Danionella

Danionella is a genus of very small carp fish that is found in Myanmar and the Jorai River, a tributary of the Brahmaputra in the north of the Indian state of West Bengal, near the border with Assam.

Features

Danionella species are only 11 to 17 mm long and thus belong to the smallest carp fish and the smallest fish at all. Of all the other carp fishing they differ by the small number of fin rays in the pectoral fins, the pelvic fins and the tail fin ( 7-9/9-7 ). They also have a characteristic large cartilage between the mandible and maxilla ( absent in Danionella dracula ) and a cartilage, the fourth branchial arch with the fifth Ceratobranchiale (lower " pharyngeal jaws " ) links. Both cartilage occur with any other carp fish species. Most of the rest of carp fishing is Danionella distinguished by the single row of four tricuspid pharyngeal teeth on the Pharyngealia. Scales and barbels missing, a lateral line is not visible. The hull is round in cross section. The number of vertebrae is 32 to 37, the anterior and posterior chamber of the swim bladder are far apart, while the two chambers with all other cyprinids are close together or the front part of the rear chamber directly adjacent to the anterior chamber. The intestine is simple and straight.

The dorsal fin is located on the rear half of the body and is supported by two simple and six branched fin rays. With the large anal fin, which is located approximately at the center of the body, there are two simple and 11-14 branched fin rays. The caudal fin is slightly forked. Your simple main fin rays have the same diameter as the branched. The innermost fin rays of chest and pelvic fins are large and fully developed ( poorly developed in Rasbora ).

Species

So far, four species have been described:

• Danionella dracula Britz, Conway & Rüber, 2009
• Danionella mirifica Britz, 2003
• Danionella priapus Britz, 2009
• Danionella translucida Roberts, 1986 ( type species )