Abstract
ABSTRACT A new species of Boehlkea is described from rio Japurá, Amazon basin. The new species differs from B. fredcochui by the presence of a vertically elongate humeral spot (vs. absence), complete lateral line (vs. incomplete), four rows of scales below lateral line (vs. three), and lower number of branched anal-fin rays (17-21 vs. 22-25), and from B. orcesi by the higher number of maxillary teeth (13-14 vs. 5-12), greater head length (27.9-29.9% vs. 24.3-27.5% of SL), and by the color pattern (basal half of dorsal-fin, distal portion of pelvic-fin, lower caudal-fin lobe and anal-fin with black chromatophores vs. absence of black chromatophores in the fins).
Highlights
The genus Boehlkea was proposed by Géry (1966) and considered to be similar to Hemibrycon Günther, 1864 but differing by its smaller size and by the regression of the lateral line and scales on caudal-fin base
Since no specializations related to insemination, development of glands along fins, or modifications on teeth and jaw related to a ventral mouth, which are features found in the majority genera of Clade A, Malabarba, Weitzman (2003) considered Boehlkea and Hemibrycon as the most basal genera in that clade
Among the Stevardiinae only Boehlkea and Hemibrycon share the presence of an edentulous portion of maxilla smaller than the toothed portion, associated with the largest number of teeth in the maxilla (Bertaco, Malabarba, 2010; Mirande, 2010)
Summary
The genus Boehlkea was proposed by Géry (1966) and considered to be similar to Hemibrycon Günther, 1864 but differing by its smaller size (about 40 mm SL) and by the regression of the lateral line and scales on caudal-fin base. Mirande (2010) did not analyze specimens of Boehlkea in his phylogenetic matrix of Characidae, he pointed out that the genus can be related to Hemibrycon but differing from it by the presence of scales on caudal-fin base. Based mainly on this character, Bertaco, Malabarba (2010) transferred Hemibrycon orcesi Böhlke, 1958 to Boehlkea. In a comparative study of the spermiogenesis and sperm ultrastructure of some stevardiine genera including Boehlkea, Baicere-Silva et al (2011) concluded that the stevardiines share homologous sperm characteristics, which was considered as an additional evidence supporting the monophyly of the subfamily
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
