Polydactylus approximans (Lay & Bennett, 1839)
Blue bobo
Polydactylus approximans
photo by Robertson, R.

Family:  Polynemidae (Threadfins)
Max. size:  36.8 cm TL (male/unsexed)
Environment:  demersal; brackish; marine; depth range 10 - 60 m
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).
Diagnosis:  Dorsal spines (total): 9-9; Dorsal soft rays (total): 11-13; Anal spines: 3-3; Anal soft rays: 13-15; Vertebrae: 24-24. 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).
Biology:  Found in shallow water near the coast, on sand and mud bottoms (Ref. 9332). Larvae and small juveniles (>4 cm) are pelagic and sometimes occur several hundred kilometers offshore, whereas the larger juveniles and adults prefer shallow near-shore waters like bays, sloughs or estuaries where the bottom is sandy or muddy (Ref. 28023). Omnivorous, feeds on worms, sand crabs, shrimp, clams; sometimes feeds on fish like small anchovy (Ref. 28023). Esteemed food fish where it occurs (Ref. 57343). Also Ref. 55763.
IUCN Red List Status: Least Concern (LC); Date assessed: 24 May 2007 Ref. (130435)
Threat to humans:  harmless
Country info:   
 


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