Stygichthys typhlops

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Stygichthys typhlops
Systematics
Sub-cohort : Ostariophysi
Otophysa
Order : Tetras (Characiformes)
Family : True tetras (Characidae)
Genre : Stygichthys
Type : Stygichthys typhlops
Scientific name of the  genus
Stygichthys
Brittan & Böhlke, 1965
Scientific name of the  species
Stygichthys typhlops
Brittan & Böhlke , 1965

Stygichthys Typhlops is a blind and non-pigmented species from the family of Real tetras . It is the only species in the genus Stygichthys . The occurrence is limited to the Brazilian state of Minas Gerais .

features

Dimensions are only available from the holotype collected in 1962 . The total length of the animal is 23.6 mm. The body is slightly elongated. Head height and width are similar. In the right intermaxillary bone there are seven teeth on the inner of two rows of teeth. The outer row of teeth of the intermaxillary bone consists of three teeth. In the upper jaw there are ten teeth and lower jaw eight. Two very small nostrils can be seen on the upper lip of the tip of the snout. A second, much larger pair of nostrils is at the top of the muzzle just before the browbones rise. The skin is completely unpigmented and there are no noticeable lateral line organs and no externally visible eyes. There are seven dorsal rays, eight anal rays, ten pectoral rays, five ventral rays, and fifteen caudal rays.

Occurrence and habitat

The exact type locality is unknown. It is located in a well near Jaiba. Jaiba can refer to the entire region (Serra de Jaiba) as well as to the city of Jaiba, which lies between Januária and Janaúba in northern Minas Gerais. Stygichthys typhlops lives in the groundwater.

Way of life

Even if the tooth structure suggests a vegetarian diet, it is unlikely that this species would eat plant-based foods in an underground environment. The teeth are believed to be a holdover that Stygichthys typhlops inherited from an unknown ancestor. Cannibalism is not unknown.

status

For a long time, Stygichthys typhlops was known only from one specimen that was caught in May 1962 by Joseph A. Tosi junior, an ecologist from the Instituto de Agricultura of the Organization of American States, during a well construction project at a depth of 30 meters. It was not until 2004 that researchers from the Instituto de Biociências and the Zoological Museum of the University of Sâo Paulo discovered 25 more specimens. The IUCN classifies the species in the “ data deficient ” category . The main hazard is the lowering of the groundwater level.

literature

  • Aldemaro Romero & Amy McLeran: Threatened fishes of the world: Stygichthys typhlops Brittan & Böhlke, 1965 (Characidae) . Environmental Biology of Fishes 57: p. 270, Kluwer Academic Publishers. Printed in the Netherlands. 2000
  • Francisco Alexandre C. Sampaio, Paulo Santos Pompeu & Rodrigo Lopes Ferreira: Notes on Stygichthys typhlops (Characiformes; Characidae): characterization of their teeth and discussion about their diet . In: 2012 Speleobiology Notes 4: S. 1-5 PDF, online

Web links