Reproduction is a fundamental biological process which enables continuation of species. In fisheries biology, reproduction assumes greater significance to understand sexual dimorphism, process of maturation, size or age of maturity, breeding season, spawning area, sexual segregation, migration, fecundity, embryonic and larval development and recruitment. Most of the management strategies in capture fisheries are based on reference points that are the manifestations of reproductive biology. In aquaculture, knowledge of reproductive biology of a fish is essential for hatchery production of fish feeds. , Nazmul Haque Syekat

1. Course Title : Fish Hatchery Operation and Management
Course Code : FIMS 3209, Year 3 Term 2
An Assignment On : “Breeding Biology & Parameters of Finfish and
Shellfish”
Submitted to Submitted by
Dr. Shyamal Kumar Paul
Assistant Professor ,
Department of Fisheries & Marine
Science , Noakhali Science & Technology
University
Nazmul Haque Syekat
Roll: ASH1802050M
Department of Fisheries & Marine
Science , Noakhali Science &
Technology University
Date of Submission : 12th April 2021
Noakhali Science & Technology University
Sonapur, Noakhali -3814
Department of Fisheries and Marine Science

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INDEX OF THE ASSIGNMENT
SL NAME OF CONTENTS PAGE
1 Introduction 3
2 What is Fin fish ? 3
3 What is Shell fish ? 4
4 Breeding Biology and Parameters of Finfish 6
5 Reproductive Biology of IMC’s 14
6 Breeding Biology of Penaeid Shrimps and Prawns: 15
7 Breeding Biology of Crabs 21
8 Reproductive Biology & Physiology of Lobsters: 24
9 Conclusion 25
10 References 26

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Breeding Biology and Parameters of Finfish and Shellfish
Introduction:
Reproduction is a fundamental biological process which enables continuation of species. In
fisheries biology, reproduction assumes greater significance to understand sexual
dimorphism, process of maturation, size or age of maturity, breeding season, spawning
area, sexual segregation, migration, fecundity, embryonic and larval development and
recruitment. Most of the management strategies in capture fisheries are based
on reference points that are the manifestations of reproductive biology. In aquaculture,
knowledge of reproductive biology of a fish is essential for hatchery production of fish
feeds.
What is Fin fish ?
Fins are usually the most distinctive anatomical features of a fish. They are composed of
bony spines or rays protruding from the body with skin covering them and joining them
together, either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as
seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with
the spine and are supported only by muscles. Their principal function is to help the
fish swim.
Fig : Ray fins on a teleost fish, Hector's lanternfish (1) pectoral fins (paired), (2) pelvic fins (paired),
(3) dorsal fin, (4) adipose fin, (5) anal fin, (6) caudal (tail) fin

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Fins located in different places on the fish serve different purposes such as moving
forward, turning, keeping an upright position or stopping. Most fish use fins when
swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins
can also be used for other purposes; male sharks and mosquitofish use a modified fin to
deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines
in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a
fishing rod to lure prey, and triggerfish avoid predators by squeezing into coral crevices
and using spines in their fins to lock themselves in place.
What is Shellfish ?
Shell fish is a colloquial and fisheries term for exoskeleton bearing aquatic invertibrates
used as food,including various species of molluscs,crustacean and echinoderms.Although
most kind of shellfish are hervested from salt water environments,some are found in fresh
water.In addition ,a few species of land crabs are eaten for example Cardisoma guanhumi in
the Caribbean. Shellfish are among the most common food allergens.
Fig: Marine Shirmp & fresh water prawn
Despite the name, shellfish are not fish. Most shellfish are low on the food chain and eat a
diet composed primarily of phytoplankton and zooplankton. Many varieties of shellfish,
and crustaceans in particular, are actually closely related to insects and arachnids;
crustacean make up one of the main subphyla of the Arthopoda .Molluscs include
cephalopods (squids, octopuses, cuttlefish) and bivalves (clams, oysters), as well

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as gastropods (aquatic species such as whelks and winkles; land species such as snails and
slugs). Molluscs used as a food source by humans include many species of
clam,mussels,oysters, winkles, and scallops. Some crustaceans that arecommonly eaten
are shrimp, lobsters, crayfish, and crabs. Echinoderms are not as frequently harvested for
food as molluscs and crustaceans; however, sea urchin roe is quite popular in many parts of
the world, where the live delicacy is harder to transport.
Fig ; Some Examples of shellfish

