This document summarizes the reproductive biology of the flathead grey mullet (Mugil cephalus). Key points include:
- M. cephalus spawns in marine waters from late January to February after migrating from estuaries for spawning.
- Maturity is reached at 16cm length. Gonad development peaks from October to January as indicated by increasing gonadosomatic index values.
- Fecundity ranges from 0.4 to 8.2 million eggs depending on size, with larger fish producing more eggs.
- Sex ratio in spawning stocks favors males at 1.99:1.
This document provides information on oyster and mussel culture techniques. It discusses the importance of shellfish aquaculture for food production and livelihoods. Oyster culture techniques are described in detail, including the biology and life cycle of oysters, breeding habits, larval development, setting behaviors, and environmental factors like food sources, predators, and fouling organisms that affect oyster farms. The objective is to understand different culture methods for farming oysters and mussels commercially.
This document provides information on 11 species of catfish from 7 families. It discusses their classification, distribution, biology, culture practices, and production. Some of the main points covered include:
- Channel catfish, African sharptooth catfish, and river catfish are among the most commercially important species.
- Catfish are farmed using cages, ponds and pens. They grow quickly and can be raised at high densities, yielding 6-10 tons/ha/year.
- Major producers include Vietnam, China, USA, Nigeria, and Bangladesh. Vietnam is the world's largest producer of catfish, yielding over 1.1 million tons in 2010 for export.
The document discusses various models and methods commonly used for marine fish stock assessment. It provides an overview of holistic or surplus production models, which analyze the relationship between effort and catch to estimate biomass and fishing mortality. Yield or yield per recruit models compute yield given exploitation patterns at different effort intensities. Virtual population analysis and cohort analysis reconstruct stock histories from catch-at-age data. Length cohort analysis is a modification of VPA that can use length frequency distributions. Time series analysis examines trends, seasonality and noise in catch or effort time series data. Ecological models account for biological interactions between species, while simulation modeling tests management actions and environmental impacts. Worked examples demonstrate length cohort analysis and yield per recruit modeling.
Nutritional requirement of larvae and broodstock of commercially important fi...Akhila S
the presentation provides the details regarding, Tthe broodstock nutrition, essential nutrients and recent data on broodstock nutrition; also larval nutrition; the hatchery utilised live feeds in detail and also microparticulate diet, the recent knowlwdge on essential elements amd minerals in larval nutrition, like taurine, phospholipids, liposomes, waxy spray beds etc
This document provides an introduction to fish stock assessment and key concepts. It discusses the primary objective of fish stock assessment as determining the optimal exploitation level to achieve maximum sustainable yield. It defines the stock concept as a subset of a species inhabiting a particular area with consistent growth and mortality parameters. The document emphasizes that fish stock assessment should be performed separately for each identified stock.
This document discusses the culture methods for the rotifer Brachionus plicatilis, an important live feed for larval marine animals. It describes how to maintain stock cultures in 1-2L flasks using Isochrysis galbana algae at 24-25C under a 12:12 light cycle. Main culture methods discussed are using various tank sizes from 50L to 1800L, sterilizing tanks with bleach, and maintaining temperature at 24-26C with lighting. Feeding protocols are provided using yeast, fish oil, and algae to culture rotifers from low to high densities. Rotifers are harvested daily and fed to larval fish starting at 3 days post hatch at 3
Reservoirs in India hold potential for inland fisheries development but currently contribute less than expected to fish production. There are over 19,000 reservoirs in India covering 3.15 million hectares. The average fish yield from reservoirs is around 20 kg/ha but could be increased to 250 kg/ha through management. Key factors influencing reservoir productivity include morphometric characteristics, climate, soil properties, and chemical stratification. Management approaches for reservoirs focus on stock enhancement, species enhancement, and environmental enhancement through stocking of suitable fish species and regulating fishing efforts.
Alimentary canal and feeding adaptations in fishes by nusritSYED ASSIM HAQ
The document discusses the alimentary canal and feeding adaptations in fishes, describing the different regions and structures of the canal from mouth to rectum and how they vary based on a fish's feeding habits, such as differences in teeth, gill rakers, stomach, and intestinal length between carnivorous, herbivorous, and omnivorous fish. It also covers the digestive glands and enzymes involved in digestion as well as various adaptations that have evolved in fishes' structures to suit their natural diets.
This document provides information on oyster and mussel culture techniques. It discusses the importance of shellfish aquaculture for food production and livelihoods. Oyster culture techniques are described in detail, including the biology and life cycle of oysters, breeding habits, larval development, setting behaviors, and environmental factors like food sources, predators, and fouling organisms that affect oyster farms. The objective is to understand different culture methods for farming oysters and mussels commercially.
This document provides information on 11 species of catfish from 7 families. It discusses their classification, distribution, biology, culture practices, and production. Some of the main points covered include:
- Channel catfish, African sharptooth catfish, and river catfish are among the most commercially important species.
- Catfish are farmed using cages, ponds and pens. They grow quickly and can be raised at high densities, yielding 6-10 tons/ha/year.
- Major producers include Vietnam, China, USA, Nigeria, and Bangladesh. Vietnam is the world's largest producer of catfish, yielding over 1.1 million tons in 2010 for export.
The document discusses various models and methods commonly used for marine fish stock assessment. It provides an overview of holistic or surplus production models, which analyze the relationship between effort and catch to estimate biomass and fishing mortality. Yield or yield per recruit models compute yield given exploitation patterns at different effort intensities. Virtual population analysis and cohort analysis reconstruct stock histories from catch-at-age data. Length cohort analysis is a modification of VPA that can use length frequency distributions. Time series analysis examines trends, seasonality and noise in catch or effort time series data. Ecological models account for biological interactions between species, while simulation modeling tests management actions and environmental impacts. Worked examples demonstrate length cohort analysis and yield per recruit modeling.
