Bidirectional Sex Change PDF

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Summary

Bidirectional hermaphrodites have the capacity for sex change in either direction, potentially repeatedly during their lifetime.
Field evidence for bidirectional hermaphroditism is limited to 10 species in 5 families [Manabe et al., 2013; Kuwamura et al., 2015], and most reports are for speci...

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Bidirectional Sex Change Bidirectional hermaphrodites have the capacity for sex change in either direction, potentially repeatedly during their lifetime. Field evidence for bidirectional hermaphroditism is limited to 10 species in 5 families [Manabe et al., 2013; Kuwamura et al., 2015], and most reports are for species formerly thought to be protogynous. For example, in some socially polygamous and primarily protogynous species where social structure is highly unstable, sexchanged males may revert back to female should they find themselves competing with a larger male (e.g., Okinawa pygmy goby, Trimma okinawae, Manabe et al. [2007]; cleaner wrasse, Labroides dimidiatus, Kuwamura et al. [2011]). Natural bidirectional sex change has not been reported for any otherwise protandrous species. True serial sex change is characteristic of monogamous coral-dwelling gobies (e.g., Gobiodon and Paragobiodon). Sex change in these fish is not well explained by the SAM and is thought to provide reproductive assurance in the face of niche specialisation and a sessile lifestyle [Nakashima et al., 1995; Munday et al., 1998]. Coral gobies experience limited mating opportunities and a high risk of moving between spatially isolated coral colonies. ability to change sex repeatedly in either direction allows any 2 fish to form a heterosexual breeding pair, thus reducing travelling distance and predation risk when finding a partner as well as time between breeding events [Munday, 2002; Munday et al., 2010]...