Opisthopterus effulgens (Regan, 1903)
Vaqueira longfin herring
photo by FAO

Family:  Pristigasteridae (Pristigasterids)
Max. size:  20.5 cm SL (male/unsexed)
Environment:  pelagic-neritic; freshwater; brackish; marine
Distribution:  Eastern Pacific: known only from the Río Vaqueira, northwest Ecuador.
Diagnosis:  Dorsal spines (total): 0-0; Anal spines: 0-0; Anal soft rays: 50. Belly with about 29 scutes. Lower jaw projecting, mouth pointing obliquely upward; no hypo-maxilla. Pectoral fin a little longer than head; dorsal fin origin nearer to caudal fin base than to vertical from pectoral fin base by about 2 eye diameters (or behind midpoint of body by about 3 eye diameters); anal fin long, its origin much nearer to snout tip than to caudal fin base.
Biology:  Either living in rivers or entering rivers from the sea (Ref. 9336).
IUCN Red List Status: Data deficient (DD); Date assessed: 29 June 2018 Ref. (130435)
Threat to humans:  harmless

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