Green Humphead Parrotfish picture used with permission


           Most parrotfishes are protogynous hermaphrodites (R. J Hamilton et al. 2008; Encyclopedia of Aquatic World et al. 2011). This is because these fish form a group with one male and many females, which means that if the male dies the dominant female will undergo a sex change (five day change) to become the dominant male (R. J Hamilton et al. 2008; Robertson et al 1978). Unlike most parrotfishes the Bolbometopon muricatum is said to be gonochoristic or protogynous hermaphrodites which means that the sexes are separate but there is a branch that allows a secondary male to become female or become a primary male. Because of this pattern most parrotfish begin as female and undergo a sex change to become male (R. J Hamilton et al. 2008). The males that can change are called secondary males as they are bisexual for one part of their life before changing into a primary male. When the males possess hermaphroditic qualities a pre-reproductive period takes place that makes physiological changes required to become a male when the dominant male dies, or leaves the group (R. J Hamilton et al. 2008; Dive the World 2012).
          Reproduction then can occur once both sexes reach sexual maturity.  After the change the male undergoes they will continue to grow to reach sexual maturity around the age of 5-7 years. During this time females are continuing to grow to reach maturity around the age of 9-11 years (R. J Hamilton et al. 2008). This time is different because there is a high demand of males and they grow faster than females. When both male and female reach maturity spawning can occur throughout the year if conditions are stable and productive. Spawning usually occurs in the morning in reef passages (Kobayashi et al.  2011). Refer to Habitat page for more details. Courtship and pelagic spawning activities occur during the early morning and eggs are laid in shallow grooves often by aquatic plants. These plants are used to protect and camouflage the eggs from being eaten by predators. After they hatch the newly-hatched offspring often times stay in this secluded area for up to a year to grow and mature before joining the adults in the reefs (Kobayashi et al. 2011).

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