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?
The document discusses India's fisheries management. It notes that India has vast inland and marine fisheries resources that provide food and employment. Management is undertaken by both central and state governments and includes regulations on gear, seasons and habitat protection. Five-Year Plans have aimed to increase production sustainably. Community-based and co-management initiatives also play a role in governance. Key challenges include sustainably utilizing resources and balancing conservation and livelihoods.
Introduction
Fish Health Management GOALS
Principles of fish health management
Factors affecting fish health
Common symptoms of diseases
General preventive measures
Proper Health Management through Manipulating the disease triangle
Conclusion
References
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.
Carps form the mainstay of aquaculture in India contributing over 85% of the total aquaculture production There are 61,259 species of vertebrates recognized world; over 30,700 are fish species of which 8,411 ore fresh water while 11,650 are marine. In India 2,163 spp. are fin fishes have been recorded from upland cold water (157; 7.26%) warm water of the plain (54; 20.99%), Brackish water (182; 8.41%) and marine environment (1,370; 63.43%). Some of these species are cultured at commercial level which covering a lot varieties of fin fishes The three Indian major carps, namely Catla (Catla catla), Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigal) contribute the bulk of production to the extent of 75 to85 percent of the total fresh water fish production, the three exotic carp such as Silver carp (Hypophthalmichthys molitrix) and Common carp (Cyprinus carpio ), Grass carp (Ctenopharyngodon idella )form the second important group to incorporate several other medium and minor carp and into the carp poly culture system several method were used because of their region specific consumer preference and higher market demand.
History
Carp culture in India was restricted only to a homestead backyard pond activity in west Bengal and Odisha until late 1950 s with seed from riverine sources as the only input resulting low level of production the technological breakthrough breeding of carp through hypophysation in 1957 freshwater aquaculture of the country the country till 1984 virtually laid the foundation of scientific carp farming in the country.
Important characteristics of Indian major carps:-
Indian major carp grow fast and can reproduce even in artificial ponds. They feed upon phytoplankton, zooplankton, decaying organic matter, aquatic plant etc. stomach is absent in the alimentary canal of the major carps. Three types of Indian major carps are cultured in
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.
Marine fisheries resources and marine species of India.pdf
ICAR-CMFRI Scientific and contributions in Marine Fisheries Resources management studies along the Indian coast, special focus on Fisheries resources and marine species identification
This document discusses hatchery management and natural fish propagation. It provides details on criteria for selecting fish species for culture, including that they must be able to withstand the local climate, grow quickly, reproduce successfully in captivity, accept artificial foods, be desirable to consumers, tolerate high densities, and resist disease. The document also describes the natural propagation process, including the development of sexual products like eggs and sperm, factors that determine propagation habits, and the fertilization process. Hatcheries aim to artificially propagate fish on a large scale to provide stock for aquaculture.
Fish nutrition and feed technology 4th sem (full sylabus)
This document discusses fish nutrition and feed technology. It covers fundamentals of fish nutrition including the importance of proper nutrition for fish farming. Fish require proteins, lipids, carbohydrates, vitamins and minerals for healthy growth. Energy is also essential and is derived from dietary nutrients. The document outlines various forms of energy partitioning in fish and methods of energy metabolism. It discusses laws of thermodynamics and units of energy measurement. Feed formulation involves balancing protein, energy and amino acid levels. The steps in feed formulation include initial protein and energy balancing, checking indispensable amino acid levels, and consideration of additives.
This document discusses the important physical, chemical, and biological properties for successful fish pond culture. It covers factors like temperature, depth, turbidity, light, dissolved oxygen, pH, carbon dioxide, hardness, alkalinity, ammonia, phosphorus, and dissolved solids. Maintaining optimal ranges for these various properties can ensure high fish productivity, prevent disease outbreaks, and support healthy aquatic ecosystems in the pond. The document emphasizes how closely managing water quality, food production, and fish health are interlinked for sustainable aquaculture.
Nutritional requirement of cultivable fin fish: larvae, juveniles and adults
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.
Cryopreservation of reproductive products of many aquatic species has been successfully achieved. ... Cryopreservation technology applied to the preservation of fish gametes in aquaculture plays an important role in seed production, genetic management of broodstock and conservation of aquatic resources
Poisonous glands are specialized glands found in some fish and amphibians that secrete a venomous or poisonous mucus. These glands occur in the skin of cartilaginous fish or are associated with spines and fins of bony fish. The glands use a holocrine secretion method to release their toxic venom, which functions as a protective device and kills bacteria on bottom-dwelling fish. Some poisonous fish include porcupinefish, boxfish, and goatfish, while venomous fish like stingrays, catfish, stonefish, and butterfly cod have venom glands associated with their spines that can inflict painful wounds.
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.
This document provides information on sea cucumbers (holothurians), including their biology, life cycle, reproduction, and aquaculture. It discusses that holothurians are economically important as food and that their skin and muscle layers are edible. It also describes their internal anatomy, feeding behavior, spawning season from March to April when eggs and sperm are released, and larval development. The document outlines aquaculture techniques for sea cucumbers such as pond culture and discusses broodstock maintenance and artificial breeding.
In aquatic animals such as fish respiration takes place through special respiratory organs called gills, however lung fish respiration takes place through lungs. Gills are present on both the sides of the head of fish. The gills are covered by gill covers also called operculum. When the fish open its mouth, water is drawn into the buccal cavity and passed through the gills. The gills contain special type of cells that absorb the oxygen present in water. The absorbed oxygen is then supplied to all the cells of body through blood. In the cells, oxygen is converted into carbon dioxide and returned back to gills through blood. Ultimately, the gills release the carbon dioxide in water passing through them.
