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Fish Reproduction - Anatomy & Physiology (view source)
Revision as of 13:14, 3 September 2008
, 13:14, 3 September 2008no edit summary
{{toplink
|backcolour =EED2EE
|linkpage =Reproductive System - Anatomy & Physiology
|linktext =Reproductive System
|maplink = Reproductive System (Content Map) - Anatomy & Physiology
= Introduction =
|pagetype =Anatomy
|sublink1=Reproductive System - Anatomy & Physiology#Exotics
|subtext1=EXOTICS
}}
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== Introduction ==
There is great diversity in the reproductive systems of fish. Some produce eggs and sperm for external fertilization, while others copulate with the discharge of either fertilized eggs or young fish.
There is great diversity in the reproductive systems of fish. Some produce eggs and sperm for external fertilization, while others copulate with the discharge of either fertilized eggs or young fish.
= Male =
== Male ==
== Testes ==
=== Testes ===
* Most species have paired, intra-abdominal testes.
* Most species have paired, intra-abdominal testes.
* No lymphatics of the type seen in mammals.
* No lymphatics of the type seen in mammals.
= Female =
== Female ==
== Ovaries ==
=== Ovaries ===
* Paired
* Paired
** Hyaline zone forms between the oocyte and the epithelial cells - the zona pellucida.
** Hyaline zone forms between the oocyte and the epithelial cells - the zona pellucida.
== Oviduct ==
=== Oviduct ===
=== Gymnovarian ===
==== Gymnovarian ====
* Primative
* Primative
* Travel through the [[Female_Reproductive_Tract_-The_Oviduct_-_Anatomy_%26_Physiology|oviduct]] and are eliminated.
* Travel through the [[Female_Reproductive_Tract_-The_Oviduct_-_Anatomy_%26_Physiology|oviduct]] and are eliminated.
=== Secondary Gymnovarian ===
==== Secondary Gymnovarian ====
* Salmonids and a few other teleosts.
* Salmonids and a few other teleosts.
* Go directly into the [[Female_Reproductive_Tract_-The_Oviduct_-_Anatomy_%26_Physiology|oviduct]].
* Go directly into the [[Female_Reproductive_Tract_-The_Oviduct_-_Anatomy_%26_Physiology|oviduct]].
=== Cystovarian ===
==== Cystovarian ====
* Most teleosts
* Most teleosts
** Ovarian lumen is continuous with the ovarian duct.
** Ovarian lumen is continuous with the ovarian duct.
=== Post-Oocyte release ===
==== Post-Oocyte release ====
* Postovulatory [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicles]] are formed after [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocyte]] release
* Postovulatory [[The_Ovary_-_Follicles_-_Anatomy_%26_Physiology|follicles]] are formed after [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocyte]] release
** This process can also occur, but less frequently, in [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocytes]] in other development stages.
** This process can also occur, but less frequently, in [[The_Ovary_-_Oocytes_-_Anatomy_%26_Physiology|oocytes]] in other development stages.
== Oviparity ==
=== Oviparity ===
* 97% of fish
* 97% of fish
*** During this transition larvae use up their yolk sac and must switch from yolk sac nutrition to feeding on zooplankton prey.
*** During this transition larvae use up their yolk sac and must switch from yolk sac nutrition to feeding on zooplankton prey.
== Ovoviviparity ==
=== Ovoviviparity ===
* Examples include guppies, angel sharks, and coelacanths.
* Examples include guppies, angel sharks, and coelacanths.
* Each embryo develops in its own egg.
* Each embryo develops in its own egg.
