Helcogramma billi Hansen 1986

Diagnosis: Dorsal fin III + XIII+ 10-11, second fin twice height of first in males (Comoro Is.); anal fin I + 19-20; pectoral rays 16 (2+7+7); pelvic fin I, 2, spine short and hidden, segmented rays simple, partially united by membrane. Vertebrae 10 + 25-26. LL total lateral scales 38-39, pored series 19-25 (121) scales, terminates at caudal fin base; nape with scales, bases of caudal and anterior of anal fin scaleless. Mandibular pores 2-3+1+2-3. Head length 3.4 in SL; eye 2.8; maxilla 2.2 in HL. Body with 5 H-shaped bars; dorsal, anal and caudal fins pigmented with spots or stripes. Live color not known but in alcohol females and juveniles are paler than males (Ref. 75031).

Dorsal spines (total): 16 - 17; Dorsal soft rays (total): 9 - 11; Analspines: 1; Analsoft rays: 17 - 20; Vertebrae: 35 - 36

Lives on rock surfaces and under ledges; common at depths less than 10 m (Ref. 6211).

Adults live on rock surfaces and under ledges; common at depths less than 10 m (Ref. 6211). Eggs are hemispherical and covered with numerous sticky threads that anchor them in the algae on the nesting sites (Ref. 240). Larvae are planktonic which occur primarily in shallow, nearshore waters (Ref. 94114).

Helcogramma billi is a species of triplefin blenny in the genus Helcogramma. It was described by Patricia E. Hadley Hansen in 1986, and the specific name honours the American ichthyologist Bill Smith-Vaniz, who collected the types Hadley Hansen examined when describing the species. This species is common on rock surfaces and beneath ledges in waters down to 10 metres (33 ft) in depth around the coasts of Sri Lanka.