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Breeding Biology and Parameters of Finfish
1.Natural breeding of finfishes :
Most teleosts are seasonal breeders and their spawning coincides with seasonal
changes in environmental factors.
In response to environmental stimuli, the hypothalamus secretes a hormone termed
as releasing hormone (RH).
The Nucleus Lateralis Tuberis (NLT) of the hypothalamus responds to an electrical
signal from the brain by secreting RH at the end of the axon; thus an electric signal
becomes a chemical one (bridging the gap between nervous/neural and hormonal
information).
The arrangement of these neurons/axons is unique in teleosts, their axon directly
end on gonadotropic cells in the adenohypophysis, but do not secrete their
hormones into a portal blood system.
However, the effect of RH is to stimulate the production of Gonadotropic hormone
(GtH) and its subsequent release into the vascular system of the adenohypophysis.
GtH is then carried in the general blood circulation to the gonads which in turn
secrete steroids which are required for final maturation and spawning.
The chain of events leading from the reception of environmental stimuli to maturation and
release of gametes is as follows:

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2.Sexual maturity
 Maturation of fish gonads (gonadal maturation) is a process by which minute sex
cells (germ cells) develop, with accessory tissues, into large organs (testis and
ovary) which finally lead to the maturation and release of gametes (sperm and
eggs).
 Maturation may occur once in the life spawn of a fish or once a year or many times a
year, depending on species and conditions.
 Age at sexual maturity in fish varies with climatic and ecological /environmental
conditions. It varies between species and between sexes. In general, males mature
earlier than females.
 Size at first sexual maturity also varies with species and between sexes.
3.Breeding season
 The cultivated carps (with the exception of common carp) attain maturity at the end
of second year or the beginning of third year, depending upon the temperature.
 They mature during May-June and some are found to remain mature till the end of
August.
 Majority of the major carps breed during south-west monsoon, in flooded rivers.
 The common carp attains maturity at 4-6 months of age and breed year-round in
captivity.
 Like the common carp, tilapia matures at 4-5 months and spawns through out the
year.
 Medium carps, catfishes, murrels, etc. mature during pre-monsoon and with the
onset of South-West monsoon and breed in ponds, tanks, paddy fields, etc.
 Brackish-water and marine fishes attain maturity during pre-monsoon and with the
onset of South-West monsoon and have prolonged breeding season.
 Gonadotropins regulate the formation and maturation of gametes indirectly through
steroid hormones produced by gonad itself.

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Although there are rare cases of parthenogenesis, such as in the Amazon molly (Poecilia
formosa), the large majority of teleosts reproduce through sexual reproduction.
4.Number of Breeding Opportunity
Synchronous: Synchronous fish reproduce only once each year, or once in their lifetime. In
such species, all oocytes develop simultaneously and are at the same developmental stage
at a given time. This is the case for salmonids, for example. Eggs are spawned and the fish
dies -Pacific salmon
Group synchronous: Group synchronous fish have two or more distinct populations of
oocytes present at the same time and ovulate once in a season, or undergo multiple
ovulations over a few days or weeks within the spawning season.-Most species of fish
Asynchronous: Asynchronous fish, such as the zebrafish, are capable of ovulating on a
regular basis, sometimes every day, over a prolonged period.
5. Size and Age at First Maturation
Under different geographical and ecological conditions, the maturity age of the same
species is widely different. The maturity age of common carp is one year, for gross carp and
silver carp 2+ years and in case of Indian major carps such as Mrigal and Rohu the maturity
age is 1+ years while for catla 2+ years. However, in the same region maturity age varies
somehow rather with ecological conditions and other intrinsic factor. The induced breed
species reared in pond culture practice gets early maturity than the natural riverine stock.
Generally males mature little earlier than the female, in cultivable carps.
6. Time of Spawning and Duration/Season of Reproduction
The regular monsoon season (July-August) is the breeding season for the 5 cultivable carps
viz., Catla, Rohu, mrigal, silver carp and grass carp, in most part of India. However, the
season may begin a few months earlier or last longer depending upon the setting in of the
monsoon season, early or late in respective regions of the country, e.g. the breeding season
for carp’s starts earlier in Assam than in Orissa or Bengal. All the above carp species are

