Scientific Name
Stegastes insularis

Common Name
Island gregory

Biology
Dorsal spines (total): 12; Dorsal soft rays (total): 15-17; Anal spines: 2; Anal soft rays: 11 - 13. Scales of head and body finely ctenoid, few cycloid may be present on ventral of head and on snout. Pale blue-gray to charcoal in color with dusky gray scale margins, appearing as series of narrow transverse bands. The posteriormost part of body, caudal peduncle, caudal fin and posterior part of dorsal fin are bright yellow; suborbital bluish and lavender. An elongate black patch with narrow blue margin is between 1st and 4th dorsal spines. The pectoral fins are translucent with a suffusion of yellow. A small black spot is at the base of the uppermost rays of the pectoral fin.

Classification

Classified By

Allen & Emery, 1985

Class

Ray-finned fishes (Actinopterygii)

Order

Perch-like fish (Perciformes)

Family

Damselfishes (Pomacentridae)

Distribution

Region

Eastern Indian Ocean

Distribution

Eastern Indian Ocean: Christmas Island Northwest Pacific: Marcus Island (Minami Tori Shima). These isolated populations are probably relicts of a once widespread species.

Range

32°N - 15°S

Environment

Climate

Tropical

Water Temperature From

Unknown °C

Water Temperature To

Unknown °C

Depth From - meters

1 m

Depth To - meters

10 m

Zone

reef-associated

Environment

Marine; reef-associated; non-migratory; depth range 1 - 10 m (Ref. 9710), usually 1 - 3 m (Ref. 9710)

Trophic Level

2 s.e. 0.00 Based on food items.

Occurs in Marine / Salt water

True

Occurs in Brackish water

False

Occurs in Fresh Water

False

Occurs on Reefs

True

Is kept in Aquariums

False

Physical Size and Genetics

Maximum Length

11.0 cm

Common Length

Unknown cm

Phylogenetic Diversity Index

PD50 = 0.5000 many relatives (e.g. carps) 0.5 - 2.0 few relatives (e.g. lungfishes)

Human Uses and Population

Human Uses

Unknown

Vulnerability

Low vulnerability (23 of 100)

Resilience

High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.)

Threat To Humans

Harmless

IUCN Red List Status

Not Evaluated