Aequidens pallidus (Heckel, 1840)
Doublespot acara
Aequidens pallidus
photo by DATZ

Family:  Cichlidae (Cichlids), subfamily: Cichlasomatinae
Max. size:  14.3 cm SL (male/unsexed)
Environment:  benthopelagic; freshwater; pH range: 6.5 - 7.5; dH range: 10
Distribution:  South America: Amazon River basin, in the middle and lower Negro River, Uatumã, Preto da Eva, and Puraquequara rivers.
Diagnosis:  This species is moderately large (to c. 14.0 cm) with triserial predorsal scale pattern, relatively long pectoral fin (36.6-44.6% of SL) and 25-26 scales in the E1 row. It is most similar to A. tubicen, both of which have an enhanced, wide light spot anterior to the caudal spot, lateral band high on side, posteriorly positioned midlateral spot, and high vertebral count (14 + 13 = 27). A. pallidus differs from A. tubicen in the colour pattern, having a supraorbital spot, (vs. none in A. tubicen) and a normal cheek spot (A. tubicen has a preopercular spot). In this species the posterior part of the lateral band is uninterrupted at all sizes (vs. divided into blotches in A. tubicen). Aequidens pallidus, though resembling A. diadema, can be distinguished from the latter by having higher E1 scale row count 25-26 (vs. 24); much narrower dark margins on dorsal flank scales; and, more posteriorly positioned midlateral spot (through E3 scales 12-15 instead of c. 10-13) (Ref. 86501).
Biology:  Collected from lotic black to clear water: in Rio Uatumá, this species was collected from marginal pools in rapids after the Balbina dam was closed and the river level dropped considerably below normal low water Ievel; Río Preto da Eva site was a relatively slow flowing small forest stream, while the Igarape Tarumázinho site was a swift flowing forest stream. Although collections indicate swamps and lakes, this species has been collected mostly in running water. Reported food items of specimens from Río Negro were chiefly fish and detritus (Ref. 86501). Inhabits rivers (Ref. 12251). Maximum length 20.0 cm TL (Ref. 40602).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (123251)
Threat to humans:  harmless
Country info:   

Entered by: Sa-a, Pascualita - 27.02.98
Modified by: Capuli, Estelita Emily - 22.02.11
Checked by: Kullander, Sven O. - 12.02.01

Source and more info: For personal, classroom, and other internal use only. Not for publication.

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