Pseudanos trimaculatus (Kner, 1858)
Threespot headstander
Pseudanos trimaculatus
photo by Mikolji, I.

Family:  Anostomidae (Headstanders)
Max. size:  18.8 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  South America: Brazil, Guyana, Peru (Ref. 36801), Ecuador (Ref. 91907) and Argentina (Ref. 9086). Recorded from Amazon River basin (Ref. 36801); Rio Guaporé in Brazil, Essequibo and Rupununi Rivers in Guyana (Ref. 91907).
Diagnosis:  Anal soft rays: 11-12. Can be diagnosed by having the following characters: dark transversal bars on dorsum present; dark spots absent on the center of each body scale in some specimens; usually two, sometimes three or four midlateral dark blotches on body; angle of the dorsal and ventralmost radii of body scales between 110° and 180°; and cranial fontanel partially closed (Ref. 91907).
Biology:  Adults are found in schools of 10-50 specimens in deeper water. They feed on plants (Ref. 13371). Distinct pairs breed on densely grown weedy places (Ref. 205).
IUCN Red List Status: Least Concern (LC); Date assessed: 26 June 2020 Ref. (130435)
Threat to humans:  harmless


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