Hermaphrodite
Guides
Amphibalanus amphitrite
striped barnacle, purple acorn barnacle, Amphitrite's rock barnacle
Amphibalanus amphitrite is a medium-sized acorn barnacle with distinctive purple or brown vertical stripes. It is a globally distributed marine species native to warm and temperate waters, now recognized as a significant biofouling organism. The species has become a model organism for larval settlement research due to its invasive potential, worldwide distribution, and ease of laboratory culture. Its genome has been sequenced, and extensive neurobiological studies have examined the settlement behavior of its cyprid larvae.
Anilocra
Fish Lice
Anilocra is a genus of marine isopods in the family Cymothoidae, commonly known as fish lice. Members are obligate external parasites of teleost fishes, attaching to host skin and feeding on blood. The genus exhibits sequential hermaphroditism, with individuals beginning life as males and transitioning to females as they grow. Parasitism by Anilocra species has been documented to reduce host growth rates, fecundity, and survival.
Coronula diadema
whale barnacle, humpback whale barnacle
Coronula diadema is a species of whale barnacle that lives exclusively on cetacean hosts, primarily humpback whales (Megaptera novaeangliae). First described by Carl Linnaeus in 1767, this barnacle attaches to whale skin using specialized coring structures and filter-feeds on plankton. The species exhibits simultaneous hermaphroditism and forms mating groups of up to nine individuals. Its crown-like appearance gives rise to both its scientific and common names.
Icerya
Cushion Scale Insects
Icerya is a genus of scale insects in the family Monophlebidae, notable for containing some of the few hermaphroditic insects known to science. The genus includes approximately 50 described species distributed worldwide, with several species being significant agricultural pests. The most economically important species is Icerya purchasi (cottony cushion scale), native to Australia but now cosmopolitan in distribution, which has caused severe damage to citrus crops globally. Several Icerya species exhibit androdioecy—a rare mating system where hermaphrodites and males coexist—with hermaphrodites possessing ovotestes and reproducing primarily through self-fertilization. This reproductive strategy, combined with the sessile nature of adult females, contributes to their invasive potential. The genus is named after physician-naturalist Dr. Edmond Icery of British Mauritius.
Lepas anserifera
Goose Barnacle
Lepas anserifera is a pedunculate barnacle that attaches to floating substrates including driftwood, ships' hulls, and marine debris. It possesses a capitulum of six white calcareous plates supported by an orange, flexible stalk. The species exhibits rapid growth and early maturation, with individuals reaching reproductive size within approximately two weeks under favorable conditions. As a hermaphroditic filter feeder, it plays a role in marine neustonic communities and has a cosmopolitan distribution in temperate and tropical seas.
Lysmata
cleaner shrimp, peppermint shrimp
Lysmata is a genus of marine caridean shrimp distinguished by its unique sexual system of protandric simultaneous hermaphroditism. The genus includes two main ecological groups: cleaner shrimp that live in pairs and remove parasites from fish, and peppermint shrimp that often live in aggregations and consume pest anemones. All studied species begin life as males before maturing into functional simultaneous hermaphrodites capable of both producing and fertilizing eggs. Members of this genus are heavily targeted by the ornamental aquarium trade, with some species commanding high prices.
cleaner-shrimppeppermint-shrimpprotandric-simultaneous-hermaphroditismornamental-aquarium-tradecoral-reefmutualismAiptasia-controlhermaphroditeeuhermaphroditemale-phasecaridean-shrimpLysmatidaeHippolytidaetropical-marinetemperate-marinerock-reefsponge-habitatintertidalpair-bondingaggregationsectoparasite-removalfish-cleaningaquacultureconservationfisheries-managementmisidentificationcryptic-speciesgenetic-homogeneityoutcrossingreciprocal-fertilizationegg-incubationmoltingocean-acidificationwarmingbehavioral-ecologyreproductive-ecologyPanamaGulf-of-MexicoLakshadweepSouthern-CaliforniaArabian-SeaCaribbeanIndian-OceanLysmata-amboinensisLysmata-debeliusLysmata-boggessiLysmata-wurdemanniLysmata-bahiaLysmata-intermediaLysmata-californicaLysmata-hochiStenopus-hispidus