Scientific Name
Bothragonus swanii

Common Name
Rockhead

Biology
Dorsal spines (total): 2 - 5; Dorsal soft rays (total): 4-5; Anal spines: 0; Anal soft rays: 4 - 5; Vertebrae: 32. Dorsal fins small; caudal fin rounded; pectoral fins large, supported well out from sides of body; pelvic fins very narrow and rays appear fused (Ref. 6885). Color very variable, depending on background; brown with dark bars, orange with bluish bars, or scarlet with brown bars (Ref. 6885).

Classification

Classified By

Steindachner, 1876

Class

Ray-finned fishes (Actinopterygii)

Order

Scorpionfishes and Flatheads (Scorpaeniformes)

Family

Poachers (Agonidae)

Distribution

Region

Eastern Pacific

Distribution

Eastern Pacific: Kodiak Island, Alaska to Carmel Bay, Monterey County, California, USA (southernmost range confirmed by J.R. Wolfe, pers. comm. 09/02).

Range

60°N - 34°N

Environment

Climate

Temperate

Water Temperature From

Unknown °C

Water Temperature To

Unknown °C

Depth From - meters

0 m

Depth To - meters

18 m

Zone

demersal

Environment

Marine; demersal; depth range 0 - 18 m (Ref. 2850)

Trophic Level

3.55 s.e. 0.59 Based on food items.

Occurs in Marine / Salt water

True

Occurs in Brackish water

False

Occurs in Fresh Water

False

Occurs on Reefs

False

Is kept in Aquariums

False

Physical Size and Genetics

Maximum Length

8.9 cm

Common Length

Unknown cm

Phylogenetic Diversity Index

PD50 = 0.7500 many relatives (e.g. carps) 0.5 - 2.0 few relatives (e.g. lungfishes)

Human Uses and Population

Human Uses

Unknown

Vulnerability

Low vulnerability (20 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