Dwarf false catshark
Planonasus parini is a shark from the family of Pseudotriakidae, which was first described in early 2013. The first copy, at the same time the holotype of the species, was caught in the years 1988/89 by the Russian research vessel Vityaz near the island of Socotra in the northwestern Indian Ocean, two more some time later by commercial trawlers in the same area. The name of the previously monotypic genus refers to the flat snout of the species (Latin " planus " = flat, " nasus " = nose). The Style epithet honors parini NV Parin the chief scientist on the 17th voyage of the Vityaz in which the holotype was caught.
Features
Planonasus parini is a small shark, the holotype, a female, is 53 cm long and weighs 560 g The other two known specimens have a length of about 35 cm. Magnetic resonance images of the holotype show that there is an adult specimen and it is assumed that the maximum size is 56 cm. The head is relatively long, the nose flat and moderately long. The very large mouth opening is bell-shaped. A portion of the teeth in the upper jaw forms a closely spaced tooth comb, others are three or fünfspitzig. Almost all of the mandibular teeth are comb-shaped. The labial are short. The front folds of skin at the nostrils are short, the inner width. The entire palate is densely covered with papillae of various sizes. The spray holes are very large and are approximately perpendicular. Its length is the 4 to 6 times and its height reaches 2 to 5 times the eye diameter. The first dorsal fin has the shape of a long, flat triangle with rounded upper tip and a narrow free end. It lies between the chest and abdominal fins. A Interdorsalkamm missing. The second dorsal fin is much higher than the first, has the shape of an irregular triangle, opposite the small anal fin. The caudal peduncle is relatively short and without keels. Planonasus parini is colored dark gray - brown, the sides of the body, the underside of the head and the edges of the fins are darker, the free tip of the first dorsal fin is white.
Of the other sharks of the family Pseudotriakidae to Planonasus parini differs by a lower number of vertebrae, a longer head, the lack of a nictitating membrane and the presence of Oralpapillen. Compared with Gollum and Pseudotriakis Planonasus parini has a middle position with regard to the length of the muzzle, the number of teeth per row of teeth, the height of the first dorsal fin, the length and width of its free rear portion and the caudal peduncle.
Way of life
The life of Planonasus parini is completely unknown but probably similar to that of other pseudotriakider sharks. Body shape, fins, skin and muscles have a bottom-dwelling, sluggish, slow movements with anguilliformen floating and largely inactive Hai suspect.
System
Planonasus parini belongs together with three other previously described extant species of the family Pseudotriakidae within the order of ground sharks ( Carcharhiniformes ). A similar undescribed species was caught in the Maldives and could be the next of kin of Planonasus parini be.