Chaetobranchus

Chaetobranchus flavescens, drawing from Castelnau Expédition dans les parties de l' Amérique du Sud centrales, de Rio de Janeiro à Lima, Lima et de au Para: exécutée par ordre du gouvernement Français pendant les années 1843 à 1847 - Paris:. P. Bertrand, 1850-1857

Chaetobranchus is a genus of cichlid from tropical South America. The scientific genus name refers to the long, fine gill rakers of the genus ( Gr. " chaetos " = bristle " branchiae " = gill ). The two species of the genus occur in the Amazon basin, in the basin of the Orinoco and the three Guiana's in slow-flowing waters.

Features

Chaetobranchus species are 21 to 25 inches long. Your body is high, laterally flattened, the head profile is pointed. Its basic color is yellowish to brownish. The fish shimmering silvery metallic. They differ in adaptations to a plankton -eating life of all other South American cichlids. Their gills Reuse rays on the first branchial arch are long, slender and are close together. In the direction of the skull and Hypobranchiale they are progressively shorter and the distance is greater. The Chaetobranchus species are the only cichlids with dentate Basibranchialen, the lowermost portions of the gill arches. Another unique feature is the Chaetobranchus for possession of tiny gills Reuse rays in the lower pharynx.

The mouth is large, the narrow rows sitting on the pines teeth are small with a single peak. The lower pharyngeal jaw is long and slender, set with a deep posterior margin, and with numerous small pointed teeth. The lips are continuous, the lower lip is attached to the rear edge of the upper lip, well above the posterior margin of premaxilla and maxilla. This lip type is characteristic of New World cichlids ( subfamily Cichlinae ). The squamation before the dorsal fin is irregular. On the bottom, on the throat there is an overlapping group that is separated from the rest of squamation. For lateral-line system has seven pores on the Vorkiemendeckel and five on the lower jaw, and other head pores. Unusually for cichlids are some rows of pore- bearing scales on the tail fin, long -fin rays between the D1 and D2 and another on the lower part of the tail fin, which is an extension of the bottom line.

System

Together with the sister genus Chaetobranchopsis forms Chaetobranchus the tribes Chaetobranchini within the New World cichlids ( Cichlinae ), which forms the sister group to the Geophagini. From Chaetobranchopsis to Chaetobranchus differs inter alia by 5-6 (usually 4) spines in the anal fin, Chaetobranchopsis has three spines.

Species

• Chaetobranchus flavescens Heckel, 1840 type species; prevalent in the Amazon and Orinoco basin and in the three Guiana, dorsal and anal fin unbeschuppt, 16 scales in a transverse row, no eye-spot on the caudal fin base, no vertical stripes on the sides of the body.
• Chaetobranchus semifasciatus Steindachner, 1875; beschuppt only in the central Amazon region between Óbidos and Tefé, dorsal and anal fin, 20 smaller scales in a transverse row, an eye spot on the caudal fin base, broad, vertical stripes on the body sides. Opposite Chaetobranchus flavescens has this kind of a small protruding jaw and narrow rows of scales on the dorsal and anal fin bases. Kullander has about the transfer to another monotypic genus considered, this step is (still ) not completed. .