Senegalese gnus (lat.Torpedo mackayana) – a kind of stingrays of the genus gnusov family of gnusovy detachment of electric stingrays. They are cartilaginous fish, leading a bottom lifestyle, with large, flattened pectoral and pelvic fins forming a disc, a short and thick tail, two dorsal fins and a well-developed caudal fin. Like other members of their family, they are capable of generating electric current. They live in the central-eastern and southeastern parts of the Atlantic Ocean at a depth of 50 m. The maximum recorded length is 50 cm. They reproduce by egg production. Not of interest for commercial fishing.

Taxonomy

The new species was first described in 1919. The holotype is a 34 cm long specimen caught off the coast of Senegal (14 ° 30 _ N 17 ° 00 _ W). The species is named after one of the initiators of the research expedition to the Netherlands Antilles, during which it was found.

Area

Senegalese gnus live in the eastern Atlantic Ocean off the coast of West Africa from Senegal to Angola. They are found off the coast of Benin, Cameroon, C_te d’Ivoire, Equatorial Guinea, Gabon, Ghana, Guinea, Guinea-Bissau, Liberia, Nigeria, Sao Tome and Principe, Sierra Leone and Togo. These rays are found in the coastal zone at a depth of 50 m. They prefer to stay on a sandy or muddy bottom near river estuaries.

Description

The pectoral fins of these rays form an almost disc. On both sides of the head, electric paired organs in the form of kidneys are visible through the skin. Behind the small eyes, there are large squiggles. Five pairs of branchial slits are located on the underside of the disc.

The tail is short and thick, ending in a small triangular caudal fin. There are two dorsal fins, shifted towards the tail. The maximum recorded length is 50 cm.

Biology

Like other members of their squad, Senegalese gnus are capable of generating electricity. They reproduce by egg production. Males and females reach sexual maturity at 31.5 and 35 cm, respectively. Based on the data on the size of fully formed embryos, it can be assumed that newborns are about 9.2-9.6 cm long. Ovulation probably occurs in May and June, and childbirth in August and September. Pregnancy lasts 4 or 5 months, and reproduction has a yearly cycle. The litter contains 6-15 newborns.

Human interaction

Senegalese gnus are not of interest for commercial fishing. They can be caught as by-catch in commercial bottom fisheries. There are insufficient data for the assessment of the conservation status of the species by the International Union for Conservation of Nature.