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more difficult to spawn than common carp. The common carp breeds in ponds and has two
breeding seasons on the plains of India viz. monsoon and post-winter period i.e. Feb. -
March. The major Indian and Chinese carps breed naturally in flooded river conditions
during monsoon in their native countries and this is also the suitable season for taking up
the induced breeding operation.
 CARPS (IMC): April to Sept. – During monsoon
 Common carp: 1-Feb-March; 2-August-sept
 Grass & Silver carp: April to Sept. – During monsoon
 Catfish(s) : During monsoon period
7. Type of Spawning
Open substrate spawner
Pelagic spawner: Benthic spawner:
A species that sheds pelagic eggs into the
water column .The eggs, embryos and larvae
of pelagic spawners contain oil globules or
have a high water content. They are usually
pelagic fish such as tuna and sardines. Some
demersal fish leave the bottom to spawn
pelagically, particularly coral reef fish such
as parrotfish .
Benthic spawners deposit their spawn on or
near the bottom. They are usually demersal
fish such as cod and flatfish
Brood hider
Brood hiders hide their eggs but do not give parental care after they have hidden them.
Brood hiders are mostly benthic spawners that bury the fertilized eggs. For example,
among salmon and trout the female digs a nest with her tail in gravel. These nests are
called redds. The female then lays her eggs while the male fertilizes them, while both fish
defend the redd if necessary from other members of the same species. Then the female

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buries the nest, and the nest site is abandoned. Annual killifish known as egg buriers lay
their eggs in mud. The parents mature quickly and lay their eggs before dying when the
water dries up. The eggs remain in a dormant stage until rains stimulate hatching.
Bearers
Bearers are fish that carry their embryos around with them, either externally or internally.
External bearers:
Mouth brooders - carry eggs or larvae in their mouth. Mouth brooders can be ovophiles or
larvophiles. Ovophile or egg-loving mouth-brooders lay their eggs in a pit, which are
sucked up into the mouth of the female. The small number of large eggs hatch in the
mother's mouth, and the fry remain there for a period of time. Fertilization often occurs
with the help of egg-spots, which are colourful spots on the anal fin of the male. When the
female sees these spots, she tries to pick up the eggspots, but instead gets sperm that
fertilizes the eggs in her mouth. Many cichlids and some labyrinth fish are ovophile
mouthbrooders. Larvophile or larvae-loving mouth-brooders lay their eggs on a substrate
and guard them until the eggs hatch. After hatching, the female picks up the fry and keeps
them in her mouth. When the fry can fend for themselves, they are released. Some
eartheaters are larvophile mouthbrooders.
Internal bearers:
The shorter times spwans are characteristic of species that eventually deposit their
embryos in the environment, surrounded by a horny capsule; whereas the longer periods
are characteristic of sharks that retain the embryos until they are ready to emerge as
actively swimming young. Fishes can be classified in to 5 groups on the basis of spawning.
 Lithophils: Fishes which spawn on hard stony surface eg. Salmon.
 Phytophils: Fishes which lag eggs among aquatic plants e.g. carp (Common carp)
 Psammophils: Fishes which deposit eggs in sandy surface e.g. Loach.
 Ostracophils: Fishes which deposit eggs inside a bivalve e.g. Chilogolsio.

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 Pelagophils: Fishes which spawn freely in column of water and the eggs float (cod
fish)
8. Mating System
Promiscuous mating system : Promiscuous is a mating system where both sexes have
multiple partners during the breeding system (e.g. Herring, Cod). In fishes, this is the most
common mating system. Breeders make little or no mate choice and spawn with multiple
partners, either sequentially or at the same time.
Polygamous mating system: Polygamous is a mating system in which an individual of one
sex has multiple partners during the breeding system but individuals of the opposite sex
have only one partner (e.g. Sunfish, tilapia, catfish). Evolutionarily, these systems are
purported to have an increased chance of passing on “good genes” from individuals that
compete for the ability to mate with multiple partners. This mating system can occur with
one male and many females (polygyny) or one female and multiple males (polyandry)
9.Gender System
Gonochoristic: In biology, gonochorism or unisexualism or gonochory describes the state
of having just one of at least two distinct sexes in any one individual organism. The term is
most often used with fish, in which the individual are often gonochorous.
Hermaphroditic: Fish that, when mature, possess both male (testes) and female (ovary)
sex glands at the same time. In such species cross-fertilization can occur during spawning.
Most Serranidae (sea perches) are females first or have both sets of glands equally
developed. Sex may change after maturation (e.g. Sea bream)

