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Intrasexual Competition
Male-male intrasexual competition occurs when two males of the same species compete for the opportunity to mate with a female. Sexually dimorphic traits, size, sex ratio, and the social situation may all play a role in the effects male-male competition has on the reproductive success of a male and the mate choice of a female. Larger males tend to win male-male conflicts due to their sheer strength and ability to ward off other males from taking over their females. For instance, in the fly '' Dryomyza anilis'', size shows the strongest correlation to the outcome of male-male conflicts over resources like territory and females. Influencing factors Sex ratio There are multiple types of male-male competition that may occur in a population at different times depending on the conditions. Competition variation occurs based on the frequency of various mating behaviours present in the population. One factor that can influence the type of competition observed is the population density o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mate Choice
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choice, Cambridge University Press, 1985 In other words, before an animal engages with a potential mate, they first evaluate various aspects of that mate which are indicative of quality—such as the resources or phenotypes they have—and evaluate whether or not those particular trait(s) are somehow beneficial to them. The evaluation will then incur a response of some sort. These mechanisms are a part of evolutionary change because they operate in a way that causes the qualities that are desired in a mate to be more frequently passed on to each generation over time. For example, if female peacocks desire mates who have a colourful plumage, then this trait will increase in frequency over time as male peacocks with a colourful plumage will hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dryomyza Anilis
''Dryomyza anilis'' is a common fly from the family Dryomyzidae. The fly is found through various areas in the Northern hemisphere and has brown and orange coloration with distinctive large red eyes. The life span of the fly is not known, but laboratory-reared males can live 28–178 days. ''D. anilis'' has recently been placed back in the genus ''Dryomyza'', of which it is the type species. ''Dryomyzidae'' were previously part of ''Sciomyzidae'' but are now considered a separate family with two subfamilies. Male ''D. anilis'' engage in territorial behavior, guarding carcasses to attract potential mates. Males also guard females, and conflicts over females are frequent. Females typically mate with multiple males. Mating occurs through several rounds of copulation and egg-laying. During mating, males engage in a series of "tapping" rituals where they use their claspers to tap the female's genitals, increasing the chance of them fertilizing the female's eggs. Females lay several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oryzias Latipes(Hamamatsu,Shizuoka,Japan,2007)-1
The Japanese rice fish (''Oryzias latipes''), also known as the medaka, is a member of genus ''Oryzias'' ( ricefish), the only genus in the subfamily Oryziinae. This small (up to about ) native of East Asia is a denizen of rice paddies, marshes, ponds, slow-moving streams and tide pools. It is euryhaline, occurring in both brackish and freshwater. It became popular as an aquarium fish because of its hardiness and pleasant coloration: its coloration varies from creamy-white to yellowish in the wild to white, creamy-yellow, or orange in aquarium-bred individuals. Bright yellow, red or green transgenic populations, similar to GloFish, have also been developed, but are banned from sale in the EU. The medaka has been a popular pet since the 17th century in Japan. After fertilization, the female carries her eggs attached anterior to the anal fin for a period before depositing them on plants or similar things. Ecology Medaka live in small ponds, shallow rivers, and rice fields. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japanese Rice Fish
The Japanese rice fish (''Oryzias latipes''), also known as the medaka, is a member of genus ''Oryzias'' ( ricefish), the only genus in the subfamily Oryziinae. This small (up to about ) native of East Asia is a denizen of rice paddies, marshes, ponds, slow-moving streams and tide pools. It is euryhaline, occurring in both brackish and freshwater. It became popular as an aquarium fish because of its hardiness and pleasant coloration: its coloration varies from creamy-white to yellowish in the wild to white, creamy-yellow, or orange in aquarium-bred individuals. Bright yellow, red or green transgenic populations, similar to GloFish, have also been developed, but are banned from sale in the EU. The medaka has been a popular pet since the 17th century in Japan. After fertilization, the female carries her eggs attached anterior to the anal fin for a period before depositing them on plants or similar things. Ecology Medaka live in small ponds, shallow rivers, and rice fields. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhacophorus Omeimontis
''Zhangixalus omeimontis'' is a species of frog in the family Rhacophoridae endemic to China. Its common name is Omei whipping frog or Omei treefrog, in reference to its type locality, Mount Emei () in Sichuan. It is found in southern and central China in Yunnan, Sichuan, Guangxi, Guizhou, Hunan, and Hubei provinces. It is a relatively common frog that inhabits forests, and sometimes farmland. It breeds in still water (pools and ponds). Agriculture and logging are threats to this species. Description ''Zhangixalus omeimontis'' are moderately large frogs: males grow to a snout–vent length of about and females to . Maximum sizes can be even higher, reaching at least in males and in females. They tend to be bigger and older at cooler sites (i.e., at higher altitudes). Maximum age is at least eight years. Tadpoles are up to in length. Reproduction ''Zhangixalus omeimontis'' breed between mid-April and late July. Breeding takes place during night-time. Males arrive before fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winner And Loser Effects
The winner and loser effect is an aggression phenomenon in which the winner effect is the increased probability that an animal will win future aggressive interactions after experiencing previous wins, while the loser effect is the increased probability that an animal will lose future aggressive interactions after experiencing previous losses. Overall these effects can either increase or decrease an animals aggressive behaviour, depending on what effect affects the species of concern. Animals such as ''Agkistrodon contortrix'', ''Rivulus marmoratus'', and ''Sula nebouxii'' show either both or one of these effects. The outcomes of winner and loser effects help develop and structure hierarchies in nature and is used to support the game theory model of aggression. Causation A theory underlying the causation of the winner and loser effect deals with an animals perception on its own and other members resource holding potential. Essentially if an animal perceives that it has a high r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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