One species, two fish, and for a long time the literature carried them as separate species.
Parrotfish live in two color phases. Young fish and most females wear the initial phase: in this species yellowish with four or five broad blue-green bars, unremarkable and easy to overlook. A few become terminal males, and a terminal male of this species is blue-green with salmon-pink edges to every scale and a blue chin, half a meter or more, patrolling a territory. Nothing about the two suggests one animal.
The switch is not only color. A female changing into a terminal male rebuilds her gonads, grows, changes her behavior from grazing in a loose group to holding ground and courting, and does the whole thing in weeks.
What triggers it is social. Remove the terminal male from a group and the largest initial-phase fish begins the change within days, which means the population carries a standing reserve of replacements and the reef never runs short of them.
This one tolerates murky water and river-influenced coast better than most parrotfish, so it turns up on ground where the rest of the family thins out.
The genus.Scarus Forsskål 1775 - skaros (ancient Greek name of Sparisoma cretense). ETYFish
The species.Scarus ghobban Fabricius 1775 - Arabic name for this fish. ETYFish
How to recognise it
initial phase yellowish with four or five broad blue-green bars
terminal males blue-green with salmon-pink scale edges and a blue chin
This species is caught in large number as bycatch from Malaysia and Indonesia (P. Rahardjo pers comm. 2009) and is common in markets but is not specifically targeted. However, these are not considered to affect the overall status of its population.
Parrotfishes show varying degrees of habitat preference and utilization of coral reef habitats, with some species spending the majority of their life stages on coral reefs, while others primarily utilize seagrass beds, mangroves, algal beds, and /or rocky reefs. Although the majority of the parrotfishes occur in mixed habitat (primarily inhabiting seagrass beds, mangroves, and rocky reefs) approximately 78% of these mixed habitat species are experiencing greater than 30% loss of coral reef area and habitat quality across their distributions. Of those species that occur exclusively in coral reef habitat, more than 80% are experiencing a greater than 30% of coral reef loss and degradation across their distributions. However, more research is needed to understand the long-term effects of habitat loss and degradation on these species populations. Widespread coral reef loss and declining habitat conditions are particularly worrying for species that depend on live coral reefs for food and shelter especially as studies have shown that protection of pristine habitats facilitate the persistence of adult populations in species that have spatially separated adult and juvenile habitats. Furthermore, coral reef loss and declining habitat conditions are particularly worrying for some corallivorous excavating parrotfishes that play major roles in reef dynamics and sedimentation (Comeros-Raynal et al. 2012).
Threat classification from the IUCN Red List.
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