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10.Spawning Site Preparation
 No preparation; most spp. of broadcast spawners
 Site preparation and defended; Tilapia, salmons
11. Place of Fertilization
External: External fertilization usually occurs in aquatic environments where both eggs
and sperm are released into the water. After the sperm reaches the egg, fertilization can
then take place. Most external fertilization happens during the process of spawning where
one or several females release their eggs and the male(s) release sperm in the same area, at
the same time.
Internal: Internal fertilization occurs most often in landbased animals, although some
fishes also have internal fertilization. There are three ways that offspring are produced
following internal fertilization: oviparity, ovoviparity, and viviparity.
Oviparity: Ovuliparity means the female lays unfertilized eggs (ova), which are externally
fertilized.Examples of ovuliparous fish include salmon, goldfish, cichlids, tuna and eels. In
the majority of these species, fertilisation takes place outside the mother's body, with the
male and female fish shedding their gametes into the surrounding water.
Ovoviviparity: In ovoviviparous fish the eggs develop inside the mother's body after
internal fertilisation but receive little or no nourishment directly from the mother,
depending instead on a food reserve inside the egg, the yolk. Each embryo develops in its
own egg. Familiar examples of ovoviviparous fish include guppies, angel sharks, and
coelacanths.
Viviparity: Viviparity occurs in some Sharks and Surf - perches. Similar to ovoviviparous
fish, internal fertilization and development occurs. However, the embryos receive direct
nourishment from the mother, similar to the development of an embryo in mammals. Like
ovoviviparous fish, the viviparous fish give birth to live young, however viviparous fish are
fully advanced at birth allowing for a greater chance of survival

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12. Mechanism of Hatching
There are two mechanisms involved in hatching such as: (a) mechanical hatching and (b)
enzymatic hatching
A. Mechanical Hatching: The mechanical hatching is a process in which egg envelopes are
broken down primarily by mechanical action such as pressure exerted from within or
mastication by the embryo itself.
B. Enzymatic Hatching: In enzymatic hatching emergence of young occurs after
dissolution or softening of egg envelope by the enzymes secreted by the embryo. This
enzyme is called hatching enzyme. These enzymes are secreted into the perivilelline fluid at
the time of hatching from the hatching gland cell located in the epidermis of the embryo.
13. Parental Care
Parental care is a very important adaptation among fishes for ensuring the survival of their
offspring. The parent fish stock look after their offspring during their most critical stage of
life when they are defenseless and very sensitive parental care is of two types: Passive care
(ii) Active care.
(i) Passive care: This is actually the hereditary foresight of the female to provide more
yolk for embryo to sustain life for a long time or to place the eggs on such sites where the
optimum environmental conditions are met and beyond the reach of enemies. Some fish
have in their eggs a poisonous substance which keeps predators away e.g. all major carps.
Fish with passive care have high number of eggs .
(ii) Active care:In active parental care either one or both of the parents take an active part
in carrying for and defending their eggs, larvae and sometimes the fry as well. This
includes the selection and preparation of a suitable place for depositing the eggs, selection
of a good substrate to which the eggs can adhere, collection of nest making material and

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preparation of the nest e.g. Tilapia, fighter etc. Fish with active care have normally less no.
of eggs.
Reproductive Biology of IMC’s
Sexuality: All the major carps species are bisexual (hetro-sexual) and sex can be
distinguished only during the breeding season. The identifying features between sexes are
related to the length and texture of pectoral fin, condition of genital aperture and size of the
belly.
Pectoral Fin: The pectoral fin of male has rough dorsal surface and the same is
longer than that of female. In female dorsal side of pectoral fin is smooth.
Genital Aperture: In female it is radish and swollen whereas in male the same is
not prominent. Further on applying gentle pressure, milt oozes out through the
genial aperture in male, but in female eggs ooze out.
Shape of the Belly: Belly of the female is soft swollen and bulging which is not
found is male.
Age and Size at First Sexual Maturity: Age and size at first sexual maturity of a given
species may vary depending on the temperature and other environmental factors.
Generally, all the 3 major carps attain sexual maturity in the second year and the males
mature earlier than female. The females grow faster than male and hence usually, the males
are smaller than female in a given population of the same age group. Hence carps of 2+
years and upto 5 years are preferred for breeding. After 5 years fecundity sets in and hence
is not advised to use for breeding.
Spawning Season: All the 3 major carps are seasonal riverine spawners, spawning during
the southwest monsoon months (June to August). They spawn in inundated shallow areas
adjacent to the river during floods. They do not breed usually in the first flood but breeding
during middle and later parts of monsoon. They do not spawn in confined waters.

