Carapus acus

Author: Brünnich, 1768

Carapus acus Brünnich, 1768

Status in World Register of Marine Species:
Accepted name: Carapus acus (Brünnich, 1768) (updated 2009-06-25)

Diagnosis: eel-like; head l/7-1/8 TL; anus anterior to pectoral fin base; pectoral fin one-half head length. Teeth in jaws small and uniform, vomerine teeth somewhat larger than jaw teeth on midline and smaller laterally. 37-39 dorsal finrays; 58 anal finrays to thirty-first vertebra; 18 precaudal vertebrae. Colour: translucent with about 15 large silver-gold iridescent spots laterally on operculum and thoracic region; silver peritoneum. Size: to 200 mm TL.

Habitat: adult typically commensal in the holothurians Holothuria tubulosa and Stichopus regalis, both occurring in shallow water. Tenuis larva probably in the same host species. Vexillifer and egg-rafts in the plankton. Commensal; may partly protrude or entirely leave host nocturnally to feed (Gustato, 1976). Food: bottom invertebrates or small fishes, and probably cannibalistic, as shown for other species of Carapus (Trott, 1970), Reproduction: July-September, site unknown.

Distribution: entire Mediterranean, common in western part; recorded from coastal waters of Italy, Spain, France, Sardinia and the Balearic Is.; may also occur in the Adriatic and Aegean Seas, but probably only rarely in the Atlantic.

Eggs, larvae ana young stages. Arnold, 1956: 264 | Padoa, 1956: 763, pl. XLIV (fig. 13, 15), pl. XLV (fig. 1-13) | Gustato, 1977: 505, fig. 1-4.
Otoliths (sagitta). ? Chaine, 1949: 186-188.