there is not enough study on rotifer culture in
Bangladesh. The benefits they are getting is discussed below.
7. 7 | P a g e
Brachionus plicatilis
B. plicatilis is the species used most commonly to feed larval fish in hatcheries in Bangladesh. It
is a euryhaline species, small and slow swimming, with good nutritional value. It is well suited to
mass culture because it is prolific and tolerates a wide variety of environmental conditions.
Brachionus calyciflorus
The freshwater rotifer B. calyciflorus is widely used in aquaculture as a live food to raise larvae of
many species during the first two weeks of exogenous feeding. No other live food has been developed
for larval feeding that can replace rotifers. The two types of protease enzymes in rotifers assist fish
larvae to digest them. Weight, rearing environment and feeding protocol are among the key factors
affecting the migration and fishery returns of fish fingerlings produced by artificial breeding programs
for the purpose of restocking and rehabilitation of stocks.
Brachionus angularis
Brachionus angularis is a cosmopolitan freshwater rotifer. Its potential use as live food for small-
mouthed freshwater fish larvae. In the past, there was less demand for small live food in freshwater
aquaculture, but the demand in recent years has been increasing for several reasons. Ornamental
freshwater fishes that produce small larvae which require small planktonic rotifers for fry
production. This rotifer is used in Bangladesh for Larvae culture.
Now, In Bangladesh; Different hatchery owners prefer different rotifer spp. For feeding their
freshwater larvae. Sometimes they use rotifer as live capsule by enriching rotifer with different
nutrient. As rotifer is a highly nutritive for freshwater fish larvae, hatchery owners of Bangladesh
are used this for better survival of fish larvae.
Uses in Catfish
Larval nutrition and live feed culture like Artemia and rotifers is one of the most important and
obligatory matter for successful fish culture. Feeding with live prey for fish larvae are most
essential because during first few days of their life they have no complete develop digestive tract,
especially their digestive enzymes. Moreover, live increases feeding by predatory larvae, resulting
reduce cannibalism of some species like Clarius gariepinus the enhancing larval production.
Clarius gariepinus is generally considered as predator or omnivorous and also commercially
important fish for aquaculture because they are able to tolerate to extreme environment conditions
and worldwide demand. Awaiss and Kestemont studied the suitability of the freshwater rotifer
Brachionus calyciflorus as starting food for the larviculture of African catfish. Rotifer also acts as
an important food for stinging catfish Heteropnuestes fossilis in their early larval stage of life.
Uses in Shrimp Culture
Now-a-days rotifers are used as replacement of Artemia in shrimp culture. In some coastal shrimp
hatcheries of Bangladesh rotifers are used as successful larvae feed. Many marine fish hatcheries
incorporate rotifers in their larval diets because rotifers are smaller than Artemia. With shrimp,
8. 8 | P a g e
Artemia is usually introduced in the Mysis stage, but most species can survive on rotifers from
earlier stages. The success of extensive penaeid larvae rearing systems using rotifers in areas where
Artemia and enrichment diets are prohibitively expensive or unavailable indicates that they are an
alternative worth considering.
Producers of Rotifers
Hatcheries equipped with modern facilities produce rotifers for their culture operations to prevent
mass mortality of species that fetch high market value. The larval stages of stinging catfish
popularly known as shing and African catfish are very sensitive. Therefore, culture operation of
these two species is not easy because of appropriate feed. Live feed like Artemia and rotifer can
overcome the problem. Bangladesh Fisheries Research Institute (BFRI) and live feed laboratories
from different public universities are aiming to disseminate the effective and efficient technique
of culturing rotifers and other live feed organisms.
Problems associated with Rotifer Culture
The culture of rotifer needs intensive care and the environment should be friendly. Inexperienced
personnel can ruin up the whole operation. Therefore, they need to be trained up to run the culture
successfully. There is another problem concerning rotifer culture. Food of rotifer is important.
They feed on phytoplankton like Chlorella sp. Before setting up rotifer culture, farm owners
should consider set up phytoplankton culture. And establishment of advanced live food laboratory
is essential.
Prospects of Rotifer Culture in Bangladesh
Artemia is widely used in different hatcheries across Bangladesh. If there is any 2nd choice that is
rotifer. Bangladesh is a culture based fish producing country. The environment exists here is
suitable for rotifer culture. To produce huge number of fish fry, live food like rotifer is essential to
provide balanced nutrition in their larval stage and prevent mass mortality.
Conclusion
There are about 2000 rotifer species all requiring moisture and most of them inhabit freshwater
(around 1950 species). Most rotifers are free swimming and form an important part of the
freshwater zooplankton. This types of Rotifers are highly nutritive food for larvae culture. So, we
need to put great emphasize for rotifer culture in Bangladesh. Then we can make more profit in
aquaculture.
9. 9 | P a g e
References
Pejler, B., 1977. On the global distribution of the family Brachionidae (Rotifera). Arch. Hydrobiol.
Suppl., 53: 255–307.
Maruyama, I., Nakao, T., Shigeno, I., Ando, Y., Hirayama, K., 1997. Application of unicellular
algae Chlorella vulgaris for the mass culture of marine rotifer Brachionus. Hydrobiologia, 358:
133-138.