Tanja Mihinjač

FIRST RECORD OF THREE-SPINED STICKLEBACK (Gasterosteus aculeatus Linnaeus, 1758) IN THE DANUBE BASIN OF CROATIA

The three-spined stickleback (Gasterosteus aculeatus Linaeus, 1758) is a small teleost fish considered to be one of the most widely distributed freshwater fishes in the world (Morrow, 2008). In the northern hemisphere, sticklebacks are absent only along the Arctic coasts of Siberia and North America (Mrakovcic et al., 2006). In Europe they often form highly abundant populations, and in some ecosystems are dominant (Clavero et al., 2009). Three-spined sticklebacks are listed as a species of Least Concern (LC) in the European IUCN Red List (Freyhof et al., 2008). However, freshwater populations in the Mediterranean region have experienced a sharp decline or even local extinction events (Clavero et al., 2009). Despite their wide global distribution, stickleback populations in Croatia are present in a fragmented distribution in isolated rivers of the Adriatic Basin: the Krka River (Visovac Lake), Neretva River catchment and Mirna River catchment on the Istrian peninsula (Mrakovcic et al., 2006; Zanella, 2009; Zanella et FIRST RECORD OF THREE-SPINED STICKLEBACK (Gasterosteus aculeatus Linnaeus, 1758) IN THE DANUBE BASIN OF CROATIA

THREATENED FISHES OF THE WORLD: Delminichthys krbavensis (Zupani and Bogutskaya, 2002) (Cyprinidae)

Krbava minnow, Delminichthys krbavensis, is freshwater fish species of endemic to the Adriatic watershed in Croatia. It lives only in karstic springs, streams and subterranean waters in Krbavsko polje. This species is protected by Croatian law and it is listed on IUCN Red List as Critically Endangered (CR). D. krbavensis has very limited distribution what makes it vulnerable to different kinds of threats such as water extraction, exploitation of karstic springs and streams, agricultural pollution, road construction and introduction of nonindigenous fish species. Suggested conservation actions for this species are detailed study of biology, ecology and distribution as well as bans on watercourse regulation and road construction, reduction of pollution and restriction of introductions of nonindigenous fish species. Also, conservation of this species should be ensured through implementation of management and action plans.

Threatened fishes of the world: Phoxinellus pseudalepidotus Bogutskaya & Zupančič, 2003 (Cyprinidae)

Mostar minnow, Phoxinellus pseudalepidotus, is freshwater fish endemic to the Neretva River drainage. Present data suggest that species is restricted only to wetland of Mostarsko Blato but it is considered to be distributed more widely in River Neretva basin. It is threatened because of the extremely limited range of distribution, river regulation and influence of the non-indigenous species. Suggested conservation actions for Mostar minnow are habitat protection and establishing of the nature reserve in the area of Mostarsko Blato. Stocking with translocated and nonnative species should be also banned.