Respiration in Fish
The gills of fish are very efficient; it is estimated gills can extract about 80% oxygen dissolved in water. In addition to the respiratory organs, the gills have an important role in maintaining the right balance of salts in the body.
Sargassum is a genus of brown macroalgae found in tropical and temperate oceans. It has a main axis with branched laterals bearing air bladders and receptacles with flask-shaped conceptacles containing sex organs. Reproduction is both vegetative through fragmentation and sexually through antheridia and oogonia forming in conceptacles. Porphyra is an edible red algae commonly known as nori. It has a thin blade-like thallus attached by a holdfast. Cells contain stellate chromatophores. Reproduction is sexual through carpogonia and spermatangia or asexually through neutral spores. Diatoms are a large group of algae with beautiful
Brown algae are characterized by cell walls containing cellulose and alginic acid. They reproduce sexually and asexually and have an alternation of generations life cycle. Brown algae are divided into three classes based on their life cycles: isogamous, heterogamous, and oogamous. Ectocarpus is a filamentous brown alga that is a model organism. Kelps are large brown algae with a diploid sporophyte generation and haploid gametophyte. Fucus is dioecious and releases gametes using tidal movements, with sperm chemotaxing towards eggs. Brown algae are used as sources of iodine, alginate, food, and
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.
Rotifers are microscopic aquatic animals of the phylum Rotifera. Rotifers can be found in many freshwater environments and in moist soil, where they inhabit the thin films of water that are formed around soil particles.
The mature ovum is covered by a plasma membrane that is surrounded by protective accessory egg membranes. These membranes include a primary membrane like the vitelline membrane in many animals, which adheres closely to the plasma membrane. Secondary membranes are produced by follicle cells surrounding the ovum, and tertiary membranes are secreted by the oviduct when the egg passes to the exterior. The various egg membranes provide protection and help prevent polyspermy in mammals.
Nematodes are commonly called roundworms. They have a cylindrical structure covered by a protective cuticle. They are bilaterally symmetrical and the sexes are usually separate. Nematodes parasitize domestic animals and can be found throughout the body. They vary greatly in size. The cuticle provides structure and protection while allowing flexibility. It also plays roles in osmoregulation and eliciting immune responses. Internal structures include the digestive tract, reproductive tract, and musculature that allows sinusoidal movement.
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.
A SEMINAR ON INDUCING AGENTS OF HYPOPHYSATIONKartik Mondal
The precise combination of environmental factors required for maturation, ovulation and spawning.
However, quite often, under farm conditions, the requisite environmental factors are either not available or do not persist for sufficient length of time for spontaneous maturation to occur.
The pioneering discovery of B.A. Houssay (1931) and Von Ihering (1935, 1937, Argentina) that fishes can be induced to spawn by injecting pituitary homogenates has somewhat mitigated the problem.
The principal advantage of this technique, referred to in aquaculture parlance as “Hypophysation.”
At what age does a fish attain a maturity
What is the perfect catchable or mark able size of the fish
It helps to calculate the life span and longevity of fish
It enables to estimate and compare growth rates of fish in different waters.
Good or bad growth can point out the suitability for rearing and stocking purposes
The timing of spawning migration of given species can be worked out .
The document discusses India's fisheries management. It notes that India has vast inland and marine fisheries resources that provide food and employment. Management is undertaken by both central and state governments and includes regulations on gear, seasons and habitat protection. Five-Year Plans have aimed to increase production sustainably. Community-based and co-management initiatives also play a role in governance. Key challenges include sustainably utilizing resources and balancing conservation and livelihoods.
Introduction
Fish Health Management GOALS
Principles of fish health management
Factors affecting fish health
Common symptoms of diseases
General preventive measures
Proper Health Management through Manipulating the disease triangle
Conclusion
References
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.
Carps form the mainstay of aquaculture in India contributing over 85% of the total aquaculture production There are 61,259 species of vertebrates recognized world; over 30,700 are fish species of which 8,411 ore fresh water while 11,650 are marine. In India 2,163 spp. are fin fishes have been recorded from upland cold water (157; 7.26%) warm water of the plain (54; 20.99%), Brackish water (182; 8.41%) and marine environment (1,370; 63.43%). Some of these species are cultured at commercial level which covering a lot varieties of fin fishes The three Indian major carps, namely Catla (Catla catla), Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigal) contribute the bulk of production to the extent of 75 to85 percent of the total fresh water fish production, the three exotic carp such as Silver carp (Hypophthalmichthys molitrix) and Common carp (Cyprinus carpio ), Grass carp (Ctenopharyngodon idella )form the second important group to incorporate several other medium and minor carp and into the carp poly culture system several method were used because of their region specific consumer preference and higher market demand.
History
Carp culture in India was restricted only to a homestead backyard pond activity in west Bengal and Odisha until late 1950 s with seed from riverine sources as the only input resulting low level of production the technological breakthrough breeding of carp through hypophysation in 1957 freshwater aquaculture of the country the country till 1984 virtually laid the foundation of scientific carp farming in the country.
Important characteristics of Indian major carps:-
Indian major carp grow fast and can reproduce even in artificial ponds. They feed upon phytoplankton, zooplankton, decaying organic matter, aquatic plant etc. stomach is absent in the alimentary canal of the major carps. Three types of Indian major carps are cultured in
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.
Marine fisheries resources and marine species of India.pdfB. BHASKAR
ICAR-CMFRI Scientific and contributions in Marine Fisheries Resources management studies along the Indian coast, special focus on Fisheries resources and marine species identification
This document discusses hatchery management and natural fish propagation. It provides details on criteria for selecting fish species for culture, including that they must be able to withstand the local climate, grow quickly, reproduce successfully in captivity, accept artificial foods, be desirable to consumers, tolerate high densities, and resist disease. The document also describes the natural propagation process, including the development of sexual products like eggs and sperm, factors that determine propagation habits, and the fertilization process. Hatcheries aim to artificially propagate fish on a large scale to provide stock for aquaculture.
