Fishes · Bony fishes · Parrotfishes

Blue-barred Parrotfish

Scarus ghobban Forsskål, 1775

syn. Callyodon apridentatus, Callyodon dussumieri, Callyodon fuscocuneus, Callyodon ghobban, Callyodon guttatus, Callyodon speigleri +19 more

30 - 75 cm1-90 mLeast Concern

983

The Scarus ghobban, known by a variety of names including the blue-barred undefined and cream undefined, is a fascinating species of marine fish belonging to the Scaridae family. This fish can be found throughout the Indo-Pacific region, including East Africa, 🇮🇩 Indonesia, the Galápagos Islands, 🇯🇵 Japan, 🇦🇺 Australia, and extending east to 🇵🇫 French Polynesia. A recent addition to these numerous locales is the Mediterranean Sea, where the species was first recorded off the coast of 🇮🇱 Israel in 2001. It appears to be slowly expanding northward in Levantine waters, although it remains somewhat rare in this new environment.

The blue-barred undefined is an adaptable species, typically found at depths ranging from 1 to 90 meters. It flourishes in diverse habitats such as sandy bottoms, seagrass areas, marginal reefs, and even deeper waters. The environment it inhabits plays a key role in its development and behaviors.

This fish is quite striking in appearance, ranging in color from blue-green to green. It often features a central stripe that is pink on its dorsal and anal fins, while its underside can be pinkish or yellowish. Additional distinguishing features include blue markings near the pectoral fin area.

Growing quickly, Scarus ghobban can reach a maximum length of 75 cm, though its more common size is about 30 cm. With a lifespan that can stretch up to 13 years, this species tends to move in small schools and exhibits unique feeding behaviors. It has the remarkable ability to rotate its mandible bone rapidly, an action that aids in scraping and facilitates the hydrological movement of fine sediments in its habitat.

Reproduction in Scarus ghobban is an efficient process. Females release eggs into the water current, which hatch approximately 25 hours after fertilization. The young mature quickly, reducing their dependency on parental care and allowing them to thrive independently soon after birth.

While the blue-barred undefined is often caught by fishermen, both directly and as bycatch, it is not specifically targeted in fishing operations. Its dependency on coral reefs does pose potential threats due to ongoing degradation of these critical ecosystems. However, as of now, the species does not face immediate threats to its population.

As with other reef fish possessing a pelagic larval stage, Scarus ghobban exhibits high genetic diversity due to the regional currents that aid in gene flow. This genetic diversity is key to the resilience and adaptability of the species across its widespread range. For those interested in visual documentation, photos of the Scarus ghobban are available through various marine life collections, offering a closer look at this remarkable fish.

Why it's threatened

Biological resource use

Intentional use: (subsistence/small scale) [harvest] · Unintentional effects: (subsistence/small scale) [harvest]

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.