Diagnosis: Fin-ray counts of D-IX,10 A-III,9 are shared by all Caribbean parrotfishes, however a mode of 14-16 pectoral-fin rays indicates Scarus. The remaining parrotfishes Sparisoma, Cryptotomus roseus, and Nicholsina usta all have 13 pectoral-fin rays, while the similar-appearing wrasse Doratonotus megalepis shares the median-fin-ray count but has only 11-12 pectoral-fin rays. There are six Caribbean Scarus species, with some slight separation by pectoral-fin-ray count: Scarus iseri and S. taeniopterus have 13-14 pectoral-fin rays (modal 14), S. vetula has 14, rarely 15, S. coeruleus usually has 15, and S. guacamaia and S. coelestinus have 16 pectoral-fin rays. Separating the larvae of those species with overlapping pectoral-fin ray counts requires DNA sequencing. Scarus iseri (often mistakenly cited as Scarus iserti) vastly outnumbers the other species at most Caribbean locations.
Description: Body relatively thin, typically long and narrow with a large eye and a terminal small mouth (some individuals are more wide-bodied and leaf-shaped and are presumably approaching transition). Pectoral fins short and pelvic fins stubs in pre-transitional larvae. Dorsal and anal-fin bases relatively long, caudal peduncle short and relatively wide. Lightly marked; an irregular row of up to 12 melanophores along or beneath the base of the anal fin extending into the caudal peduncle. There is marked variability in the line-up of this row of melanophores. The typical pattern for the first seven melanophores is the first three after the vent are deep in the body and not along the base of the anal-fin rays and the next four are located at the base of the fin rays and can be expanded and appear larger than the rest (i.e. 3+4, sometimes 4+3). The next in the row is usually well above the fin base and the then last four are in a row starting near the base of the last anal-fin ray slanting up into the caudal peduncle musculature. Many individuals are missing some of the row of melanophores, some show as few as five. There is a variable row (from none to 10, occasionally 20 or more) of tiny melanophores along the dorsal midline of the caudal peduncle (often can be slightly offset and variably paired), starting just behind the base of the last dorsal-fin ray. Melanophores occur internally around the gut near the vent and often there is an additional melanophore around the gut well above the vent along the posterior peritoneum. Series of transitional larvae show development of the eye from a narrowed vertical oval, usually tilted forward with a sometimes marked posterior-inferior extension of the iris, to large and round with a relatively small pupil at transition. Many pre-transitional larvae have a ventral indentation in the iris, sometimes with a dorsal indentation as well, and rare individuals have the narrowed eyes clearly tilted backward. Some transitional individuals develop a particularly bulbous eyeball with a tiny pupil. Transitional larvae develop a scattering of tiny melanophores on the top of the head along with a bar of iridophores slanting upward from the back of the eye and in a stripe from the eye to the pectoral fin base. On the body, large leukophores develop along the base of the dorsal and anal fins and three leukophore patches appear at the base of the upper, mid, and lower segmented caudal fin rays. The larval row of melanophores along the anal-finbase disappears. Transitional recruits develop additional melanophores densely covering the top of the braincase and a scattering on the snout and along the upper jaw and a stripe angling upward from the rear of the eye. Additional melanophores develop in two dense stripes along the body, wider below the lateral midline than above. Stripes develop later along the base of the dorsal and anal fins.
Analogues: Wider-bodied Scarus larvae can resemble larval Doratonotus megalepis, but the latter do not have the row of melanophores along the base of the anal fin. Transitional Scarus larvae lose their anal-fin base melanophores, and then the two taxa can be separated by the pattern of transitional melanophores on the head.
Ten genera of parrotfishes are recognized (Bellwood, 1994), of which Scarus is the largest, with over 50 species, and the only one present in all tropical and subtropical oceans. The general morphology is similar for most species of Scarus , and identification of the Indo-Pacific species of Scarus can be difficult for preserved specimens that have lost their distinctive life color. Meristic data are of limited value in species identification. Parrotfishes normally have IX, 10 dorsal rays and III, 9 anal rays. The number of pectoral rays of the species of Scarus vary from 13 to 16, and the count is strongly modal for each species, so it is often helpful. The usual lateral-line scale count of 17-18 + 4-6 is of no diagnostic value, but the number of predorsal scales and the number of rows of scales on the cheek are often useful characters. The gill rakers are small and variable in number within a species. Life colors remain the most important distinctive features in the classification of Scarus , but sexual dichromatism and the different color of the juvenile stages (Bellwood 1989, Bellwood & Choat 1989) can complicate species identification.
Parrotfishes have extreme variation in color with growth and with sex change (Choat & Randall 1986; Bellwood & Choat 1989), and the juvenile and initial phase color patterns are often difficult to distinguish among species. This has led to a strong focus on the more colorful males as the basis for species descriptions. In the present paper, however, the initial phase coloration is distinctive, with three prominent dark spots on the dorsal, pectoral base, and anal fins, forming the etymological basis for the naming of this new parrotfish species. The authors collected this species independently on the coral reefs of Surin and the Similan Islands of Thailand and the Mentawai Islands, Sumatra.
Scarus is a genus of parrotfishes. With 52 currently recognised extant species,[3] it is by far the largest genus in this family. The vast majority are found at reefs in the Indo-Pacific, but a small number of species are found in the warmer parts of the eastern Pacific and the western Atlantic, with a single species, Scarus hoefleri in the eastern Atlantic. Most are very colourful, and have strikingly different initial (males and females) and terminal (males only) phases. Adults of most species reach maximum lengths of between 30 and 50 cm (12–20 in), but the rainbow parrotfish (Scarus guacamaia) can grow to lengths of 1.2 m (3.9 ft).[3]
There are currently 52 recognised species in this genus:[3]
In Cesare Ripa's Renaissance iconography, the scarus fish symbolised civil "Union," i.e. the joining together of individuals into a collective body. Plutarch had written that scarus fish "swim together in shoals and ingeniously and heroically free each other when caught in a net." The scarus thus "denoted reciprocal assistance in the fight for survival."[4]
Female Scarus falcipinnis
Male Scarus globiceps
Male Scarus psittacus
Scarus zelindae in its mucus cocoon
Scarus is a genus of parrotfishes. With 52 currently recognised extant species, it is by far the largest genus in this family. The vast majority are found at reefs in the Indo-Pacific, but a small number of species are found in the warmer parts of the eastern Pacific and the western Atlantic, with a single species, Scarus hoefleri in the eastern Atlantic. Most are very colourful, and have strikingly different initial (males and females) and terminal (males only) phases. Adults of most species reach maximum lengths of between 30 and 50 cm (12–20 in), but the rainbow parrotfish (Scarus guacamaia) can grow to lengths of 1.2 m (3.9 ft).