This document discusses fish nutrition and feed technology. It covers fundamentals of fish nutrition including the importance of proper nutrition for fish farming. Fish require proteins, lipids, carbohydrates, vitamins and minerals for healthy growth. Energy is also essential and is derived from dietary nutrients. The document outlines various forms of energy partitioning in fish and methods of energy metabolism. It discusses laws of thermodynamics and units of energy measurement. Feed formulation involves balancing protein, energy and amino acid levels. The steps in feed formulation include initial protein and energy balancing, checking indispensable amino acid levels, and consideration of additives.
This document discusses the important physical, chemical, and biological properties for successful fish pond culture. It covers factors like temperature, depth, turbidity, light, dissolved oxygen, pH, carbon dioxide, hardness, alkalinity, ammonia, phosphorus, and dissolved solids. Maintaining optimal ranges for these various properties can ensure high fish productivity, prevent disease outbreaks, and support healthy aquatic ecosystems in the pond. The document emphasizes how closely managing water quality, food production, and fish health are interlinked for sustainable aquaculture.
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.
cryopreservation of fish gametes NBFGR gene bankAshish sahu
Cryopreservation of reproductive products of many aquatic species has been successfully achieved. ... Cryopreservation technology applied to the preservation of fish gametes in aquaculture plays an important role in seed production, genetic management of broodstock and conservation of aquatic resources
Poisonous glands are specialized glands found in some fish and amphibians that secrete a venomous or poisonous mucus. These glands occur in the skin of cartilaginous fish or are associated with spines and fins of bony fish. The glands use a holocrine secretion method to release their toxic venom, which functions as a protective device and kills bacteria on bottom-dwelling fish. Some poisonous fish include porcupinefish, boxfish, and goatfish, while venomous fish like stingrays, catfish, stonefish, and butterfly cod have venom glands associated with their spines that can inflict painful wounds.
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.
This document provides information on sea cucumbers (holothurians), including their biology, life cycle, reproduction, and aquaculture. It discusses that holothurians are economically important as food and that their skin and muscle layers are edible. It also describes their internal anatomy, feeding behavior, spawning season from March to April when eggs and sperm are released, and larval development. The document outlines aquaculture techniques for sea cucumbers such as pond culture and discusses broodstock maintenance and artificial breeding.
In aquatic animals such as fish respiration takes place through special respiratory organs called gills, however lung fish respiration takes place through lungs. Gills are present on both the sides of the head of fish. The gills are covered by gill covers also called operculum. When the fish open its mouth, water is drawn into the buccal cavity and passed through the gills. The gills contain special type of cells that absorb the oxygen present in water. The absorbed oxygen is then supplied to all the cells of body through blood. In the cells, oxygen is converted into carbon dioxide and returned back to gills through blood. Ultimately, the gills release the carbon dioxide in water passing through them.
Respiration in Fish
The gills of fish are very efficient; it is estimated gills can extract about 80% oxygen dissolved in water. In addition to the respiratory organs, the gills have an important role in maintaining the right balance of salts in the body.
Sargassum is a genus of brown macroalgae found in tropical and temperate oceans. It has a main axis with branched laterals bearing air bladders and receptacles with flask-shaped conceptacles containing sex organs. Reproduction is both vegetative through fragmentation and sexually through antheridia and oogonia forming in conceptacles. Porphyra is an edible red algae commonly known as nori. It has a thin blade-like thallus attached by a holdfast. Cells contain stellate chromatophores. Reproduction is sexual through carpogonia and spermatangia or asexually through neutral spores. Diatoms are a large group of algae with beautiful
Brown algae are characterized by cell walls containing cellulose and alginic acid. They reproduce sexually and asexually and have an alternation of generations life cycle. Brown algae are divided into three classes based on their life cycles: isogamous, heterogamous, and oogamous. Ectocarpus is a filamentous brown alga that is a model organism. Kelps are large brown algae with a diploid sporophyte generation and haploid gametophyte. Fucus is dioecious and releases gametes using tidal movements, with sperm chemotaxing towards eggs. Brown algae are used as sources of iodine, alginate, food, and
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.
Rotifers are microscopic aquatic animals of the phylum Rotifera. Rotifers can be found in many freshwater environments and in moist soil, where they inhabit the thin films of water that are formed around soil particles.
The mature ovum is covered by a plasma membrane that is surrounded by protective accessory egg membranes. These membranes include a primary membrane like the vitelline membrane in many animals, which adheres closely to the plasma membrane. Secondary membranes are produced by follicle cells surrounding the ovum, and tertiary membranes are secreted by the oviduct when the egg passes to the exterior. The various egg membranes provide protection and help prevent polyspermy in mammals.
Nematodes are commonly called roundworms. They have a cylindrical structure covered by a protective cuticle. They are bilaterally symmetrical and the sexes are usually separate. Nematodes parasitize domestic animals and can be found throughout the body. They vary greatly in size. The cuticle provides structure and protection while allowing flexibility. It also plays roles in osmoregulation and eliciting immune responses. Internal structures include the digestive tract, reproductive tract, and musculature that allows sinusoidal movement.
This document provides information on the presentation "Cestodes" including:
- Cestodes, also known as tapeworms, are flat, ribbon-shaped endoparasites that live in the digestive tracts of vertebrates. They have an indirect life cycle requiring an intermediate host.
- The document covers the morphology, classification, life cycles, and pathogenic effects of important tapeworm species like Diphyllobothrium latum and Ligula intestinalis.
- Tapeworm infections can cause inflammation, tissue damage and pathology in the intestines and other organs of fish hosts. This can lead to problems like reduced growth, organ damage, and sometimes mortality.
