Search results
Results From The WOW.Com Content Network
Ovuliparity means the female lays unfertilised eggs (ova), which must then be externally fertilised. [10] 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 ...
Protogyny is the most common form of hermaphroditism in fish in nature. [30] About 75% of the 500 known sequentially hermaphroditic fish species are protogynous and often have polygynous mating systems. [31] [32] In these systems, large males use aggressive territorial defense to dominate female mating.
Choosing species to use requires consideration of the biology of the species. This includes their size at maturity, method of reproduction, feeding behaviour and ability to tolerate adverse conditions [9] Farms also consider whether they grow their own broodstock or obtain them from natural populations. Where natural populations are excluded ...
Epilobium hirsutum — Seed head. In the broadest sense, dispersal occurs when the fitness benefits of moving outweigh the costs. There are a number of benefits to dispersal such as locating new resources, escaping unfavorable conditions, avoiding competing with siblings, and avoiding breeding with closely related individuals which could lead to inbreeding depression.
The surfperch, genus Embiotoca, is a saltwater fish with a gestation period of three to six months. [13] This lengthy period of pregnancy gives the family its scientific name from the Greek "embios" meaning "persistent" and "tokos" meaning "birth". The table below shows the gestation period and number of young born for some selected fish.
Breeding pair, bonded animals who cooperate to produce offspring; Breeding program, a planned breeding of animals or plants; Breeding season, the period during each year when a species reproduces; Captive breeding, raising plants or animals in zoos or other controlled conditions; Cooperative breeding, the raising of the young using non-parental ...
In fish breeding, those parents frequently are two closely related fish species, while in plant and animal breeding, the parents often are two inbred lines. Gregor Mendel focused on patterns of inheritance and the genetic basis for variation .
Nuptial tubercles or breeding tubercles (also called pearl organs or nuptial efflorescence) are noticeable skin roughness or horny nodules that form on male fish during breeding. They are made of keratin, the same material as hair, hooves, and fingernails.