Nutritional requirement of larvae and broodstock of commercially important fi...Akhila S
the presentation provides the details regarding, Tthe broodstock nutrition, essential nutrients and recent data on broodstock nutrition; also larval nutrition; the hatchery utilised live feeds in detail and also microparticulate diet, the recent knowlwdge on essential elements amd minerals in larval nutrition, like taurine, phospholipids, liposomes, waxy spray beds etc
This document provides an introduction to fish stock assessment and key concepts. It discusses the primary objective of fish stock assessment as determining the optimal exploitation level to achieve maximum sustainable yield. It defines the stock concept as a subset of a species inhabiting a particular area with consistent growth and mortality parameters. The document emphasizes that fish stock assessment should be performed separately for each identified stock.
This document discusses the culture methods for the rotifer Brachionus plicatilis, an important live feed for larval marine animals. It describes how to maintain stock cultures in 1-2L flasks using Isochrysis galbana algae at 24-25C under a 12:12 light cycle. Main culture methods discussed are using various tank sizes from 50L to 1800L, sterilizing tanks with bleach, and maintaining temperature at 24-26C with lighting. Feeding protocols are provided using yeast, fish oil, and algae to culture rotifers from low to high densities. Rotifers are harvested daily and fed to larval fish starting at 3 days post hatch at 3
Reservoirs in India hold potential for inland fisheries development but currently contribute less than expected to fish production. There are over 19,000 reservoirs in India covering 3.15 million hectares. The average fish yield from reservoirs is around 20 kg/ha but could be increased to 250 kg/ha through management. Key factors influencing reservoir productivity include morphometric characteristics, climate, soil properties, and chemical stratification. Management approaches for reservoirs focus on stock enhancement, species enhancement, and environmental enhancement through stocking of suitable fish species and regulating fishing efforts.
Alimentary canal and feeding adaptations in fishes by nusritSYED ASSIM HAQ
The document discusses the alimentary canal and feeding adaptations in fishes, describing the different regions and structures of the canal from mouth to rectum and how they vary based on a fish's feeding habits, such as differences in teeth, gill rakers, stomach, and intestinal length between carnivorous, herbivorous, and omnivorous fish. It also covers the digestive glands and enzymes involved in digestion as well as various adaptations that have evolved in fishes' structures to suit their natural diets.
Fish require energy for various life processes like maintenance, growth, and reproduction. Their metabolic rate depends on water temperature, so they eat more in summer than winter. Energy from food is used for maintenance, activity, tissue synthesis, and other processes. Intake energy from food is partitioned, with some lost in feces, urine, gills, and scales, while metabolizable energy is available for metabolic processes and retained energy is stored or used to produce gametes. Factors like body size, oxygen availability, temperature, osmoregulation, and stress impact how energy from food is partitioned in fish.
This document defines aquaculture as the farming of aquatic organisms such as fish, mollusks, crustaceans, and aquatic plants. It involves interventions like regular stocking, feeding, and protection from predators to enhance production. India has a long coastline and extensive water resources that are well suited for aquaculture. The purpose of aquaculture includes increasing food production and income, as well as generating employment. There are various types of aquaculture defined by factors like the water system used, type of water, stocking combinations, and integration with other farming systems.
To identify fish species, measurements, counts of anatomical features, and color patterns are used. Meristic traits involve counting scales, fins, spines, and soft rays. Morphometric traits involve measuring features like standard length, head length, and fin lengths relative to standard length. To identify an unknown fish, samples are collected and their meristic traits like scale counts and fin formulas are recorded, along with morphometric trait measurements, which are then compared to published identification standards.
The document provides information about the mud crab (Scylla serrata), including its classification, distribution, ecology, and methods for farming and hatchery management. It notes that mud crabs are found naturally in the Indo-Pacific region and are an economically important species. Mud crab farming can be done using grow-out systems, where young crabs are raised for 5-6 months until market size, or fattening systems, where soft-shelled crabs are raised for a shorter period. Hatchery management involves broodstock selection and care, spawning and larval rearing techniques, and achieving survival rates as high as 18.1% compared to the world average of 3-3.5
This document discusses cold water fisheries in India. It describes the temperature range for cold water fisheries (5-25°C) and notes that states like Kashmir, Himachal Pradesh, and Uttarakhand are well-suited for cold water fisheries. It identifies important cold water fish species in India like various types of mahseer and trout. Mahseer can grow up to 1.5 meters long and breed from July to September. Trout generally feed on other fish and aquatic invertebrates. Cold water fisheries provide income, employment, and food for local populations and have significant potential to contribute to India's fisheries sector and economy.
This document presents different culture methods for farming mussels. There are three main types of culture methods: bottom culture, intertidal and shallow water culture, and deep water culture. Intertidal and shallow water culture methods include rack culture, tray culture, wig-wam culture, and rope-web culture. Rack culture involves hanging mussel collectors on bamboo poles. Tray culture uses bamboo or metal trays suspended on poles. Deep water culture methods are raft culture, using rafts to hold suspended rope collectors, and long-line culture, which uses underwater lines anchored at the bottom.
1. There are three types of reservoirs in India - small (<1000 hectares), medium (1000-5000 hectares), and large (>5000 hectares). Small reservoirs account for the largest number (19,134) and area (1.48 million hectares).
2. Indian reservoirs tend to be nutrient-rich with narrow temperature fluctuations that prevent thermal stratification in many areas. Biotic communities include phytoplankton, zooplankton, fish, and decomposers like bacteria and fungi.
3. Fish production in Indian reservoirs is low on average at 20 kg/ha compared to potential yields, with room for improvement through management practices like stocking preferred fish species.
Finfish breeding and hatchery management pdfKartik Mondal
Rivers were the major source of freshwater fish seed in India during 1950’s and 1960’s.
Over the years, the riverine contribution has declined and at present forms only a supplementary source, constituting less than 5% of the country’s total fish seed production.
