| Ecological Descriptors
|Co, R, Man
||70 (max 120)
||Det, Veg (Spo)
Parrotfish owe their name to the shape of their mouth. Instead of teeth they have two beak-like plates, like parrots. They have even rows of large, noticeable scales on their bodies. The development of parrotfishes is complex and accompanied by a series of changes in color (polychromatism). Individuals usually mature as females (Initial Phase), with some later changing to the male sex (Terminal Phase). Large robust scales are prominent.
All: Greenish beak. As it ages the head becoming blunter and tail lengthens.
Terminal phase: Orange-brown head (extent varies) and bright green rear body.
Initial phase: Centre of scales are various shades of green. Squared tail.
The largest parrotfish in Antigua reaching a maximum size of 1.2 m and a maximum age of 16 years. Usually associated with shallow waters (to maximum 25m [80ft])and in reefs with extensive sheltered lagoonal/backreef areas. This species recruits (i.e. young individuals initially settle after larval stage) primarily to mangroves. Scarus guacamaia is classified as a detritivore, with detritus/bacterial complexes and meiofauna as the primary food items. It also feeds on sponges and adults on benthic algae and feeds more similarly to Sparisoma spp. particularly Sparisoma viride, than to other Scarus spp.
The teeth are clustered together, forming a tough mouthpiece and also possess a pharyngeal apparatus, where teeth are seen in rows, found in the throat and specialised to mascerate food.
Adults will often feed in very shallow water.
Adults on reefs often have a home cave to which they retire at night or when danger threatens; makes use of the sun as an aid to locating the cave.
It is a protogynous hermaphrodite.Oviparous, distinct pairing during breeding. They live in a harem group, whereby one single terminal male is dominant in a group of females. This dominant male mates with the females in the group, and deters other male
competition. The species is diandric, meaning that the population includes primary and secondary males. A primary male was born that sex. However, a secondary male is a fish born female, that transforms into a male. This transformation of a female fish to a male fish occurs upon the death of a Terminal Phase male. His death signals the largest Initial Phase female to undergo morphological and behavioural changes, transforming into a male. “Sneak spawning / Streaking” may also occur, where Initial Phase males disguise themselves as a female in an attempt to enter the harem. At peak spawning, they release a cloud of gametes in an attempt to overwhelm the fertilisation by the Terminal Phase males. They are adapted for this process, as they have larger testes than the Terminal Phase male, therefore producing more gametes than the latter. This increases their chance of fertilising the female.
Rainbow Parrotfish TP
Rainbow Parrotfish IP
(C) Richard Eaker
(C) Van Tassell & Robertson
(C) Ross Robertson
Rainbow Parrotfish IP
Rainbow Parrotfish juvenile