Leucos ylikiensis

Leucos ylikiensis
Conservation status
Endangered  (IUCN 3.1)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Leuciscidae
Subfamily:	Leuciscinae
Genus:	Leucos
Species:	L. ylikiensis
Binomial name
Leucos ylikiensis (Economidis, 1991)
Synonyms
Rutilus ylikiensis Economidis (ex Stephanidis), 1991

Leucos ylikiensis , the Yliki roach, is a species of is a species of freshwater ray-finned fish belonging to the family Leuciscidae, which includes the daces. Eurasian minnows and related fishes. This species is endemic to Central mainland Greece.

Taxonomy

Leucos ylikiensis first appeared in the literature as Rutilus aula rubella var. ylikiensis in Poissons d'eau douce de l'Atticobéotie published in 1939 by the Greek ichthyologist Alexander I. Stephanidis, but as this name was being applied to a taxon below the level of subspecies it was unavailable under the International Code of Zoological Nomenclature. It was formally described as Rutilus ykiliensis in 1991 by Panos Stavros Economidis with its type locality given as "several lakes in Greece". It is now classified as a valid species in the genus Leucos within the subfamily Leuciscinae of the family Leuciscidae.

Etymology

Leucos ylikiensis belongs to the genus Leucos, this name is derived from the Greek leukos which means "white", the genus was named by Johann Jakob Heckel and he did not explain why he chose this name, it may be that it refers to the silvery colour of Squalius aula. The specific name, ylikiensis, means "belonging to Yliki", i.e Lake Yliki, part of the type locality.

Description

Leucos ylikiensis has 12 soft rays supporting the dorsal fin and 11 supporting the anal fin. The features which distinguish the Achelous roach from other species in the genus Leucos are its moderate size, almost never exceeding 12 or 13 cm (4.7 or 5.1 in), standard length. It is also separable by the lack of a dark midlateral band, the peritoneal membrane being covered in a dense patter of black melanophores and the lateral line having 42 or 43 pored scales. However, the number of gill rakers is the most notable feature with this species having a total of 18 to 20 compared to 8 to 16 in other white roaches. The maximum published fork length for this species is 28.5 cm (11.2 in).

Distribution and habitat

Leucos ylikiensis is endemic to Boeotia in Central Greece where it is found in the Cephissus River and in Lakes Yliki and Paralimni with an introduced population in Lake Marathon reservoir north of Athens. This species is regarded as a relict of the fauna of the large Lake Copais which was drained in the late 19th Century. This species is found in the pelagic zone of the lakes it occurs in.

Conservation

Leucos ylikiensis is classified as Endangered by the International Union for Conservation of Nature and is threatened by habitat degradation by water abstraction and pollution, as well as by overfishing and the introduction of invasive fishes. Climate changed induced extended droughts are also thought to be a threat.