The Ganga, the Brahmaputra and the Indus river systems in the North and the Peninsular East coast and the West coast river systems in the South are the important natural sources of fish seed.
Cage culture involves raising fish in mesh boxes placed in bodies of water. It originated in Cambodia about 200 years ago when cages were used to transport live fish to market. Cages are constructed with frames made of wood, plastic or steel, with floats to keep them buoyant and weights to anchor them. They come in various shapes and sizes, usually square or rectangular, and are 20-60 cubic meters. Cages are either fixed in flowing water, floating in lakes/rivers/offshore, or submerged and movable in areas prone to cyclones. Fish are fed through natural water movement and supplemental feeding of rice bran, fish meal and soybean cake. Fish production ranges from 3,000-25,000 kg
The cold water fisheries deal with fisheries activity in water where temperature of water ranges from 5 to 25 degrees centigrade. The water temperature under cold water fisheries should not be more than 25°C even in summer. Such conditions in India occur in Himalayan and peninsular regions.
9 Finest Coldwater Aquarium Fish
Orangethroat Darter.
Three-Spined Stickleback.
Orange-Spotted Sunfish.
Diamond Sturgeon.
Siberian Sturgeon.
Sterlet.
Fathead Minnow.
Southern redbelly dace.
Tench.
Rosy Barb. Hailing from Afghanistan and Bangladesh, this little fish is tolerant of temperatures in …
Gold Barb. The gold bard, or Chinese barb, is an extremely popular cold-water fish. Any aquarium …
Two Spot Barb. This fish hails from Nepal, India, and Pakistan. The omnivorous two spot barb …
Bloodfin Tetra. Natives to Southern Brazil and Paraguay, both the standard bloodfin .
Coldwater fish in terms of the aquarium trade refers to any fish species that prefer cooler water temperatures. The optimal temperatures for these fish hover around the 68-degree mark, although each species’ temperature range may vary from the norm.
This document provides information on lobster culture and its management. It discusses the important lobster species for culture, their habitat and feeding habits. It describes the breeding technology, seed collection methods, and hatchery and nursery management practices. Grow-out can be done using land-based tanks or sea cages. Key water quality parameters and stocking densities are outlined. Finally, common diseases affecting farmed lobsters are identified along with control measures.
Fishes, amphibians, reptiles, and birds have paired pharyngeal ultimobranchial glands that secrete the hypocalcemic hormone calcitonin. The corpuscles of Stannius, unique glandular islets found only in the kidneys of bony fishes, secrete a peptide called hypocalcin.
Present status & future prospects in marine aquacultureKiritKene
This document provides an overview of the present status and future prospects of marine aquaculture in India. It discusses key topics like the major cultivable species, top aquaculture producer countries, present status of marine fisheries resources in India, financial facilities available, and future growth opportunities. The document contains tables and information on aspects like state-wise marine fish production, cultivable biological resources, site selection criteria, and the role of organizations like FAO in supporting the sector.
culture system - semi intensive, intensive, super intensice and cage.pptxHimanshuPatidar19
This document discusses different types of aquaculture systems including semi-intensive, intensive, and super intensive systems. It also discusses different cage culture systems used in aquaculture like fixed cages, floating cages, submersible cages, and submerged cages. Semi-intensive systems involve stocking fish at moderate densities and relying on natural foods supplemented with feed. Intensive systems rely on artificial feeds and management to maximize yields. Super intensive systems involve very high stocking densities and use of water treatment technologies like recirculating aquaculture systems.
This document provides an overview of reproductive biology in fishes. It discusses the different types of sexuality observed in fishes, including unisexuality, bisexuality, hermaphroditism, and parthenogenesis. It describes the reproductive cycles and hormones that regulate reproduction for both male and female fish. Key aspects covered include the gonads, sexual dimorphism, seasonal breeding patterns, and hormonal control of the reproductive system through the CNS-pituitary-gonad axis.
This document discusses estuaries and estuarine fisheries in India. It defines an estuary and notes that India has over 55 estuaries along its eastern and western coasts, totaling approximately 30,000 square kilometers. Several major river systems like the Ganges, Mahanadi, Godavari and Krishna form highly productive estuarine ecosystems. The document examines the fish production and ecology of estuaries like the Hooghly, Krishna, Godavari, Mahanadi, Chilka, Pulicat Lake, and Kerala backwaters. It provides details on fish catches, species diversity, and threats like overfishing in several of India's important estuarine systems.
The document discusses feed conversion ratio (FCR) and its calculation and application in aquaculture and livestock. FCR is calculated as feed given divided by animal weight gain, with no units. A lower FCR indicates higher weight gain from the feed. For dairy cows specifically, feed efficiency is calculated as energy-corrected milk divided by dry matter intake, which can be difficult to obtain on many dairy operations.
This document discusses the feeding habits and nutritional requirements of fish at different life stages. It begins by explaining that fish require energy, amino acids, fatty acids, vitamins, and minerals to sustain life and promote growth. It then discusses the feeding behaviors and nutritional needs of fish larvae, including their underdeveloped digestive systems and reliance on plankton and zooplankton. The document also categorizes different types of food sources for fish and classifies fish based on their dependence on food types and positions in the water column. Specific examples are provided of the feeding behaviors of fish larvae, juveniles, and adults.
Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) ...Sana_haroon
this is my presentation based on research paper title "Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) from the Gulf of Suez, Red Sea, Egypt"
This was written by Amgad M. Shaaban et al., 2018
Which have Impact factor: 1.98
Le diaporama dédié à la culture du milkfish offrira une exploration approfondie des multiples facettes de cette pratique aquacole. En mettant en avant les conditions environnementales optimales, il abordera les techniques de reproduction, les régimes nutritionnels recommandés, ainsi que les défis et avantages inhérents à l'élevage du milkfish. Des visuels graphiques et des images saisissantes seront incorporés pour illustrer de manière vivante le cycle de vie du poisson et dépeindre les installations d'élevage modernes. En parallèle, des données économiques viendront étayer la présentation, mettant en relief l'impact financier de cette activité. L'aspect culturel du milkfish ne sera pas négligé, mettant en lumière son importance dans diverses régions et soulignant son rôle significatif tant sur le plan économique que social. En somme, ce diaporama vise à offrir une compréhension holistique de la culture du milkfish, alliant informations pratiques et perspectives culturelles.