Cestodes, or tapeworms, are flat segmented parasitic worms that infect the intestines of humans and other animals. They are generally long and segmented, with a head or scolex region containing suckers or grooves for attachment. The body is made up of repeating segments called proglottids that contain reproductive organs. There are two main orders of tapeworms that infect humans - pseudophyllideans and cyclophyllideans. Diphyllobothrium latum, the fish tapeworm, has a complex life cycle involving freshwater fish and copepods as intermediate hosts before infecting the human intestine as an adult worm.
Zebra Fish- Genome, Morphology,Embryonic Development, A model organism Subhradeep sarkar
The zebrafish is a popular model organism used in scientific research due to its many advantages. It has a fully sequenced genome that is similar to humans and contains around 22,000 genes. The zebrafish develops rapidly, with major organ systems evident within days of fertilization. This, along with external fertilization and transparent embryos, makes early development easy to observe. The zebrafish genome also contains regions that are syntenic with human chromosomes, making it useful for studying human health and disease.
Bases of classification_nasif_sadat.pptxNasifSadat
Cleavage is a series of mitotic cell divisions that transforms the zygote into a multicellular structure. In protostomes, the blastopore develops into the mouth, while in deuterostomes it develops into the anus. Other key differences are that deuterostomes have a more complex body plan, mono-ciliated cells, fewer phyla, and the mesoderm forms from the archenteron.
Bases of classification_nasif_sadat.pptxNasifSadat
Cleavage is a series of mitotic cell divisions that transforms the zygote into a multicellular structure. In protostomes, the blastopore develops into the mouth, while in deuterostomes it develops into the anus. Other key differences are that deuterostomes have a more complex body plan, mono-ciliated cells, fewer phyla, and the mesoderm forms from the archenteron.
The document summarizes the larval stages of various animal phyla. It describes different free-swimming and crawling larval forms such as planula, cydippid muller larva, actinula, parenchymula, amphiblastula, miracidium, cercaria, oncomiracidium, trochophore, nectochaete, cyphonautes, nauplius, zoea, megalopa, phyllosoma, metanauplius, mysis, pluteus, bipinnaria, brachiolaria, ophiopluteus, and tornaria. These larval stages are characteristic of phyla such as Por
Algae: general characters and classificationBIYYANI SUMAN
Algae are a diverse group of photosynthetic organisms that are distinguished by their lack of tissues, their predominantly aquatic habitat, and unicellular or multicellular thalli not differentiated into roots, stems, and leaves. They range in size from microscopic to large seaweeds and reproduce both sexually through gametes and asexually through cell division or fragmentation. Major divisions of algae are classified based on pigments, food storage, flagella structure, cell and thallus structure, and life cycles.
Algae are defined as small autotrophic organisms that do not show differentiation of cells or tissues. Their reproductive organs are unicellular and all cells are fertile if multicellular. They range in size from microscopic to single-celled to large seaweeds. Algae are eukaryotic photoautotrophs that primarily inhabit aquatic habitats. They contain chloroplasts and carry out photosynthesis using pigments like chlorophyll.
biology description about phylum chordata.pptxSewunaMethhara
The document discusses characteristics of the phylum Chordata. It notes that chordates possess four defining features: a notochord, dorsal hollow nerve cord, pharyngeal slits, and muscular tail. It then describes classes within Chordata including Chondrichthyes (cartilaginous fishes like sharks) and Osteichthyes (bony fishes). Key features of Chondrichthyes are that they have a heterocercal tail fin, placoid scales, and some are ovoviviparous. Osteichthyes are distinguished by having bones, a swim bladder, and mostly oviparous reproduction.
Scales are a type of integumentary structure found in fish that provide both external protection and flexibility. There are four main types of scales - cosmoid, ganoid, placoid, and leptoid scales. Leptoid scales are further divided into cycloid and ctenoid scales. Cosmoid scales are very rare today and resemble fused placoid scales. Placoid scales are found on sharks and rays and resemble teeth. Ganoid scales have a bony base layer and are rhomboid in shape. Cycloid scales have a smooth outer edge while ctenoid scales have teeth along the outer edge.
Similar to Eggs and larvae identification biology in fin fish (20)
Marine fisheries regulation act (mfra), and its amendments of gujrat and dama...Ashish sahu
Marine Fisheries Regulation Act
An Act to provide for the regulation of fishing by fishing vessels in the sea along the coast line of the State. (1) This Act may be called the Kerala Marine Fishing Regulation Act, 1980. (2) It extends to the whole of the State of Kerala.
Ocean acidification is the ongoing decrease in the pH value of the Earth's oceans, caused by the uptake of carbon dioxide (CO 2) from the atmosphere. ... When carbon dioxide dissolves into seawater, it forms carbonic acid (H2CO3). Ocean acidification impacts many species, especially organisms like oysters and corals.
Ocean acidification reduces the amount of carbonate, a key building block in seawater. This makes it more difficult for marine organisms, such as coral and some plankton, to form their shells and skeletons, and existing shells may begin to dissolve. ... The impacts of ocean acidification are not uniform across all species.
Mangroves and their importance with Threats iucn pptAshish sahu
A mangrove is a shrub or tree that grows in coastal saline or brackish water. ... Mangroves are salt-tolerant trees, also called halophytes, and are adapted to live in harsh coastal conditions. They contain a complex salt filtration system and a complex root system to cope with saltwater immersion and wave action.
Mangroves are defined as assemblages of salt tolerant trees and shrubs that grow in the intertidal regions of the tropical and subtropical coastlines. They grow luxuriantly in the places where freshwater mixes with seawater and where sediment is composed of accumulated deposits of mud.