== Viviparity ==
=== Viviparity ===
* Very rare
* Very rare
** Found in some sharks.
** Found in some sharks.
= Stages of Reproduction =
== Stages of Reproduction ==
== Oocyte Development ==
=== Oocyte Development ===
* Gonadotrophin independent
* Gonadotrophin independent
* Dependent on body size
* Dependent on body size
== Vitellogenesis ==
=== Vitellogenesis ===
* Production of the yolk
* Production of the yolk
* Longest phase of reproduction
* Longest phase of reproduction
== Oocyte Maturation ==
=== Oocyte Maturation ===
== Spawning ==
=== Spawning ===
* Release of eggs and sperm
* Release of eggs and sperm
* Mating behaviour displayed
* Mating behaviour displayed
== Recovery ==
=== Recovery ===
* Body condition restored
* Body condition restored
* New oocyte developement
* New oocyte developement
= Breeding Cycles =
== Breeding Cycles ==
* Vary from 4 weeks - many years.
* Vary from 4 weeks - many years.
* Some species only breed once in a lifetime (Pacific Salmon).
* Some species only breed once in a lifetime (Pacific Salmon).
= Reproductive Endocrinology =
== Reproductive Endocrinology ==
In fish, as with all higher animals, [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|hormones]] play a critical role in the reproductive process. [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|Hormones]] are chemical messengers released into the blood by specific tissues, such as the [[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]]. The [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|hormones]] travel through the bloodstream to other tissues, which respond in a variety of ways. One response is to release another [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|hormone]], which elicits a response in yet another tissue. The primary tissues involved in this hormonal cascade are the [[Endocrine_System_-_Hypothalamus_-_Anatomy_%26_Physiology|hypothalamus]],[[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]], and gonads.
In fish, as with all higher animals, [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|hormones]] play a critical role in the reproductive process. [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|Hormones]] are chemical messengers released into the blood by specific tissues, such as the [[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]]. The [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|hormones]] travel through the bloodstream to other tissues, which respond in a variety of ways. One response is to release another [[Endocrine_System_-_Hormones_-_Anatomy_%26_Physiology|hormone]], which elicits a response in yet another tissue. The primary tissues involved in this hormonal cascade are the [[Endocrine_System_-_Hypothalamus_-_Anatomy_%26_Physiology|hypothalamus]],[[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]], and gonads.
* Following [[The_Ovary_-_Ovulation_-_Anatomy_%26_Physiology|ovulation]], the viability of the eggs can decrease rapidly.
* Following [[The_Ovary_-_Ovulation_-_Anatomy_%26_Physiology|ovulation]], the viability of the eggs can decrease rapidly.
= Sex Determination =
== Sex Determination ==
== Genetic ==
=== Genetic ===
=== Sex Chromosome Dependent ===
==== Sex Chromosome Dependent ====
* 10% of fish
* 10% of fish
* Some variations to this may be seen.
* Some variations to this may be seen.
=== Autosome Dependent ===
==== Autosome Dependent ====
* Autosomes have sex determining factors
* Autosomes have sex determining factors
== Temperature Dependent ==
=== Temperature Dependent ===
* Some species of fish
* Some species of fish
= Dioecism, Parthenogenesis & Hermaphrodism =
== Dioecism, Parthenogenesis & Hermaphrodism ==
== Dioecism ==
=== Dioecism ===
* The majority of fish are '''Dioecious''' (a species that possesses both males and females in separate bodies).
* The majority of fish are '''Dioecious''' (a species that possesses both males and females in separate bodies).
== Parthenogenesis ==
=== Parthenogenesis ===
* An asexual form of reproduction found in females where growth and development of embryos occurs without fertilization by males.
* An asexual form of reproduction found in females where growth and development of embryos occurs without fertilization by males.
* Occurs in very few fish species.
* Occurs in very few fish species.
== Hermaphrodism ==
=== Hermaphrodism ===
Hermaphroditic species can be either simultaneously hermaphroditic or sequentially hermaphroditic.
Hermaphroditic species can be either simultaneously hermaphroditic or sequentially hermaphroditic.
=== Simultaneously Hermaphroditic Species ===
==== Simultaneously Hermaphroditic Species ====
* Sea Bass
* Sea Bass
* Ripening of the gonads may be sequential to prevent unnecessary self fertilization.