Fish require energy for various life processes like maintenance, growth, and reproduction. Their metabolic rate depends on water temperature, so they eat more in summer than winter. Energy from food is used for maintenance, activity, tissue synthesis, and other processes. Intake energy from food is partitioned, with some lost in feces, urine, gills, and scales, while metabolizable energy is available for metabolic processes and retained energy is stored or used to produce gametes. Factors like body size, oxygen availability, temperature, osmoregulation, and stress impact how energy from food is partitioned in fish.
This document defines aquaculture as the farming of aquatic organisms such as fish, mollusks, crustaceans, and aquatic plants. It involves interventions like regular stocking, feeding, and protection from predators to enhance production. India has a long coastline and extensive water resources that are well suited for aquaculture. The purpose of aquaculture includes increasing food production and income, as well as generating employment. There are various types of aquaculture defined by factors like the water system used, type of water, stocking combinations, and integration with other farming systems.
To identify fish species, measurements, counts of anatomical features, and color patterns are used. Meristic traits involve counting scales, fins, spines, and soft rays. Morphometric traits involve measuring features like standard length, head length, and fin lengths relative to standard length. To identify an unknown fish, samples are collected and their meristic traits like scale counts and fin formulas are recorded, along with morphometric trait measurements, which are then compared to published identification standards.
The document provides information about the mud crab (Scylla serrata), including its classification, distribution, ecology, and methods for farming and hatchery management. It notes that mud crabs are found naturally in the Indo-Pacific region and are an economically important species. Mud crab farming can be done using grow-out systems, where young crabs are raised for 5-6 months until market size, or fattening systems, where soft-shelled crabs are raised for a shorter period. Hatchery management involves broodstock selection and care, spawning and larval rearing techniques, and achieving survival rates as high as 18.1% compared to the world average of 3-3.5
This document discusses cold water fisheries in India. It describes the temperature range for cold water fisheries (5-25°C) and notes that states like Kashmir, Himachal Pradesh, and Uttarakhand are well-suited for cold water fisheries. It identifies important cold water fish species in India like various types of mahseer and trout. Mahseer can grow up to 1.5 meters long and breed from July to September. Trout generally feed on other fish and aquatic invertebrates. Cold water fisheries provide income, employment, and food for local populations and have significant potential to contribute to India's fisheries sector and economy.
This document presents different culture methods for farming mussels. There are three main types of culture methods: bottom culture, intertidal and shallow water culture, and deep water culture. Intertidal and shallow water culture methods include rack culture, tray culture, wig-wam culture, and rope-web culture. Rack culture involves hanging mussel collectors on bamboo poles. Tray culture uses bamboo or metal trays suspended on poles. Deep water culture methods are raft culture, using rafts to hold suspended rope collectors, and long-line culture, which uses underwater lines anchored at the bottom.
1. There are three types of reservoirs in India - small (<1000 hectares), medium (1000-5000 hectares), and large (>5000 hectares). Small reservoirs account for the largest number (19,134) and area (1.48 million hectares).
2. Indian reservoirs tend to be nutrient-rich with narrow temperature fluctuations that prevent thermal stratification in many areas. Biotic communities include phytoplankton, zooplankton, fish, and decomposers like bacteria and fungi.
3. Fish production in Indian reservoirs is low on average at 20 kg/ha compared to potential yields, with room for improvement through management practices like stocking preferred fish species.
Finfish breeding and hatchery management pdfKartik Mondal
Rivers were the major source of freshwater fish seed in India during 1950’s and 1960’s.
Over the years, the riverine contribution has declined and at present forms only a supplementary source, constituting less than 5% of the country’s total fish seed production.
The Ganga, the Brahmaputra and the Indus river systems in the North and the Peninsular East coast and the West coast river systems in the South are the important natural sources of fish seed.
Cage culture involves raising fish in mesh boxes placed in bodies of water. It originated in Cambodia about 200 years ago when cages were used to transport live fish to market. Cages are constructed with frames made of wood, plastic or steel, with floats to keep them buoyant and weights to anchor them. They come in various shapes and sizes, usually square or rectangular, and are 20-60 cubic meters. Cages are either fixed in flowing water, floating in lakes/rivers/offshore, or submerged and movable in areas prone to cyclones. Fish are fed through natural water movement and supplemental feeding of rice bran, fish meal and soybean cake. Fish production ranges from 3,000-25,000 kg
The cold water fisheries deal with fisheries activity in water where temperature of water ranges from 5 to 25 degrees centigrade. The water temperature under cold water fisheries should not be more than 25°C even in summer. Such conditions in India occur in Himalayan and peninsular regions.
9 Finest Coldwater Aquarium Fish
Orangethroat Darter.
Three-Spined Stickleback.
Orange-Spotted Sunfish.
Diamond Sturgeon.
Siberian Sturgeon.
Sterlet.
Fathead Minnow.
Southern redbelly dace.
Tench.
Rosy Barb. Hailing from Afghanistan and Bangladesh, this little fish is tolerant of temperatures in …
Gold Barb. The gold bard, or Chinese barb, is an extremely popular cold-water fish. Any aquarium …
Two Spot Barb. This fish hails from Nepal, India, and Pakistan. The omnivorous two spot barb …
Bloodfin Tetra. Natives to Southern Brazil and Paraguay, both the standard bloodfin .
