Holocentrus adscensionis

Holocentrus adscensionis
Squirrelfish – Holocentrus adscensionis
FamilyScientific NameAuthorYearCommon Name
HolocentridaeHolocentrus adscensionis(Osbeck)1765Squirrelfish

All Holocentrus — Preopercle with a sharp angle and a single strong spine much longer than broad. 11 spines in anterior portion of dorsal fin, none in posterior portion. 7-10 segmented (soft) rays in anal fin. Upper lobe of caudal fin notably longer than lower lobe. Anterior segmented (soft) dorsal-fin rays elongate. Gill rakers on lower limb of first gill arch 15-18 (including rudiments and the raker at the angle of arch). White chevron band on body below posterior spinous dorsal fin.

Holocentrus adscensionis

Unique Characters: Upper jaw longer, extending beyond center of eye (13.6-15.8% standard length). Pored lateral-line scales 45-51, usually 47-49. Postorbital length usually greater than length from orbit to tip of spine at angle of preopercle. Dorsal fin lacking white spots behind spine tips, usually yellowish anteriorly.

Similar Species: Longspined Squirrelfish Holocentrus rufus. Upper jaw short, extending posteriorly at most to center of pupil (11.4-13.4% standard length). Pored lateral-line scales 50-57, usually 51-54. Postorbital length (to tip of opercular spine) usually less than length from rear of orbit to tip of spine at angle of preopercle. Dorsal fin with a distinct white spot behind the tip of each spine.

Holocentrus rufus
Longspine Squirrelfish – Holocentrus rufus
Photo Credit: G.H. Burgess