Hemibrycon divisorensis Bertaco, Malabarba, Hidalgo & Ortega, 2007

Family:  Characidae (Characins; tetras), subfamily: Stevardiinae
Max. size:  6.84 cm SL (male/unsexed); 8.16 cm SL (female)
Environment:  pelagic; freshwater
Distribution:  South America: Río Ucayali drainage in Peru.
Diagnosis:  Dorsal soft rays (total): 8-8; Anal soft rays: 25-28; Vertebrae: 38-39. This species is distinguished from its congeners by the following characters: a wide black asymmetrical spot covering base of caudal-fin rays, extending along entire length of caudal-fin rays 9 to 12-13 (except H. surinamensis); a black band in the lower half of the caudal peduncle from the region above the last anal-fin rays to the caudal-fin base; 4-5 scale rows below lateral line (vs. 5-9) except from H. mikrostiktos and H. surinamensis (Ref. 75799); differs from H. mikrostiktos by the number of branched anal-fin rays (24-30 vs. 18-21), and from H. surinamensis by the number of scale sheath along anal-fin base (17-22 vs. 12-17), and by the number of cusps in the inner row of the premaxilla teeth (5-7 vs. 4-5) (Ref. 85819).
Biology:  Type specimens were collected at the tributaries of río Tapiche which are about 2-3 m wide with crystalline water, 0.3-0.5 m deep, medium water current, sandy substrate, and with moderate amount of riparian vegetation. This species has a typical aquasperm with a spherical to slightly ovoid nucleus , suggesting that the species is non-inseminating. It was not possible to verify the presence of spermatozoa in the ovaries due to the lack of mature females. Mature males possess bony hooks on rays of all fins, except the caudal fin; the presence of which may represent a secondary sexual character (Ref. 75799).
IUCN Red List Status: Data deficient (DD); Date assessed: 23 April 2014 Ref. (130435)
Threat to humans:  harmless


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 Not for publication.