Coldwater fish in terms of the aquarium trade refers to any fish species that prefer cooler water temperatures. The optimal temperatures for these fish hover around the 68-degree mark, although each species’ temperature range may vary from the norm.
This document provides information on lobster culture and its management. It discusses the important lobster species for culture, their habitat and feeding habits. It describes the breeding technology, seed collection methods, and hatchery and nursery management practices. Grow-out can be done using land-based tanks or sea cages. Key water quality parameters and stocking densities are outlined. Finally, common diseases affecting farmed lobsters are identified along with control measures.
Fishes, amphibians, reptiles, and birds have paired pharyngeal ultimobranchial glands that secrete the hypocalcemic hormone calcitonin. The corpuscles of Stannius, unique glandular islets found only in the kidneys of bony fishes, secrete a peptide called hypocalcin.
Present status & future prospects in marine aquacultureKiritKene
This document provides an overview of the present status and future prospects of marine aquaculture in India. It discusses key topics like the major cultivable species, top aquaculture producer countries, present status of marine fisheries resources in India, financial facilities available, and future growth opportunities. The document contains tables and information on aspects like state-wise marine fish production, cultivable biological resources, site selection criteria, and the role of organizations like FAO in supporting the sector.
culture system - semi intensive, intensive, super intensice and cage.pptxHimanshuPatidar19
This document discusses different types of aquaculture systems including semi-intensive, intensive, and super intensive systems. It also discusses different cage culture systems used in aquaculture like fixed cages, floating cages, submersible cages, and submerged cages. Semi-intensive systems involve stocking fish at moderate densities and relying on natural foods supplemented with feed. Intensive systems rely on artificial feeds and management to maximize yields. Super intensive systems involve very high stocking densities and use of water treatment technologies like recirculating aquaculture systems.
This document provides an overview of reproductive biology in fishes. It discusses the different types of sexuality observed in fishes, including unisexuality, bisexuality, hermaphroditism, and parthenogenesis. It describes the reproductive cycles and hormones that regulate reproduction for both male and female fish. Key aspects covered include the gonads, sexual dimorphism, seasonal breeding patterns, and hormonal control of the reproductive system through the CNS-pituitary-gonad axis.
This document discusses estuaries and estuarine fisheries in India. It defines an estuary and notes that India has over 55 estuaries along its eastern and western coasts, totaling approximately 30,000 square kilometers. Several major river systems like the Ganges, Mahanadi, Godavari and Krishna form highly productive estuarine ecosystems. The document examines the fish production and ecology of estuaries like the Hooghly, Krishna, Godavari, Mahanadi, Chilka, Pulicat Lake, and Kerala backwaters. It provides details on fish catches, species diversity, and threats like overfishing in several of India's important estuarine systems.
The document discusses feed conversion ratio (FCR) and its calculation and application in aquaculture and livestock. FCR is calculated as feed given divided by animal weight gain, with no units. A lower FCR indicates higher weight gain from the feed. For dairy cows specifically, feed efficiency is calculated as energy-corrected milk divided by dry matter intake, which can be difficult to obtain on many dairy operations.
This document discusses the feeding habits and nutritional requirements of fish at different life stages. It begins by explaining that fish require energy, amino acids, fatty acids, vitamins, and minerals to sustain life and promote growth. It then discusses the feeding behaviors and nutritional needs of fish larvae, including their underdeveloped digestive systems and reliance on plankton and zooplankton. The document also categorizes different types of food sources for fish and classifies fish based on their dependence on food types and positions in the water column. Specific examples are provided of the feeding behaviors of fish larvae, juveniles, and adults.
Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) ...Sana_haroon
this is my presentation based on research paper title "Reproductive biology of the milk shark Rhizoprionodon acutus (Rüppell, 1837) from the Gulf of Suez, Red Sea, Egypt"
This was written by Amgad M. Shaaban et al., 2018
Which have Impact factor: 1.98
Le diaporama dédié à la culture du milkfish offrira une exploration approfondie des multiples facettes de cette pratique aquacole. En mettant en avant les conditions environnementales optimales, il abordera les techniques de reproduction, les régimes nutritionnels recommandés, ainsi que les défis et avantages inhérents à l'élevage du milkfish. Des visuels graphiques et des images saisissantes seront incorporés pour illustrer de manière vivante le cycle de vie du poisson et dépeindre les installations d'élevage modernes. En parallèle, des données économiques viendront étayer la présentation, mettant en relief l'impact financier de cette activité. L'aspect culturel du milkfish ne sera pas négligé, mettant en lumière son importance dans diverses régions et soulignant son rôle significatif tant sur le plan économique que social. En somme, ce diaporama vise à offrir une compréhension holistique de la culture du milkfish, alliant informations pratiques et perspectives culturelles.
This document summarizes a study on the reproductive biology of male pipefish (Trachyramphus bicoarctatus) in Lake Qarun, Egypt. The study found that the sex ratio was male to female of 1:1.37, significantly different than the expected 1:1 ratio. Males reached sexual maturity at a length of 7.9cm. Mature males and those brooding eggs were found from December to April. Male fecundity ranged from 42 to 111 eggs and was correlated to fish length. The reproductive period extended from December to April, peaking in February.
Yellowfin tuna are an important commercial fish found worldwide in tropical and subtropical oceans. They form schools and feed primarily on fish, crustaceans, and squids. According to this study, the major components of yellowfin tuna diet were teleost fish, crabs, squids, and shrimps. Overfishing is impacting some yellowfin tuna populations. The study of their feeding habits is important to understand ecosystem impacts and inform sustainable exploitation.
Food and Feeding habits of yellowfin tunaSalmashaik26
Yellowfin tuna are an important commercial fish found worldwide in tropical and subtropical oceans. They form schools and feed primarily on fish, crustaceans, and squids. According to this study, the major components of yellowfin tuna diet were teleost fish, crabs, squids, and shrimps. Overfishing is a concern, as the Eastern Pacific stock is overfished and some overfishing is occurring in the Indian Ocean. The study of their feeding habits is important to better understand their role in the ecosystem and to improve management strategies.
