Polydactylus approximans
Blue Bobo
Collection Details
Specimens
Photos
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Records
Taxonomic Hierarchy
Actinopterygii (Ray-finned Fishes)
Perciformes (Perciformes, Also Called the Acanthopteri)
Polynemidae (Threadfins)
Polydactylus
Polydactylus approximans (Blue Bobo)
Description
This species account was compiled from
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Characters
Body shape: fusiform / normal. 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).
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).
Habitat Associations
Brackish, marine. demersal. depth range 10-60 m. Found in: estuaries.
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.
Max length: 36.8 cm TL; common length: 20.0 cm TL.
IUCN Red List Status: Least Concern (LC), assessed 2007-05-24. Resilience: High (Preliminary K or Fecundity.).
Commercial or Environmental Importance
Fisheries: commercial.
References
Schneider, M. (1995) Polynemidae. Barbudos. p. 1386-1387. In W. Fischer, F. Krupp, W. Schneider, C. Sommer, K.E. Carpenter and V. Niem (eds.) Guia FAO para Identification de Especies para lo Fines de la Pesca. Pacifico Centro-Oriental. 3 Vols. FAO, Rome.
González, G.D. and L.A. Soto (1988) Hábitos alimentícios de peces depredadores del sistema lagunar Huizache-Caimanero, Sinaloa, México. Inst. Cienc. del Mary Limnol. Univ. Nal. Autón. México 15(1)97-124.
Motomura, H., S. Kimura and Y. Iwatsuki (2002) Revision of the threadfin genus Polydactylus (Perciformes, Polynemidae) from the eastern Pacific Ocean. Ichthyol. Res. 49(4):358-366.
Motomura, H. (2004) Threadfins of the world (Family Polynemidae). An annotated and illustrated catalogue of polynemid species known to date. FAO Spec. Cat. Fish. Purp. Rome: FAO. 3:117 p.
Nieto-Navarro, J.T., M. Zetina-Rejón and F. Arreguín-Sánchez (2010) Length-weight relationship of demersal fish from the eastern coast of the mouth of the gulf of California. J. Fish. Aquat. Sci. 5(6):494-502.
Bautista-Romero, J.J., S.S. González-Peláez, L. Campos-Dávila and D.B. Lluch-Cota (2012) Length-weight relationship of wild fish captured at the mouth of Río Verde, Oaxaca, Mexico and connected lagoons (Miniyua, El Espejo, Chacahua and Pastoría). J. Appl. Ichthyol. 28:269-271. DOI: 10.1111/j.1439-0426.2011.01914.x
Comments On Polydactylus approximans