The reproductive organs of fish or male fish, including testicles and ovaries. In most species, gonads are paired organs of similar size that can be partially or completely fused. There may also be a range of secondary organs that increase reproductive adaptability.
Genital nipples are small, fleshy tubes, sperm or eggs released from behind the anus of some fish. The gender of a fish can usually be determined by its papillary shape.
In many animal species, it is expected to choose a partner based on criteria related to their own health. The direct benefits obtained by adaptive partner selection include the material resources provided by men as well as brooding and protection, which can increase the female’s current and lifetime fertility. The indirect benefit of a woman comes from her offspring’s high fitness, and the male contributes genes and parents’ investments.
A trade-off between direct and indirect benefits has been identified in several species, but a positive correlation can be made if the genetic quality of a male can also benefit the female partner directly.
If a man needs certain resources (such as territory or nest) for mating, male competition can narrow down the candidate partner’s group to competitive individuals, thereby facilitating female choice.
Female choices in successful male choices in competition within resources may be based on characteristics of the male themselves, such as size, color or behavior, and the quality of the resource. Women of certain species, especially in fish, have been shown to prefer larger males (poeciliidae; cyprinidae:; rivulidae; rivulidae; spiders.
The putative benefits of women mate with large males include protection against abuse and predation, increased fertilization and heritable dominance.
Male coloring is another potential partner choice tip. In particular, female preference for men with dense red and orange colors (Birds: Reptiles: Amphibians: Fish: Possibly related to the link between carotenoid pigmentation and individual status.
The correlation between female preferences and male courtship efforts is also widespread (e.g., wolf spiders, fish, popsicles, birds, and there is some evidence that male courtship efforts can demonstrate the quality of men to women. Sound production is an important part of many animal courtships, including insects, birds and Anururas.
Male fish can also produce sounds during courtship, and partner selection experiments have verified the effect of fish courtship sounds on female preferences.
In species where male resources either provide direct benefits for women’s fitness or serve as indicators of male quality, resource characteristics often influence female choice.
Using territorial quality as a partner choice tip, women may profit from the shelter and food provided by the territory while being in good condition with men, limiting ownership of high-quality territory to high-quality men if men compete with men.
Conversely, if the quality of male resources (such as territory or nest) is critical to female reproduction and is not related to male status, women may face a decision between choosing a high-quality male or high-quality resource.
Among the cichlids Tropheus mooriithis is the local nature of Lake Tanyne, the inherent masculine and territorial traits are reasonably used as female companion selection clues.
Therefore, female preferences can directly drive the evolution of male traits and can strengthen the selection pressure exerted by male competition on territory.
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Many populations in this genus tropheus It has obvious colors and rich geographical color differences within the species. Cichlid color patterns diversification are often associated with male-male competition and female choices, but social systems tropheusOn both male and female territories, a need for women’s competitiveness in territorial competitions has also been proposed. Sex competitions against territories may require women to match men in terms of their resource holding potential.
Indeed, most of the population tropheus It is sexually monomorphic in body shape and color patterns, both men and women use body color signals to convey social status and motivation with territorial competitors.
Sexual monomorphism is usually only associated with weaker internal selection. However, single-parent maternal breathing tropheus Women require male biased surgical sex ratios, so female fish selection can vary in male mating success.
If the female partner’s choice selects a specific characteristic of the male, and this characteristic is also associated with territorial success, then two competitions may subsequently select the same characteristic in the female and maintain sexual monomorphism.
Therefore, women’s preference for male coloring may be involved in the evolution of the obvious color patterns shown by many, many people tropheus Isodiversity of color patterns in populations and populations.
tropheus Feeding on rocky algae on the rock surfaces of shallow coastal areas. Successful mating success tropheus Men depend on the ownership of their territory, which allows them to provide feeding opportunities for their peers.
Although a lonely woman tropheus Defending one’s own feeding territory, the energy drawn from its resources obviously does not allow them to mature to lay eggs, which may be due to the lower quality of the territory or due to the requirements of territorial defense.
Perhaps due to this nutritional requirement, the mating system of this single-parent maternal mouth involves bonding up to 3 weeks before spawning.
During this time a woman prepares for egg laying on her partner’s territory while a man takes charge of the defense of the territory. After laying the eggs, the female gave up the male breathing sound.