This document discusses culture techniques for yellowtail, including self-feeding patterns observed in a study. The study found that yellowtail exhibited two peaks in feeding activity per day, around dawn and dusk. Water temperature also influenced feeding behavior, with higher activity above 18 degrees Celsius. Environmental factors like light intensity and temperature affect yellowtail feeding rhythms and demands.
the presentation provides the details regarding the murrels or snakeheads which includes the basic taxonomy, some of the important species, distribution, special characters, its aquaculture potential, food and feeding habits, sexual dimorphism, parental care, age at maturity, the maturity stages, breeding season, courtship and mating, natural spawning, fecundity, induced spawning using ovaprim and HCG and LHRHa, and also the detailed facts regarding larval reariing.
This document provides information on two fish species: threadfin bream and pomfret. It discusses their taxonomic classification, identifying characteristics, distribution, breeding seasons, feeding habits, size at maturity, production trends, utilization, and exploitation. Threadfin bream belongs to the family Nemipteridae and six commercially important species are found in Indian waters. Pomfret belong to the family Stromatidae and include species like Pampus argentus and Pampus chinensis, which are an important part of local fisheries. Both species are harvested using various nets and trawlers.
This document provides information on the African catfish (Clarias gariepinus). It discusses the biology of C. gariepinus and the closely related species C. anguillaris. It also describes the natural breeding and artificial propagation of C. gariepinus, including hormone treatment of broodfish, incubation and hatching of eggs, nursing of fry, and feeding regimes for early fry and advanced fry in hatcheries. Semi-intensive polyculture of catfish and tilapia in earthen ponds is also summarized.
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2. INTRODUCTION
• Mugil cephalus is commonly called as flat head grey mullet.
• It is found in coastal tropical and subtropical waters worldwide.
• It shows catadromous migration.
SCIENTIFIC CLASSIFICATION:
Kingdom : Animalia
Phylum : Chordata
Class : Actinopterygii
Order : Mugiliformes
Family : Mugilidae
Genus : Mugil
Species : cephalus
3. DISTRIBUTION
• It is found in fresh ,brackish, marine habitats in depths ranging between 0-
120 metres and with temperatures between 8-24◦C.
• It is catadromous in nature migrating into marine waters for spawning.
• It is commonly called as flat head grey mullet,striped mullet, black mullet,
and sea mullet.
• The maximum length of M.cephalus is 120cm and with a maximum weight of
12kg.
• It is euryhaline species
4. DESCRIPTION
• It is characterised by the presence of 5 dorsal spines ,7-9 dorsal soft rays,3
anal spines and 8-9 anal soft rays.
• Body is slightly compressed and cylindrical in cross-selection
• Head is broad and flattened.
• It is characterized by the presence of well developed adipose eye lid.
• 1-6 rows of fine teeth are present
5.
6. INTRODUCTION
• Fishes of the family Mugilidae represents one of the major commercial resources of tropical
and warm temperate estuaries and their ecological function in food webs is of the greatest
importance.
• In the past, Mugilids were believed to be the most abundant species in almost all the
estuaries along the Indian coast and hence formed a very important species for the local
fishery.
• Unfortunately, after extensive land reclamation of lagoons and brackish water lakes together
with the constant pollution from agriculture and upstream industries and high fishing
pressure, the status of Mugilids is now fragile.
• Flathead grey mullet, M.cephalus is becoming endangered and rare .
• The mullets form one of the important fisheries of the estuaries and coastal waters of India
constitute less than 0.3% of the total marine landings.
7. OBJECTIVES
• Present aim of the study described their maturation; ova-diameter studies, gonado-somatic
index, spawning season and fecundity of M.cephalus were presented.
• Knowledge of spawning season and fishing location are instrumental in establishing time and
area closures to protect essential fish habitats along with modification of fishing gear to
enhance the survival of heavily exploited species .
• An increase in understanding the reproductive biology of mugilids is essential to determine
the parameters to be used in age-structured models of stock assessments.
8. MATERIALS AND METHODS
• This work was based on the examination of specimens collected from Krishna Estuarine
Region, East Coast of Andhra Pradesh.
• After measuring the total length and weight of each specimen, the belly was cut open to note
the sex, colour and general appearance of the gonads which were then weighed to the
nearest 0.1 g and preserved in 10 percent formalin.
• Observations on the maturation of gonads in adults, and the determination of the spawning
season has been carried out mainly on the basis of examination of the ovaries, since the
male gonad (testis) did not show identifiable changes during maturation.
.
9. • Ova diameters were taken on the ova collected from anterior, middle and posterior regions of
the left ovary.
• Ova were taken out on a micro slide and they were measured under the compound
microscope with the help of an ocular micrometer at a fixed magnification.
• At this magnification one micrometer division (md) in the ocular micrometer is equivalent to
0.02 mm.
• The ova diameter studies were carried out by measuring 70 ova from each ovary (stage III
and IV) in 50 individuals in the length range 14-30 cm Total length.
10. FECUNDITY
• Fecundity is defined as the number of ripening, ripe eggs found in the ovaries prior to
spawning.
• It is estimated to study the differences between stocks of fish.
• Fecundity can be used to identify a particular stock.
12. DEVELOPMENT OF OVA TO MATURITY
• The percentage frequency distribution of ova diameters in different stages of maturity are
estimated.
• In stage I the ova are smaller in size, irregular in shape and measure in size (diameter)
between 0.12 and 0.32 mm.
• In the ovaries in maturing stage, the ova range in size between 0.26 and 0.44 mm.
• In mature stage the size of ova varies between 0.44 and 0.62 mm.
• Few ripe ova present in the mature ovary range between 0.56 and 0.74 mm. in diameter.