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Fecundity: Fecundity in Catla has been reported to vary from 1.66 to 2.03 lacs per kg body
weight, in rohu it is reported to vary from 3.45 to 3.82 lacs per kg body weight and in
mrigal it is in range of 1.39 to 1.87 lacs per kg body wt. Thus out of 3 carps, rohu has
greater fecundity than the other two carps. The size of the water hardened eggs also varies
in three carps – largest size being in mrigal (20,000 Nos/ lit of water) and smallest being
that of rohu (30,000 Nos/lit of water). In catla 25000 eggs are usually found in one liter of
water hardened egg.
Breeding Biology of Shellfish
Reproductive Biology of Penaeid Shrimps and Prawns:
1.Age and Size :
Age at first breeding of tiger shrimp is not clearly established. It is reported that a
combination of age and body size along with feed availabe and favourable environmental
conditions influence the onset of sexual maturity. Nevertheless, the size is a matter for the
high fecundity and yield of good young ones.The males of body weight between 40 and 70g
and females with body weight of 60 to 80g are found sexually matured among wild stock,
whereas among farm reared shrimps, male weighing 35g and females weighing 40g are
found sexually matured. Other contributing factors might be resposnisble for differnce in
maturity.

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2.Sexual Demorphsm
Male Female
Presence of petasma in the 1st pleopod. Petasma is absent in the 1st pleopod in
female.
Presence of appendix masculina in the
2nd pleopod.
Appendix masculina is absent.
Thelycum is absent. Thelycum is present between pereopods IV
& V.
Gonopore is located at the base of
5th walking log.
Gonopore is located at the base of
3rd walking leg.
Smaller in size. Larger than male of the same age group
The male reproductive system
The male reproductive system consists of a pair of testes located in the cephalothorax (CT)
above the hepatopancreas (HP). The testes are translucent, composed of 6 lobes and all the
lobes are connected on the inner margin leading to vas deferens (vd). Vas deferens has 4
regions such as a proximal region, which is short and narrow, a medium portion which is
thick and larger, long narrow distal part and a muscular portion called terminal ampoule
which opens at the base of coxa of 5th perieopod. The gametes produced by the lobules of
testis are aggregated and stored in a bag and are called spermatophores, which are stored
in terminal ampoule. Spermatozoa of shrimps are small in size and lacks flagellum. Sperms
are immotile and attach to the egg at spike end.

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Fig: Macrobrachium sp. Reproductive system . A.Male. B.Female
The female reproductive system
There are a pair of ovaries which are partly fused extending almost the entire length of a
mature specimen. Each ovary consists of an anterior lobe, lateral lobes located dorsal to the
hepatopancreas and an abdominal lobe lying dorso-lateral to the intestine. The oviduct
originates from sixth lateral lobe, leading to the external genital papilla located at the base
of 3rd periopod.
Male reproductive organ-External Process
Male reproductive system externally consists of a pair of pleopods as accessory
reproductive organ, present on the inner side of the abdominal flap. The ejaculatory ducts
of the testes open into a small gential papilla at the base of the 3rd pair of the walking legs.

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The first pair of pleopod of the shrimp is made up of two segments, the basal one is broad,
rectangular and flattened and positioned close to the sternal wall and the terminal one is
long tube-like and tapering towards the tip. During mating with the female shrimp, this tip
is inserted into the seminal receptacle of the female.
The second pleopod helps in passing the spermatophores from the ejaculatory ducts into
the funnel-like portion of the first pleopod.The ejaculate from the gonad (testes) consists of
non-motile sperms and seminal plasma. Sperms are enclosed in numerous small
spermatophores and stored in the anterior vas deferens (vd), while the seminal plasma is
produced and stored in the posterior vas deferens.
Female reproductive organ - External
The female reproductive organ consists of a sperm receiving organ called Thelycum, which
is present in the middle portion of the last pair of the walking legs. There are two types of
Thelycum, namely closed thelycum and open thelycum based on the presence and absence
of the lateral plates in the thelycum, respectively.

