Cobitis  (Cobitis narentana)

Cobitis narentana is classified as Vulnerable (VU) on the IUCN Red List (1).

Endemic to the Neretva River basin of Croatia and Bosnia-Herzegovina, Cobitis narentana is a peculiar-looking freshwater fish with a long body and a small head (2). The eyes are close to the snout, and the mouth is arched, with three pairs of long barbels. The lips are finely furrowed. The male Cobitis narentana is smaller than the female, but tends to have longer pectoral fins (3). 

The body of Cobitis narentana is patterned by a row of distinct squarish blotches, and there is as a dark, comma-shaped spot on the upper lobe of the tail fin (2) (4). There is also a small oval spot on the lower lobe of the tail (2).

Cobitis narentana is only found in the Neretva River Basin in Croatia and Bosnia-Herzegovina (1) (2).

A freshwater species, Cobitis narentana occurs in slow-flowing rivers, lakes and marshes, where it prefers sandy or silty substrate and dense vegetation (1) (2).

Cobitis narentana is a rare species with a restricted distribution, and very little is known about its biology and behaviour. However, it is thought to spawn between April and August, when up to 2,500 eggs may be released by the female (2) (4). It is a short-lived species, with most males dying before three years of age, although females usually live to five. Cobitis narentana reaches maturity when it is around 5.8 centimetres in length (5). 

Restricted to just a single river system, Cobitis narentana is at risk from pollution and habitat loss (1). Water extraction and sand and gravel mining are degrading rivers, and run-off from agriculture is polluting the water (2). The introduction of alien species, including pike-perch (Sander spp.) and rainbow trout (Oncorhynchus mykiss), also threatens Cobitis narentana (2), while the proposed construction of the Neretva dam will decrease water flow in its habitat, increasing the frequency of drought. The latter threat could be exacerbated by global climate change (1).

Cobitis narentana has not been the target of any known conservation measures. However, it has been recommended that the River Neretva is designated a protected area as part of the Natura 2000 network (7).

Find out more about Cobitis narentana:

• Zanella, D., Mrakovčić, M., Mustafić, P., Ćaleta, M. and Marčić, Z. (2009) Threatened fishes of the world: Cobitis narentana Karaman, 1928 (Cobitidae). Environmental Biology of Fishes, 86: 523-524.