Difference between revisions of "Fish Reproduction - Anatomy & Physiology"
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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 are several categories which can be used to divide fish into reproductively similar groups as follows: | 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 are several categories which can be used to divide fish into reproductively similar groups as follows: | ||
| − | == Dioecism, | + | == Dioecism, Parthenogenesis & Hermaphrodism == |
| + | |||
| + | === 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 === | ||
| + | |||
| + | * An asexual form of reproduction found in females where growth and development of embryos occurs without fertilization by males. | ||
| + | 100% female contribution. | ||
| + | Self-activated oocytes require no contribution from sperm. | ||
| + | The offspring produced by parthenogenesis almost always are female in species where the XY chromosome system determines gender. | ||
| + | |||
| + | === Hermaphrodism === | ||
== Monogamy, Polygyny, Polyandry & Polygynandry == | == Monogamy, Polygyny, Polyandry & Polygynandry == | ||
Revision as of 11:21, 29 July 2008
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 are several categories which can be used to divide fish into reproductively similar groups as follows:
Dioecism, Parthenogenesis & Hermaphrodism
Dioecism
- The majority of fish are Dioecious (a species that possesses both males and females in separate bodies).
Parthenogenesis
- An asexual form of reproduction found in females where growth and development of embryos occurs without fertilization by males.
100% female contribution. Self-activated oocytes require no contribution from sperm. The offspring produced by parthenogenesis almost always are female in species where the XY chromosome system determines gender.