* Ripening of the gonads may be sequential to prevent unnecessary self fertilization.
=== Sequentially Hermaphroditic Species ===
==== Sequentially Hermaphroditic Species ====
* Any given individual is only one gender at a time, but can change gender when necessary.
* Any given individual is only one gender at a time, but can change gender when necessary.
** If the dominant male is removed, the most dominant female will become male.
** If the dominant male is removed, the most dominant female will become male.
= Monogamy, Polygyny, Polyandry & Polygynandry =
== Monogamy, Polygyny, Polyandry & Polygynandry ==
== Monogamy ==
=== Monogamy ===
* One male and one female form a pair bond for life, or at least for one reproductive season.
* One male and one female form a pair bond for life, or at least for one reproductive season.
* Rare in fish
* Rare in fish
* Mostly seen in Anemone and some Cichlid species.
* Mostly seen in Anemone and some Cichlid species.
== Polygymy ==
=== Polygymy ===
* One male and two or more females
* One male and two or more females
** Lekking is where all the males of an area gather together in a 'Lek' to display. Females visit the Lek, chose a male and leave with him to mate. The male returns to the 'Lek' after mating, and may then be chosen by another female. Thus lekking often results in Polygymy.
** Lekking is where all the males of an area gather together in a 'Lek' to display. Females visit the Lek, chose a male and leave with him to mate. The male returns to the 'Lek' after mating, and may then be chosen by another female. Thus lekking often results in Polygymy.
== Polyandry==
=== Polyandry===
* One female and more than one male
* One female and more than one male
* Very rare in fish
* Very rare in fish
== Polygynandry ==
=== Polygynandry ===
* Most common
* Most common
* Female may have her eggs fertilized by many males and a male may fertilize the eggs of many females.
* Female may have her eggs fertilized by many males and a male may fertilize the eggs of many females.
= Pelagic & Benthic Spawners =
== Pelagic & Benthic Spawners ==
Mass spawning is the most common method of reproduction in fish. It involves all the members of a particular species in a particular area getting together in a single place to release sperm and eggs together. Number of sperm produced by a single male fish is normally billions, to increase the chance of fertilization occuring. Sperm can survive in the environment of the water for a period of time to allow external fertilization. Species that use this method include Tuna, Sardines, Pilchards, Cod, Mackeral, Pollack, Hake, Tailor, Halibut, Eels, Herring and Menhaden.
Mass spawning is the most common method of reproduction in fish. It involves all the members of a particular species in a particular area getting together in a single place to release sperm and eggs together. Number of sperm produced by a single male fish is normally billions, to increase the chance of fertilization occuring. Sperm can survive in the environment of the water for a period of time to allow external fertilization. Species that use this method include Tuna, Sardines, Pilchards, Cod, Mackeral, Pollack, Hake, Tailor, Halibut, Eels, Herring and Menhaden.
== Pelagic Spawners ==
=== Pelagic Spawners ===
* Eggs released into surrounding water.
* Eggs released into surrounding water.
* Eggs are carried along by the currents.
* Eggs are carried along by the currents.
== Benthic Spawners ==
=== Benthic Spawners ===
* Pike and many Carp
* Pike and many Carp
** May be small and rapidly take on water, trapping themselves in small crevasses.
** May be small and rapidly take on water, trapping themselves in small crevasses.
= Bearers, Guarders and Non-Guarders =
== Bearers, Guarders and Non-Guarders ==
== Bearers ==
=== Bearers ===
* One parent carries the eggs until they hatch.
* One parent carries the eggs until they hatch.
== Guarders ==
=== Guarders ===
* Guard the eggs
* Guard the eggs
= [[Exotics - Fish Inducing Reproduction - Anatomy & Physiology|Inducing Reproduction]] =
== [[Exotics - Fish Inducing Reproduction - Anatomy & Physiology|Inducing Reproduction]] ==