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Maturity stages of ovary
In general the ovaries can be classified based on the maturity stages of the eggs. Broadly
the maturity stages are:
Immature: The ovaries in immatured female shrimps will be transparent / light yellowish
to ivory in colour; occupying 1/6th of body cavity; or like fili form. The Gonado
Somatic Index (GSI) at this stage will be strikingly low.
Maturing: Ovaries in maturing shrimps will be light to dark yellowish or orange in colour;
ovaries are filled with egg mass and therefore they will be occupying 1/3rd of body cavity.
Matured: Ovaries in matured females will be orange-red in colour; filled with matured
eggs with or without yolk granules. prominent seminal receptacle will be present;
occupying full body cavity and showing a high GSI. The females with matured ovary can be
identified by the presence of fully widened ovary in the body extending from cephalothorax
to the abdomen with prominent bulged portion in the ovary.

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Mating characteristics in open vs closed thelycum species
Penaeus species are grouped into two broad categories based on differences in morphology
of the female genital organ or thelycum which occupies the area from the third to the fifth
periopods. The “open thelycum” species include the members of
the Litopenaeus subgenera. They receive spermatophore or sperm packet from the male
and retain it externally for a few hours perior to spawning.
In contrast, the “closed thelycum” species are those which mate each time the female molts.
The closed thelycum female receives the spermatophore into her thelycum and then her
new exoskeleton gets hardened over it. She retains the spermatophore until she utilizes the
sperm in one or several spawning. The subgenera Penaeus, Fenneropenaues, Marsupenaeus
and Melicrotus have the closed or internal type thelycum.
This open thelycum females follow a sequence of molt-mature- mate and spawn while
closed thelycum species follow a sequence of molt- mate-mature and spawn. In both
groups, males with hard exoskeleton deposit spermatophores into females. Multiple
spawns may occur within one intermolt period for both open and closed thelycum speices.
The stimulus for courtship behaviour in Penaeus sp. is believed to be motivated by the sex
pheromone secreted in the females and received by the males through their antennules or
antennular flagella. In open thelycum species, mating occurs mainly in the evening and in
the night spawning will occur.

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Reproductive systems of male and female prawns
The male reproductive system of freshwater prawn consists of a pair of testes united at the
anterior end. It is located within the cephalothorax region of the male.
The female reproducitve system consists of a massive ovary situated in the cepahlothorax
region. The ovary can be clearly seen from the dorsal side of the body in the CT region as a
yellow coloured mass. The oviduct arising from the ovary opens outside in the base of the
3rd walking leg. The seminal receptacles are present in the exterior of the female genital
openings situated in the left and right sternites of sixth thoracic segment.
Externally four pairs of pleopods serve as accessory reproductive organs present on the
inner side of the second to fifth segments of the abdominal flap. Each pleopod consists of a
basal propodite from which arise the medial endopodite and lateral exopodite. The
exopodite bears a large number of pinnate setae. A cluster of long and very smooth setae
are on the endopodite, to which the extruded eggs are attached at the time of spawning .
Reproductive Biology of Crabs
1.Identification of sexes : Sexes can be morphologically distinguished based on the
shape of the abdominal flap. Though the shape of this flap is similar in both immature and
mature male, it is different in mature and immature female. In mature female the shape of
abdominal flap is half-round, while in immature female it is broad and triangular.
2.Sexual dimorphism : The sexes are separate and there is distinct sexual dimorphism
in crabs: Distinction between male & female based on morphological characters.

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Male Female
Abdominal flap which is folded firmly
against the ventral side is narrow (triangle
shape) of cephalothorax is slender and
triangular.
Appendages are present only on 1st and
2nd abdominal segments and the same are
modified to copulatory organs.
The claws are comparatively larger.
Abdominal flap folded against the ventral
side of body is broad (Round shape) and
berried females.
There are 4 pairs of abdominal
appendages present from 2nd to
5th segment and the same are used for
carrying the eggs.
The claws are smaller.
3.Size and maturity: The size range at first maturity in males and females of S.
tranquebarica and S. serrata is presented in the Table below:
Size range at first maturity in S. tranquebarica and S. serrata
Species Sex
Size range at first maturity
(Carapace width in mm)
S.tranquebarica
S.serrata
Male
Female
Male
Female
125-133
129-135
80-89
85-96
4.Mating: The size at first sexual maturity is 120 mm (carapace width) for larger species
(S.tranquebarica) and 83 mm (cw) for S. serrata. The early maturing ovary is bright orange
in colour where as, in matured – ready to spawn female, it is deep yellow in colour.
Copulation takes place between a hard shelled male and a freshly moulted, soft bodied

