[2] General examples of polyandry occur in fish species, such as green swordtails[1] and Trinidadian guppies.
[1] These Poeciliid species include green swordtails, Xiphophorus helleri[1] and Trinidadian guppies, Poecilia reticulata.
[3] When females mate promiscuously and copulate with multiple males, the interests of the sexes may differ, leading to sexual conflict.
These conflicts include mating and fertilization frequency, parental efforts, and power struggles between male and female dominance.
[9] Females who engage in polyandry obtain certain advantages such as shorter gestation times, larger broods, and the production of offspring with better phenotypes and abilities.
[8] Females prefer phenotypically bright colored males that are usually orange, red, yellow, or blue.
Male pregnancy is a common feature in the family Syngnathidae, which includes pipefish, seahorses, and sea dragons.
[12] Males are usually capable of combining uniparental care with defending their territories or nest, attracting females for copulation.
[12] The pipefish species, Syngnathus typhle males can only carry approximately half of the brood produced by a larger female.
[14] Kin selection occurs when individuals help their offspring to increase their inclusive fitness, which includes aid in defending their territory and being related to females.
[14] Cooperative polyandry occurs in the cichlid species, Chalinochromis brichardi and Julidochromis transcriptus from Lake Tanganyika[13] and the Neolamprologus pulcher.
Females can induce the paternity allotment of her potential mates by choosing where she deposits her eggs within her nesting site.
[17] Strong evidence for female indirect benefits has not yet been determined, suggesting one reason for convenience polyandry.
[6] These males develop long, narrow mouths and longer teeth that aid in biting female pectoral fins during mating.
[6] Some shark species, such as catsharks, Scyliorbinus carnicula, exhibit a different form of convenience polyandry.
[6] Several viviparous shark species, where females give birth to live offspring that develop internally within the mother, also engage in polyandry.
[16] In viviparous mating, a direct transfer of nutrients from mother to embryo through a yolk sac placenta occurs.
[20] Selecting specific nursery sites influence adult fitness, recruitment, and provide a protected area for live offspring to develop.
[6] Copulation requires a substantial amount of energy and females that mate with multiple males causes a negative effect on their overall fitness.
[22] One hypothesis states that females can engage in polyandry to find genetically dissimilar and therefore compatible males to produce high quality offspring.