Fisheries crime and their sollution pptAshish sahu
What is fisheries crime?: Fisheries crime is an ill-defined legal concept referring to a range of illegal activities in the fisheries sector. These activities – frequently transnational and organized in nature – include illegal fishing, document fraud, drug trafficking, and money laundering.
Illegal fishing is a key driver of global overfishing, it threatens marine ecosystems, puts food security and regional stability at risk, and is linked to major human rights violations and even organized crime.
Iconic species are socially, culturally and economically important, and the community expects them to be effectively managed and protected.
What is a flagship species? A flagship species is a species selected to act as an ambassador, icon or symbol for a defined habitat, issue, campaign or environmental cause. ... Flagship species are usually relatively large, and considered to be 'charismatic' in western cultures.
Collection device of fish eggs and larvae pdfAshish sahu
First, an incision is made in her abdomen and then a small tube is inserted. The farmer then puts his mouth on the tube and sucks out a sWhen the internal ovaries or egg masses of fish and certain marine animals are ripe for spawning they are called roe.mall quantity of eggs for examination. If they're the right color and consistency, he'll kill the animal and harvest the caviar.When the internal ovaries or egg masses of fish and certain marine animals are ripe for spawning they are called roe. I think the best way is to use a toothpick and place them on something flat like a small chunk of marble or any flat ornament. Then place in a submerged container. Don't let the eggs hit open air. Well, the eggs in my breeding tank hatched, but overnight the fry either escaped or died
Mollusca of India and need for conservationAshish sahu
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda. The members are known as molluscs or mollusks. Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species
my common fisheries related post for jrf matsya jagat by Ashish sahuAshish sahu
The document appears to be a log of communications from "Matsya jagat/Ashish sahu" on January 16, 2021. It contains over 110 entries of text from "Ashish sahu" on that date, suggesting it records an extensive conversation or set of notes. However, the document provides no other context around the topic being discussed or purpose of the log.
Goodbye, Gillnets Belize bans deadly fishing gear, protecting countless marine animals Magazine Opting Out Amazon packages are awash in plastic, and shoppers want alternatives Q&A with Sam Waterston On cod, climate change, and his ... Ocean Council Susan Rockefeller, Founder Kelly Hallman, Vice Chair Dede McMahon, Vice Chair Anonymous Samantha Bass Violaine and John Bernbach Rick Burnes Vin Cipol
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Acharya Narendra Deva University of Agriculture and Technology is a university located in Kumarganj, Faizabad, Uttar Pradesh, India, established in 1975. It is named after the politician and educator Narendra Deva, who served as vice chancellor of the University of Lucknow and Banaras Hindu University. It also has constituent colleges in Ambedkar Nagar district and Azamgarh district, as well as a planned college in Gonda district.
Acharya Narendra Deva University of Agriculture and TechnologyAshish sahu
Acharya Narendra Deva University of Agriculture and Technology
Acharya Narendra Deva University of Agriculture and Technology is a university located in Kumarganj, Faizabad, Uttar Pradesh, India, established in 1975. It is named after the politician and educator Narendra Deva, who served as vice chancellor of the University of Lucknow and Banaras Hindu University. It also has constituent colleges in Ambedkar Nagar district and Azamgarh district, as well as a planned college in Gonda district.
These zones, called Exclusive Economic Zones (EEZs), extend 200 nautical miles from a country's coastline. Within the EEZ, the coastal country sets and enforces rules on ocean activities like fishing, drilling, and mining without international consultation. Oceana works to protect marine ecosystems and species through policy advocacy and legal victories aimed at banning shark finning and overfishing. The organization also campaigns against habitat destruction and supports ecosystem-based fisheries management.
Impact of climate change in atmosphere of oceanAshish sahu
How does climate change effect the ocean?
5 ways that climate change affects the ocean
Higher temperatures are bad for fish — and for us.
Polar ice is melting.
Rising sea levels represent a slow, seemingly unstoppable threat.
Warming oceans alter currents.
Climate change is affecting the chemistry of seawater.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive function. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
Three main methods for pond management are adding aeration, water treatments like beneficial bacteria, and weed and algae controls. The single best water management strategy you can implement is adding pond aeration.
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Is Email Marketing Really Effective In 2024?Rakesh Jalan
Slide 1
Is Email Marketing Really Effective in 2024?
Yes, Email Marketing is still a great method for direct marketing.
Slide 2
In this article we will cover:
- What is Email Marketing?
- Pros and cons of Email Marketing.
- Tools available for Email Marketing.
- Ways to make Email Marketing effective.
Slide 3
What Is Email Marketing?
Using email to contact customers is called Email Marketing. It's a quiet and effective communication method. Mastering it can significantly boost business. In digital marketing, two long-term assets are your website and your email list. Social media apps may change, but your website and email list remain constant.
Slide 4
Types of Email Marketing:
1. Welcome Emails
2. Information Emails
3. Transactional Emails
4. Newsletter Emails
5. Lead Nurturing Emails
6. Sponsorship Emails
7. Sales Letter Emails
8. Re-Engagement Emails
9. Brand Story Emails
10. Review Request Emails
Slide 5
Advantages Of Email Marketing
1. Cost-Effective: Cheaper than other methods.
2. Easy: Simple to learn and use.
3. Targeted Audience: Reach your exact audience.
4. Detailed Messages: Convey clear, detailed messages.
5. Non-Disturbing: Less intrusive than social media.
6. Non-Irritating: Customers are less likely to get annoyed.
7. Long Format: Use detailed text, photos, and videos.
8. Easy to Unsubscribe: Customers can easily opt out.
9. Easy Tracking: Track delivery, open rates, and clicks.
10. Professional: Seen as more professional; customers read carefully.
Slide 6
Disadvantages Of Email Marketing:
1. Irrelevant Emails: Costs can rise with irrelevant emails.
2. Poor Content: Boring emails can lead to disengagement.
3. Easy Unsubscribe: Customers can easily leave your list.
Slide 7
Email Marketing Tools
Choosing a good tool involves considering:
1. Deliverability: Email delivery rate.
2. Inbox Placement: Reaching inbox, not spam or promotions.
3. Ease of Use: Simplicity of use.
4. Cost: Affordability.
5. List Maintenance: Keeping the list clean.
6. Features: Regular features like Broadcast and Sequence.
7. Automation: Better with automation.
Slide 8
Top 5 Email Marketing Tools:
1. ConvertKit
2. Get Response
3. Mailchimp
4. Active Campaign
5. Aweber
Slide 9
Email Marketing Strategy
To get good results, consider:
1. Build your own list.
2. Never buy leads.
3. Respect your customers.
4. Always provide value.
5. Don’t email just to sell.
6. Write heartfelt emails.
7. Stick to a schedule.
8. Use photos and videos.
9. Segment your list.
10. Personalize emails.
11. Ensure mobile-friendliness.
12. Optimize timing.
13. Keep designs clean.
14. Remove cold leads.
Slide 10
Uses of Email Marketing:
1. Affiliate Marketing
2. Blogging
3. Customer Relationship Management (CRM)
4. Newsletter Circulation
5. Transaction Notifications
6. Information Dissemination
7. Gathering Feedback
8. Selling Courses
9. Selling Products/Services
Read Full Article:
https://digitalsamaaj.com/is-email-marketing-effective-in-2024/
Credit limit improvement system in odoo 17Celine George
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Beyond the Advance Presentation for By the Book 9John Rodzvilla
In June 2020, L.L. McKinney, a Black author of young adult novels, began the #publishingpaidme hashtag to create a discussion on how the publishing industry treats Black authors: “what they’re paid. What the marketing is. How the books are treated. How one Black book not reaching its parameters casts a shadow on all Black books and all Black authors, and that’s not the same for our white counterparts.” (Grady 2020) McKinney’s call resulted in an online discussion across 65,000 tweets between authors of all races and the creation of a Google spreadsheet that collected information on over 2,000 titles.
While the conversation was originally meant to discuss the ethical value of book publishing, it became an economic assessment by authors of how publishers treated authors of color and women authors without a full analysis of the data collected. This paper would present the data collected from relevant tweets and the Google database to show not only the range of advances among participating authors split out by their race, gender, sexual orientation and the genre of their work, but also the publishers’ treatment of their titles in terms of deal announcements and pre-pub attention in industry publications. The paper is based on a multi-year project of cleaning and evaluating the collected data to assess what it reveals about the habits and strategies of American publishers in acquiring and promoting titles from a diverse group of authors across the literary, non-fiction, children’s, mystery, romance, and SFF genres.
How to Configure Time Off Types in Odoo 17Celine George
Now we can take look into how to configure time off types in odoo 17 through this slide. Time-off types are used to grant or request different types of leave. Only then the authorities will have a clear view or a clear understanding of what kind of leave the employee is taking.
How to Show Sample Data in Tree and Kanban View in Odoo 17Celine George
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(T.L.E.) Agriculture: Essentials of GardeningMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏.𝟎)-𝐅𝐢𝐧𝐚𝐥𝐬
Lesson Outcome:
-Students will understand the basics of gardening, including the importance of soil, water, and sunlight for plant growth. They will learn to identify and use essential gardening tools, plant seeds, and seedlings properly, and manage common garden pests using eco-friendly methods.
Front Desk Management in the Odoo 17 ERPCeline George
Front desk officers are responsible for taking care of guests and customers. Their work mainly involves interacting with customers and business partners, either in person or through phone calls.
Beginner's Guide to Bypassing Falco Container Runtime Security in Kubernetes ...anjaliinfosec
This presentation, crafted for the Kubernetes Village at BSides Bangalore 2024, delves into the essentials of bypassing Falco, a leading container runtime security solution in Kubernetes. Tailored for beginners, it covers fundamental concepts, practical techniques, and real-world examples to help you understand and navigate Falco's security mechanisms effectively. Ideal for developers, security professionals, and tech enthusiasts eager to enhance their expertise in Kubernetes security and container runtime defenses.
Beginner's Guide to Bypassing Falco Container Runtime Security in Kubernetes ...
Eggs and larvae identification biology in fin fish
1. CHARACTERS USED IN THE IDENTIFICATION
OF FISH EGGS AND LARVAE
Ashish sahu
2. IDENTIFICATION OF FISH EGGS
The important characters generally used in identifying
fish eggs are:
1).Shape of the egg 2).Size (diameter)
3).Nature of egg membrane-
smooth, sculptured etc.
4).Extent of perivitelline space
5).Presence or absence of oil
globules
6).Size of oil globules
7).Homogenous or segmented
yolk
8).Embryonic characters
4. In the later stage of development of the embryo the
following characters are used.
1) Presence or absence of pigmentation on yolk sac or
oil globule.
2) Pigmentation pattern on the embryo.
3) Degree of pigmentation of the eyes.
5. 1) Shape of the egg:
Spherical-Most fish eggs are spherical in shape.
Mugil cephalus –striped mullet
Oval or Pear shaped- Stolephorus (anchovies),
Gobies, Blennies, some pomacentrids.
Eggs laid in masses or nests are usually not round
because they are deformed by adjacent eggs.
Non spherical eggs are more common in demersal eggs
than in pelagic eggs. Demersal eggs- Clupea harengus,
Capelin
6. 2).Size
Most fish eggs are about 1 mm in diameter, with the
size range of about 0.5 mm to about 8 mm.
Range of diameter of egg Some examples
0.5-1.0mm Caranx spp.
Cynoglossus, Kowala,
Anodontostoma, Mackerel
1.0-1.5mm Saurida spp.