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female. The courtship is initiated by a “premating embrace” between hard shelled male and
hard shelled female which lasts for 2-3 days
5.Spawning: The ova are extruded by the female and the same are fertilized by the
sperm stored in the spematophores. The fertilized eggs are attached to the ovigerous setae
of the abdominal appendages. In S. tranquebarica, the nos. of eggs may be 2-3 million per
female of body weight whereas in S. serrata it is 0.5-2.5 million such as females with eggs
attached to the abdomen are called berried.
6.Incubation & hatching : The berried females carry their eggs for 2 weeks, during
which period the embryos develop. The eggs undergo change of colour from orange to grey
/ brown. Just before releasing the larvae, the eggs become grey black. After the incubation
period, the larvae hatch out. The hatched out larvae need feed for their growth.

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Reproductive Biology & Physiology of Lobsters:
Spiny lobsters are abundant in Gulf of Kutch, Maharastra,Gulf of Mannar and Andaman
Nicobar islands. It is a valuable fishery resource for the country as it brings in huge foreign
exchange and a much demanded sea food in the world. In recent years there has been a
decline in the catch due to over- exploitation of juveniles and spawning females. It is
necessary to protect this valuable resource by artificial seed production and ranching. This
has been emphasized by many natural and biological researchers in the world.
There are many bottle necks in the hatchery seed production of lobsters. However,
constantly efforts are being made to overcome the bottle necks and make the seed
production possible. Clear understanding of the basic reproductive biology and physiology
of lobsters is essential to make success in the seed production.
1.Sexual dimorphism
Sexes are separate in lobsters and usually males are larger than females. In the male, the
5th periopod or walking leg ends in single claws but in the female the tips of these legs are

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provided with three points formed by spurs used for carrying eggs attched to the under
side of the tail.
2.Identification of males and females
The males differ by the presence of swollen genital opening at the base of last pair of
periopod, whereas in the females it opens at the base of 3rd pair of periopod or walking
legs. The female lobsters have two branches of swimming legs whereas the male is having a
single branch. The animal has a prolonged breeding periopod and the peak season is
October- December under natural condition but it is observed that in confined conditions,
it breeds throughout the year in India.
3.Mating and spawning
Male lobster deposits spermatophores on the sternum of the female between the last three
pairs of appendages. The spermatophores turn black and are called as tar spots.
Development of eggs will take 24-72 hrs, during this periopod eggs will develop and
remain attached with pleopods of female lobster or oveigerous setae. The female carries
the eggs until the hatch out.
Conclusion:
Fish genetic breeding is a process that remolds heritable traits to obtain neotype and
improved varieties. For the purpose of genetic improvement, researchers can select for
desirable genetic traits, integrate a suite of traits from different donors, or alter the innate
genetic traits of a species. These improved varieties have, in many cases, facilitated the
development of the aquaculture industry by lowering costs and increasing both quality and
yield. The pertinent literatures and summarize the biological bases and application of
selection breeding technologies (containing traditional selective breeding, molecular
marker-assisted breeding, genome-wide selective breeding and breeding by controlling
single-sex groups), integration breeding technologies (containing cross breeding, nuclear

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transplantation, germline stem cells and germ cells transplantation, artificial gynogenesis,
artificial androgenesis and polyploid breeding) and modification breeding technologies
(represented by transgenic breeding) in fish genetic breeding.
References:
[ 1 ] http://ecoursesonline.iasri.res.in/course/view.php?id=585
[2]https://www.researchgate.net/publication/305329627_Methodologies_for_studying_fi
nfish_and_shellfish_biology
[ 3 ] https://en.wikipedia.org/wiki/Shellfish
[ 4 ] https://en.wikipedia.org/wiki/Fish_fin
[ 5 ] https://www.slideshare.net/KartikMondal1/finfish-breeding-and-hatchery-
management-61758258