The single parent-child relationship of brooding shows that unpaired males do not participate in reproduction. Among the population of northern Tanyne Lake (tropheus sp. Bemba’s “black”), the territory of paired men is characterized by famous rocks and large rock surface areas.
The rocky areas on male territory are related to male figures, while the female territory is smaller and the rocky areas are smaller than the male territory. Together, this shows that competition among men is provided for high-quality territory, which may require the provision of critical nutritional resources for women.
Now, let’s look at the following inbreeding process:
Inbreeding of fish or male fish
1) Depression of close relatives
The effect of inbreeding on reproductive behavior was studied in Poeciliid Fish Miscellaneous Shermosa. Mating of one generation was found to reduce reproductive performance and possible reproductive success in male offspring. Other characteristics that show intimate depression are male and female offspring viability and maturity time.
Zebrafish are exposed to chemical environmental agents, similar to those caused by human contamination, which amplifies the effects of inbred on key reproductive characteristics. In inbred naked fish, embryo viability is significantly reduced, and there is a tendency for offspring of inbred men.
The behavior of teenage salmon was compared in pairing competitions. Low inbreeding fish almost showed an aggressive pursuit of defending territory, which was moderately bred, and had a higher specific growth rate.
Significant effects of in-kin depression on juvenile survival were also found, but only in high-density competitive environments, suggesting that specific competition can amplify the harmful effects of inbredness.
2) Avoid
Inbreeding often has negative adaptive consequences (inbred depression), so species have mechanisms to avoid inbredness. Many close relative avoidance mechanisms that operate prior to mating have been described. However, the mechanism of close relative avoidance that operates after mating is little known.
In guppies, a counterfeiting mechanism of close relative avoidance occurs based on competing for male sperm to achieve fertilization. In the competition between sperm from unrelated men and sperm from all sibling men, a bias from paternity test against unrelated men was observed.
In-kin depression is thought to be mainly due to the expression of homozygous harmful recessive mutations. Hybridization between irrelevant individuals leads to beneficial masking of harmful recessive mutations in offspring.
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example
goldfish
The female fish spawn (excreted) eggs in the water are encouraged by male goldfish, which simultaneously expel sperm and fertilize eggs from the outside.
Within two or three days, the fragile female eggs hatch into larvae and rapidly develop into fried meat. Like all Ceplins, goldfish are egg layers. They usually start to reproduce after major changes in the spring. Men chase women, prompting them to release eggs by hitting and nudge them.
When the female fish produces eggs, the male goldfish approaches after fertilizing. Their eggs have adhesives and are attached to aquatic vegetation. The eggs hatch within 48 to 72 hours.
In a week or so, the fries start to take their final shape, although a year may pass a year before the mature goldfish color can be developed. Until then, they were metal brown like wild ancestors. In the first few weeks of life, fries quickly grew out of the high risk of being swallowed by adult goldfish.
carp
Members of cyprinidae are carp spawning between April and August, mainly depending on the climate and conditions they are in. The oxygen level of water, food availability, size of each fish, age, age, number of fish, water temperature and water temperature are all factors that produce carp at any time at any time.
Siamese Fighting Fish
Before spawning, male Siamese fighting fish will build foam nests of different sizes on the water. When a male is interested in a female, he will burst out g, twist his body and spread his fins. The female turns black and bends her body back and forth.
The act of laying eggs occurs in a “western hug”, where the male wraps his body around the female, and each hug releases 10-40 eggs until the female runs out of the eggs.
The male was released from his side into the water and fertilization occurred outside. During and after the spawning, the male uses his mouth to retrieve the sinking eggs and store them in a foam nest (it sometimes helps her partner when pairing the female, but more often she just swallows all the eggs she manages to capture).
Once the female releases all her eggs, she is driven out of male territory because she is likely to eat eggs due to hunger.
Female eggs are then retained in male care. He kept them in the foam nest, making sure they didn’t fall to the bottom and repaired the nest as needed. Incubation lasts for 24-36 hours, and newly hatched larvae remain in the nest for the next 2-3 days until their yolk sac is fully absorbed. After that, the frying leaves the nest and the free swimming stage begins.
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