Scientific Name
Polydactylus approximans

Common Name
Blue bobo

Biology
Dorsal spines (total): 9; Dorsal soft rays (total): 11-13; Anal spines: 3; Anal soft rays: 13 - 15; Vertebrae: 24. Body grayish, no stripes or spots. Lip on lower jaw well developed. Dentary teeth restricted to dorsal surface. Maxilla not covered with scales. Pectoral filaments 6; longest not reaching beyond level of posterior end of anal fin base. Lateral line bifurcated on caudal fin membranes, extending to posterior margins of upper and lower caudal fin lobes. Swim bladder present (Ref. 45049).

Classification

Classified By

Lay & Bennett, 1839

Class

Ray-finned fishes (Actinopterygii)

Order

Perch-like fish (Perciformes)

Family

Threadfins (Polynemidae)

Distribution

Region

Eastern Pacific

Distribution

Eastern Pacific: Monterey Bay, California, USA to Callao, Peru. One record from the Galapagos Islands. Rare north of Baja California, Mexico (Ref. 2850). Record from Chile (Ref. 9068) needs to be verified (Ref. 57343).

Range

37°N - 12°S, 122°W - 77°W

Environment

Climate

Subtropical

Water Temperature From

Unknown °C

Water Temperature To

Unknown °C

Depth From - meters

Unknown m

Depth To - meters

30 m

Zone

demersal

Environment

Marine; demersal; depth range ? - 30 m (Ref. 45049)

Trophic Level

3.7 s.e. 0.62 Based on diet studies.

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

36.0 cm

Common Length

20.0 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

Fisheries: commercial

Vulnerability

Low vulnerability (24 of 100)

Resilience

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

Threat To Humans

Harmless

IUCN Red List Status

Least Concern (LC)