S.longiceps, S.fimbriata, Coilia
1.5-2mm Chirocentrus
Fistularia
Above 2mm Eel, Trichiurus
7. Pelagic eggs are generally smaller (0.5 mm to 5.5 mm)
than demersal eggs (up to 8 mm), and since pelagic eggs
are rare in freshwater fishes, eggs of marine fishes are
smaller than those of freshwater fishes.
Mouth-brooding marine catfishes (ariids) have the largest
eggs of any teleost- 14 to 26mm.
8. 3).Chorion texture
The chorion of most fish eggs is smooth.
The eggs of some species are ornamented with
filaments that are characteristic of particular
species.( Atheriniforms, which includes the
halfbeaks(hemiramphidae) and flying fishes
(exocoetidae), have filaments on their eggs)
Other fishes have sculpturing of their egg chorions.
Similar hexagonal sculpturing seems to have developed
independently in several groups the right-eyed
flounders, the rattails, pearlsides, and the lizardfishes
(synodontidae)..
9. 4). Perivitelline Space.
Immediately following spawning during a process called water
hardening, a space (perivitelline space) develops between the
inner edge of the chorion and the membrane around the
cytoplasm of the egg itself.
The relative width of the perivitelline space changes little
during the rest of embryonic development. In most species it is
fairly narrow < 0.1 mm), But quite wide in (e.g., in flathead sole
[Hippoglossoides elassodon], Sardinella spp.
Filaments are more common in demersal eggs
than in pelagic eggs
Chorion of pelagic eggs is thinner than that of
demersal eggs
10. 5). Oil globules (size and number)
• Oil globules are characteristic features of most pelagic
fish eggs.
• Their absence is an important character in certain groups
(e.g., most right-eyed flounders [pleuronectids]),
Sardinella sirm, Chanos chanos, Opisthopterus tardoore,
Muraenid eels.
• Most eggs possess one oil globule of a specific
size(Trichiurus-0.65mm), but some eggs have more than
100 oil globules of irregular size(Setipina, kowala,
Anodontostoma spp. )
• The placement of oil globules within the egg relative to
the developing embryo varies, and in some fishes may
change during development
11. 6). Yolk characters
The yolk of most fish eggs is homogeneous .
But it is segmented in some, notably in lower teleosts such as
herring-like fishes (clupeiforms), eels (anguilliforms), and
salmon and their relatives (salmoniforms), and in some higher
teleosts such as jack mackerel (Trachurus symmetricus).
The color of the oil globules themselves, as well as any
pigmentation on them, is also an important character –
Pigment on oil globule seen in Caranx spp. and Trichiurus
Oil globule in yolk at anterior part- Caranx spp. and Mullidae
family.
The yolk of most pelagic eggs is transparent, but in many
demersal eggs it is opaque and colored.
12. 7).Embryo Characters.
As the embryo develops, it acquires characters that help
identify the egg. Pigment often forms and is seen in
characteristic patterns on the embryo, the yolk sac, and oil
globules.
Myomeres form and reach nearly the number of vertebrae
found in the adults during embryonic development.
The basic body shape of the larva can be seen in later
embryos: whether it will be elongated or deep-bodied,
and the relative length of the gut.
Some species develop rays in some fins, and some of
these can be elongated, pigmented, and ornate.
The state of development at hatching is another character
that varies among species.
In general, larvae from demersal eggs are further along in
development than those from pelagic eggs.
13. A. striped mullet (Mugil cephalus):
small egg, no oil globules, sculptured
chorion, well-developed embryo.
B. Pacific saury (Cololabis saira):
ovoid egg; chorion with filaments;
well-developed, heavily pigmented
embryo.
C. boxfishes (Ostraciidae): slightly
ovoid egg, heavily sculptured
chorion.
D. Pacific sardine (Sardinops sagax):
wide perivitelline space, embryo
coils more than one revolution.
E. Pacific viperfish (Chauliodus
macouni): large egg, wide
perivitelline space
F. Pacific hake (Merluccius productus): oil globule, pigment bands on embryo, eye of embryo
well developed. G. Pacific spiny lump sucker (Eumicrotremus orbis): embryo well developed
before hatching. H. king-of-the-salmon (Trachipterus altivelus): large egg, ornamented
elongate dorsal fin rays of embryo develop in egg. I. black-belly dragonfish (Stomias
atriventer): small egg, double egg membrane, wide perivitelline space.
14. IDENTIFICATION OF FISH LARVAE
• M11.11.Morphology 2.Pigments
3.Meristic Characters
8.Specialized Larval Characters
Myomeres Fin Rays
Head
spines
6.Gass bladder
4.Gut
5.Eyes
7.Shape and Size of the body
16. 1.Morphology
Larval shape can vary from stout and robust to quite
slender and elongated
The ratio of body depth at the pectoral fin to standard
length is usually sufficient to characterize the overall body
shape.
The head and eye size and shape may also be important.
The length of the gut, measured as the ratio of the pre anal
length to standard length is quite useful.
As larval shape characters vary with development, so the
size and stage of development should be noted when
comparing the shape of an unknown larva to illustrations
and descriptions of known specimens.
18. 2.Pigments
• Pigmentation available as taxonomic characters on
larvae is limited to melanophores, since other pigment
cells (e.g., xanthophores) do not retain their color in
currently used fixatives and preservatives.
• In some cases, pigmentation consists of a group of
melanophores in a specific area. In others, the
pigmentation consists of an individual melanophore.
• Preflexion larvae are less pigmented than later larvae.
• In most fishes, between the preflexion and
transformation stages, there is a definite larval pigment
pattern, which is relatively stable and unique to species
in many cases.
