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Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. [1] It is observed in reptiles and teleost fish, with some reports of it occurring in species of shrimp.
Here, sex change is age-dependent. For example, the California sheephead stays a female for four to six years before changing sex [35] since all California sheephead are born female. [38] A terminal-phase male bluehead wrasse. Bluehead wrasses begin life as males or females, but females can change sex and function as males. Young females and ...
A study by Clutton-Brock (1984) on red deer (Cervus elaphus), a polygynous species, examined the effects of dominance rank and maternal quality on female breeding success and sex ratios of offspring. Based on the Trivers-Willard model, Clutton-Brock hypothesized that the sex ratio of mammalian offspring may change according to maternal ...
Some chromosomal sex determination systems in animals. A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. [1] Most organisms that create their offspring using sexual reproduction have two common sexes and a few less common intersex variations.
It is often seen that a fish will change its sex when there is a lack of a dominant male within the social hierarchy. The females that change sex are often those who attain and preserve an initial size advantage early in life. In either case, females which change sex to males are larger and often prove to be a good example of dimorphism.
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors, including Komodo dragons.
Example: Lythrypnus dalli (family Gobiidae) are a group of coral reef fish in which bidirectional sex change occurs. Once a social hierarchy is established, a fish changes sex according to its social status, regardless of the initial sex, based on a simple principle: if the fish expresses subordinate behavior then it changes its sex to female ...
Mules and hinnies are examples of reciprocal hybrids. Kunga, a cross between a donkey and a Syrian wild ass. Zebroids. Zeedonk or zonkey, a zebra/donkey cross. Zorse, a zebra/horse cross; Zony or zetland, a zebra/pony cross ("zony" is a generic term; "zetland" is specifically a hybrid of the Shetland pony breed with a zebra) Superfamily ...