• In the present study the frequency distribution of ova diameters in the mature ovary exhibit a
single group of ova that are released in a single spawning act.
• Mullets show a non-intermittent spawning, which is an indication of unimodal type of ova
diameter frequency distribution .
13. LENGTH AT FIRST MATURITY
• Estimation of minimum length of the fish at first maturity in a fish stock helps in the
determination of the spawning stock.
• Maturation of gonads starts before the spawning season and the ova become ripe.
• The size at which the fish becomes mature varies among different fish stocks.
• Length at first maturity in a species is determined on the basis of the minimum length at
which 50 per cent of individuals in stock become mature and spawn during the spawning
season.
• The present study on the minimum size at first spawning in the stocks of M. cephalus from
the Krishna estuarine region is based on 220 individuals collected from the fish landing
centre.
• Studies on the spawning season of M. cephalus show that the mature individuals migrate to
the off-shore areas for the purpose of spawning from late January to february.
14. • Females with maturing, mature and ripe ovaries were utilized in the study.
• In the samples collected, individuals measuring less than 13 cm were with immature
gonads, the smallest female with mature gonads was observed to belong to 13cm group.
• Females larger than 18cm are with mature gonads.
• 50 percent of the individuals in the 16cm length group are with mature gonads and hence
16cm length group was considered as the minimum size at maturity in this stock.
16. • The present study is based on gonad weights of fish collected from 132 female individuals in
the size range 13.4 to 30.5cm TL.
• The Gonado-Somatic index (GSI) values were considerably low (0.32 to 3.8) from February
to September, with the lowest value in the month of March.
• During this month the gonads are in spent condition as the fish are known to spawn from
January onwards.
• The development of gonads in the female fish commences from October and the Gonado-
Somatic index was ranged from 8.1 to 11.5 percent from October to January.
• The maximum value of Gonado-Somatic index was recorded in December.
• The Gonado-Somatic index from January onwards showed a decline indicating the beginning
of spawning
17.
18. SPAWNINg
• M.cephalus is known to mature in coastal waters and migrates into in the deeper oceanic
waters for the spawning.
• Hence in the present area of study only few specimens with ripe gonads were collected.
• Presence of a single group of ripe ova indicates that the ova develop synchronously in the
ovary and they spawn in a single spawning act.
19. SPAWNING SEASON
• In the present study spawning season of M. cephalus is determined based on indirect
evidence collected from the studies on the stages of maturation and Gonado-Somatic index
in the samples during different months.
• From late January, in the coastal waters, individuals with spent gonads started appearing in
catches.
• In the month of February number of individuals with spent gonads increased in number and
reached a peak.
• In March few individuals with spent gonads were noticed.
20. • The above data indicates that individuals of M. cephalus after becoming mature migrate to
the oceanic waters; spawn and the spent individuals migrate back into near coastal waters in
this region.
• From the above evidence on the stages of maturation of ovaries, and the Gonado-Somatic
Index it can be concluded that spawning takes place in this region during late January and
February.
• In South African waters M. cephalus was known to spawn two times in a year suggests that
M. cephalus may spawn more than once during a long spawning season
21. FECUNDITY
• In the present study fecundity in M. cephalus was estimated in adult females in length ranges
from 14.0 to 30.5cm TL whereas in weight ranged from 28 to 248g.
• Absolute fecundity in these specimens ranged from 0.4 to 5.2 million. In one specimen of
30cm TL weighing 248g absolute fecundity was estimated to be at 8.2 million.
• Earlier studies on fecundity of M. cephalus from India show that in Lake Pulicat the fecundity
ranged between 0.43 and 4.71 million in the specimens in the length range from 22 to 50cm
TL.
• A comparison of present data with the earlier studies on fecundity from Lake Pulicat show
that the stocks of mangrove swamp exhibit higher fecundity.
• Similar observations has been made out previously by several authors on the fecundity of
M. cephalus from India.
22. SEX-RATIO
• Knowledge of the sex-ratio in a fish population during different months or seasons is
essential to know their relative abundance in the spawning stocks.
• The adolescent and adult fish migrate in to offshore regions after the maturation of gonads
for spawning.
• After spawning they migrate back in to coastal waters and enter the water bodies near the
estuary.
• The migratory behaviour of the stocks accounts for the changes in the sex- ratio in the
samples.
• Earlier studies on sex- ratio of M. cephalus in the Lake Pulicat show that the sex ratio 1.56:
1 indicating the preponderance of males.
• Recently in Gulf of Mexico lagoon observed in the two species of Mugil, the sex-ratio
between males and females in 1: 1.1.
• The sex-ratio observed in the present study is 1.99: 1.
23. CONCLUSION
• Spawning season has observed from end of the January to February.
• Males outnumbered the females in the spawning stocks.
• In the present study area it is observed that M.cephalus is a non-intermmitent or single
spawner.
• Knowledge of the spawning season and reproductive biology helps in the effective
management of M.cephalus and useful for stock assesment studies.
24.
25. INTRODUCTION
• The Flathead grey mullet M.cephalus is a catadromous pelagic species found in various
habitats from shallow brackish and marine waters to lagoons, estuaries and rivers deltas.
• It tolerates salinity extremes as well as abrupt water quality changes.
• M.cephalus is common in the shallow waters of the eastern Mediterranean and Black sea .
• Like most Mugilids, this species reproduces at sea, after which fry undertake a trophic
migration shoreward to continue their development in food rich lagoons, estuaries, rivers
and even lakes .
26. OBJECTIVE
• The aim of the present work is to describe the reproductive physiology of M. cephalus in
Benghazi coast – eastern Libya.
• This study may prove useful to fishery management by providing information on seasonality
of spawning.
27. MATERIALS AND METHODS
• Monthly samples of M.cephalus were collected during the period from September 2014 to
August 2015 by trammel and gill nets from fishing landing site in Benghazi coast, eastern
Libya .