19. 1. Heavily pigmented
Holocentridae, Belonidae, Balistidae,
Coryphaenidae, Pegasidae, Istiophoridae and
Cephalacanthidae
2.Only some parts of the body are pigmented -
Exocoetidae, Atherinidae, Theraponidae, mullidae,
Stromateidae, Lobotidae and Platycephalidae
3.Few pigments - prolarvae of Engraulidae,
Apogonidae, Serranidae, Leiognathidae,
Scomberomoridae, Thunnidae, Pleuronectidae and
Cynoglossidae
20. 3.Meristic Characters
Myomeres:
• Myomeres are the first meristic character to stabilize,
and the number usually reflects the number of adult
vertebrae.
• The number of vertebrae varies from, 20 ocean
sunfishes to 200 (e.g., most eels and relative
[elopiformes]).
• Use of polarized light often facilitates counting
myomeres.
• Myosepta are frequently more clear than the
myomeres, and if they are counted, two should be
added to the count to account for the myomeres
anterior and posterior to the first and last myosepta.
22. • Prolarvae of Balistidae, Aluteridae,
Monacanthidae and Tetradontidae - 24
myomeres
• Mugilidae, Sphyraenidae, Carangidae- 23 to 24
myomeres
• Clupeidae,Engraulidae,Thunnidae,Belonidae-
35 to 40 myomeres
• Dussumeiridae, Bermacerotidae->50 nos
• Muraenoid leptocephalus -120 to 140 nos
23. Fin Rays:
The developing median fins contain several bits of
taxonomic information.
The principal caudal fin count is often an ordinal character
and since it generally reaches its adult state shortly after
flexion, it is very useful and relatively easy to determine in
larvae.
The number, position, and order of development of the
dorsal and anal fins, and their composition in terms of
spines and soft-rays, are important characters.
The length and number of rays of the pectoral fin are useful
characters. The number of pectoral rays may vary within
species and among species in a genus.
The pelvic fin position and formula is generally stable at a
high level of classification (order)
24. Head spines:
Some fishes have head and operculum spines which
are important as armour against predators.
Spination is useful diagnostically for most marine fishes
that have pelagic larvae.
Spines are present in the pre-larvae of all perciformes.
Spines are important diagnostically for Lobotidae (head
spines) and cobitidae (spines below the eye)
Larval head spines are prevalent in sculpins and
scorpion fishes (scorpaenids) and occur in some
members of groups such as squirrelfishes and their
relatives (beryciforms), perch-like fishes, and flatfishes
(pleuronectiforms).
25. 4.Gut
• All fish have a rudimentary straight gut (alimentary
canal) as pre-larvae
• The gut folds or coils as the digestive tract develops
and as the diet changes, with the timing and shape
differing between species
• The anus tends to move closer to the head as a fish
develops
Vent is generally situated behind the midpoint of the body - Prolarvae of
Clupeidae, Dussumieriidae, Engraulidae and Synodontidae.
Vent is far forward - Prolarvae of Brogmacerotidae, Atherinidae,
Trypauchenidae and Blenniidae
26. 5.Eyes
Most fish larvae have round eyes except in
Clupeoid larvae which have oval eyes.
Most early pre-larvae - no pigment in their
eyes ( pigment appears after one day)
Belonidae and Adrianichthyidae - eyes are
already developed and densely pigmented
during hatching .
27. 6.Gass bladder
By the Pre-larval stage- most species develop a
visible gas bladder- shape, size and position.
The larvae of Clupeiformes and Gobiidae -visible
swim bladders .
Juvenile or adult - gas bladder is usually not
visible.
Larvae of Ambassis spp. are transparent as adult,
but once fixed in formaldehyde their internal
features are not visible.
28. 7.Shape and Size of the body
Prolarva of Leiognathus - 1.2 to 1.4 mm
• Engraulis - 2.2 to 3.0 mm
• Epinephelus spp. - 1.4 to 1.6 mm
• Sillago spp. - 1.6 to 2.0 mm
• Pleuronichthys -3.6 to 3.7mm
Elongate- Clupeidae, Belonidae, Hemirhamphidae, Syngnathidae,
Synodontidae, and Blenniidae
Slender - Sillaginidae, Sphyraenidae, Bregmacerotidae, Cepolidae, Gobiidae-
Elongate ribbon like- Muraenidae and Ophichthyidae
Short fusiform body-Mugilidae, Pomadasyidae, Thunnidae, Scombridae,
Scomberomoridae, Stromateidae, Scorpaenidae
Globular- Ostraciontidae and Tetraodontidae
Deeply compressed body- Flatfishes
29. 8..Specialized Larval Characters
Specialized characters of larvae are those that
are overgrown or otherwise lost by the end of
the juvenile stage.
Such as elongated fin rays, trailing gut,
serrated fi spines, stalked eyes….
30. 8.Higher-Level Characters
As larvae of more and more fishes started to be recognized, it
became apparent that closely related species looked more
similar to each other than to more distantly related species.
For example, tarpons (elopiforms), bonefishes (albuliforms),
and eels all have a leptocephalus (leaf-like) larval morphology.
The larvae are shaped like willow leaves, they are laterally
flattened and taper anteriorly and posteriorly. They are lightly
pigmented and possess large, sometimes fang-like teeth.
Among the orders with leptocephali, the tarpons and
bonefishes have forked tails, whereas the eels have pointed
tails.
31. REFERENCE
• Miller, B.S. and Kendall, A.W., 2009. Early life history
of marine fishes (Vol. 36, No. 4). Berkeley: University
of California Press.
• Termvidchakorn, A. and Hortle, K.G., 2013. A guide to
larvae and juveniles of some common fish species
from the Mekong River Basin. Mekong River
Commission.
• James, P.S.B.R., 1989. Proceedings of the summer
institute in recent advances on the study of marine
fish eggs and larvae.