Thursday 23 August 2012

A new species of Toothcarp from Iran.

The Toothcarps of the genus Aphanius are the only Eurasian members of the Family Cyprinodontidae; all other members of the family are restricted to the Americas, where they are variously known as Pupfish, Flagfish and Killifish (the term Killifish is also used to describe a number of Fish in other families; some members of the genus Aphanius are also called Killifish). Toothcarp are small carnivorous fish found in rivers and ponds across southern Europe, North Africa and southwest Asia; they are not closely related to true Carp.

In a paper published in the journal ZooKeys on 17 August 2012, a team of scientists led by Azad Teimori of the Department of Earth and Environmental Sciences at Ludwig-Maximilians-University, and the Department of Biology at the Faculty of Sciences at Shahid-Bahonar University of Kerman, describe a new species of Toothcarp from Namak Lake basin in Markazi Province in north-central Iran.

The new species of Toothcarp was discovered during fieldwork in 2007 in a shallow pond in the Namak Lake basin, 5 km south east of the city of Arak. The pond was roughly  4 × 6 m, and fed by drainage from a natural spring. The water was warm (23℃), and semi-stagnant. The pool had a muddy bottom with some gravel and lacked vegetation; the surrounding area was dominated by Rushes and Bulrushes. The new Fish was the only species present, it was also found in a number of nearby springs.

The pool in which the new species of Toothcarp was discovered. Teimori et al. (2012).

The new species is named Aphanius arakensis, the Arak Toothcarp, it is a 22.5-38.5 mm fish that was identified as a probable new species on the basis of the distinctive male colouration (dark grey with blue bars, the females are grayish), and this was later confirmed on the basis of otolith (ear-bone) morphology and gene sequencing.

Aphanius arakensis. (Top) male. (Bottom) female. Teimori et al. (2012).

The number of species of Aphanius in Iran has increased rapidly in recent years, since it has been discovered that differences in male colouration usually reflect different species, suggesting that sexual selection is the major driver of speciation in the group here (and probably elsewhere). It is highly probable that more species will be described in the group in the near future.

Map showing the distribution of endemic Aphanius species in Iran. Teimori et al. (2012).

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