• A total 530 specimens of M.cephalus were sampled for studying the reproductive
physiology.
• The total length ranged from 19.5 to 47.4 cm, and total weight from 71.3 to 1231.8 gm.
• Fish was dissected to determine sex then the gonads were weighted to the nearest gm.,
state of maturity for each individual fish was determined into five stages: Immature, Mature,
Nearly Ripe, Spawning and Spent .
29. SEX-RATIO
• Sex ratio is more for females (fish = 56.2 %) than males (232 fish = 43.8 %) for the whole
population.
• Overall sex ratio was 1: 1.28 for males to females .
• The sex ratio was not constant throughout the different months; the numbers of females
exceed males in all months.
• The maximum percentage of females was recorded in December (59.0 %), January (60.0
%) and August (59.5 %).
30.
31. LENGTH AT FIRST SEXUAL MATURITY
• First maturation size for males is(L50 = 32.3 cm) .
• First maturation size was determined for females (L50 = 34.1 cm).
32. Gonado-Somatic Index (G. S. I.)
• M. Cephalus have a spawning season which extends from July to October.
• G. S. I for male was lower than that of female.
• In male, gradual increase was 4.67 % recorded in July reach 5.99 % in October.
• In females the average G. S. I. values were increased in July (7.57 %) to 8.93 % in October.
33. OOCYTE DIAMETERS
• The recorded average oocyte diameter of M. cephalus during the whole period of the
study was recorded.
• The minimum average oocyte diameter was recorded in April (188 µ ± 2.33) a sharp
increase in the average oocyte diameter was evident in July (489 µ ± 5.34), then
increased continued in the following months reaching the maximum values in August
(599 µ ± 11.04).
• The egg diameter in fish samples was very minute and difficult to measure in the period
from December till March.
34. FECUNDITY
• Ovaries of 225 M. cephalus were examined .
• Absolute fecundity ranged from 578981 to 3332599 for fish total length ranging from 19.5 to 47.4 cm
with overall average 1244657 ± 682896.3 whereas the average relative fecundity ranged from 29036 to
57352 / cm wit overall average 35375 ±10389.8.
35. • A total of 530 specimens of M. cephalus were sampled for studying the reproduction during
the period from September 2014 to August 2015 from fishing landing site in Benghazi coast,
eastern Libya.
• In the present work the overall sex ratio was 1: 1.28 for males and females of M. cephalus,
and these results are in agreement with those results of M. cephalus in Suez Canal, Egypt
(El-Mor, 1993).
• The sex ratio is not constant throughout the different months, particularly during the breeding
season of each species (Oren, 1975).
• Females are dominant sex in mullet populations (Peterson & Shehadeh, 1971).
• It is possible that the females are heavy and get caught in the gear in large numbers,
resulting in an unbalanced sex ratio (Broadhead, 1953).
36. • Generally, in the natural fish community males mature first before the females and are nearly
to participate in spawning activity (Mohammad, 1982).
• In the present work, the maturation size was determined for females L50 = 34.1 cm and for
males L50 = 32.3 cm.
• These values are more than that they have been recorded by (El-Mor, 1993) in Egyptian
Mediterranean Sea which L50 for males 30.1 cm and L50 for females 33.3 cm.
• These variations in the beginning of maturity sign may be depend on the water temperatures
or the different fishing methods in all different stations (Fimucane et al., 1978).
• In the present study, from the average gonado-somatic indices (G. S. I.) of males and
females M. cephalus have a definite breeding season, which extends from July to October.
• This is on agreement with the spawning season of M. cephalus in Egyptian Mediterranean
Sea (El-Mor, 1993).
37. • An increase in Oocyte diameters was evident in July (489 µ ± 5.34), and this increase
continued in the following months till October (599 µ ± 11.04), this is an agreement with the
spawning season of M. cephalus in the present study.
• The increase in egg diameters is mainly due to the deposition of large amounts of proteins
and lipids in the developing eggs.
• A part of these materials comes directly from ingested food but major proportion comes from
reserve of food deposits, during the active season in organs such as liver, muscles and fat
bodies (Larson, 1974).
• The number of eggs produced by females varies greatly according to species, size, age,
region, thus a considerable variability has been shown in different populations of mullets
(Oren, 1975).
38. CONCLUSION
• All individuals have definite breeding season which extends from July to October.
• An increase in Oocyte diameters was evident in July (489 µ ± 5.34), and this increase
continued in the following months till October (599 µ ± 11.04).
• The absolute fecundity ranged from 578981 to 3332599 for fish total length ranging from
19.5 to 47.4 cm, whereas relative fecundity ranged from 29036 to 57352 / cm.
• Females outnumbered the males in the spawning stock.
39. FINAL CONCLUSION
• Spawning season for M.cephalus in Krishna estuary is end of January to February and for
M.cephalus in Benzhagi coast is July to October.
• In Krishna waters males outnumbered females and in Benzhagi coast females outnumbered
males.
• In both the coasts there is a single spawning season.
• M.cephalus is a single spawner.
• Reproductive biology of M.cephalus is useful for stock assesment studies.
40. REFERENCES
• Rangaswamy CP.,1973 .Studies on the age and growth and food habits of the grey mullet
Mugil cephalus of the Lake Pulicat. J. Inland Fish. Soc. India.
• Das HR. 1977 The fecundity of the grey mullet, M. cephalus along Goa coast, Mahasagar.
10:79-82.
• Cardona L. 2001. Non-competitive coexistence between Mediterranean grey mullet
(Osteichthyes, Mugilidae): evidence from seasonal changes in food availability, niche
breadth and trophic overlap. J. Fish Biol. 59:729-744.
• Prasadam RD. 1970.Preliminary observations on the food and feeding habits of the grey
mullet Mugil macrolepis from Pulicat Lake, J. Zoo. Soc. India. 22:63-67.