Biology

Gardiner describes four variants which occupy different habitats and depth ranges.

"i. Var. typica Ortm., 1897, Alcock, ill. p. 220.
On reefs and in lagoons down to 35 fathoms in Goifurfehendu, Male, Fadifolu, Addu, Minikoi, South Nilandu, Suvadiva, and South Male Atolls.
ii. Var. dentata (Mackay), 1838. Ortmann, loc. cit. p. 204.
On reefs at Male, Goifurfehendu and Fadifolu Atolls and in Suvadiva lagoon in 25 fathoms.
iii. Var. guttata Rlippell, 1830. Alcock, ill. p. 221.
On the reef in Goifurfehendu and in the lagoons of Mahlos, Suvadiva and North Male Atolls down to 25 fathoms.
iv. Var. muculata (Mackay), 1838. Alcock, in. p. 221.
On the reefs in Goifurfehendu, Male, Fadifolu and Minikoi Atolls, and in the lagoons at Suvadiva and South Nilandu down to 25 fathoms."