In July 2004 and 2006, tributaries of the River Neretva and surrounding karstic fields (polje) in Bosnia and Herzegovina were sampled, and new data on spined loaches (Cobitis) and accompanying freshwater fish fauna gathered. spined loaches were found in the River Bregava and Hutovo blato wetland, which are directly connected to the River Neretva, in the River Trebišnjica in Popovo polje, in Lake Krenica and the River Matica in Imotsko polje, and in the River Lištica drainage in Mostarsko blato. However, Cobitis were not found in karstic fields situated more westward (Livanjsko polje, Duvanjsko p., Kupreško p. and Glamočko p.), nor in karstic fields situated northward from the River Trebišnjica (Nevesinjsko polje, Fatničko p., Dabarsko p. and Gatačko p.). Neither were they found in the River Trebižat, which lies closer to the River Neretva than does Imotsko polje. Based on morphological and molecular characters, spined loaches inhabiting the rivers Trebišnjica and Bregava, and Hutovo blato were identified as Cobitis narentana Karaman, 1928, while specimens from Imotsko polje and Mostarsko blato were classified as Cobitis sp. Until now, a single species of spined loach, C. narentana, had been recorded from the lowermost part of the River Neretva basin. Our new findings suggest that the species diversity of the spined loaches in the Neretva basin in Bosnia and Herzegovina might be underestimated and that a detailed taxonomic study is required to determine the Cobitis diversity in this area.
Between 2003 and 2006, almost 80 localities in all main hydrological systems in Albania were sampled and data on the distribution of loach fishes gathered. The spined loach Cobitis ohridana Karaman, 1928 was found to be a common species in Albania, occurring in most of its river systems, from the Ohrid-Drin-Shkodra system in the east and north to the River Vjosë basin in the south. Cobitis meridionalis Karaman, 1924 occurs in Lake Prespa, while a spined loach with mtDNA of Cobitis sensu stricto origin is present at least in the Ohrid-Drin-Shkodra system. The most common stone loach in Albania was found to be Oxynoemacheilus pindus (Economidis, 2005). It was caught in the basins of the rivers Vjosë, Seman, Shkumbin and Erzen. Barbatula sturanyi (Steindachner, 1892) was recorded in the River Black Drin.
Inter-population variability within Sabanejewia populations from the western Balkans, and their phylogenetic position in comparison to other European populations were investigated. Of 79 samples analysed, 51 unique haplotypes were identified. Network analysis divided thirteen populations from five river basins into two clusters: cluster I was composed of populations from the Vardar drainage and tributaries of the neighbouring River Morava (River Danube basin), while cluster II contained the River Timok (eastern Serbia) and all the River Sava populations. The only locality that housed haplotypes of both clusters was the River Kutinska reka in the upper Morava basin. When compared with the haplotypes reported in former studies, both clusters fell within the ‘Danubian-Balkanian complex’. Cluster II was included in the most heterogeneous sub-lineage S. montana – S. bulgarica – S. balcanica (III), while cluster I was related to the sub-lineages S. doiranica – S. balcanica (II) and S. balcanica (VI). Recently published haplotypes from the Croatian Sava (rivers Petrinjčica and Rijeka) and Drava (rivers Drava and Voćinska) basins, as well as Czech and Slovak individuals from the Danube and Tisza river basins were included. The River Drava showed the same population subdivision as the River Kutinska reka.
The genetic differentiation of Oxynoemacheilus bureschi (Drensky, 1928) from all three drainages (Struma=Strymon, Mesta=Nestos, Vardar=Axios) where this species occurs, as well as its phylogenetic relationships with other European stone loaches, was assessed using the mitochondrial cytochrome b gene. The phylogenetic reconstruction revealed two distinct clades within the European stone loaches with high bootstrap values. Very low genetic variability with no internal haplotypic structure has been found between and within all examined O. bureschi populations, indicated by low polymorphism and similar haplotypes. According to the nesting design and demographic patterns, the range of O. bureschi was not constant, but underwent expansion in the recent past. Lack of variation, a rather unusual phenomenon for fishes from the southern Balkans, is ascribed to facilitation of dispersal due to seashore regression, confluence events and river capture during the Pleistocene.
The morphometric, meristic and phenotypical characters of the members of the genus Alburnus from the Adriatic Basin were analyzed on specimens from 11 localities, representing eight watersheds. The number of gill rakers, the number of lateral line scales, the number of branched anal fi n rays and the coverage of the ventral keel by scales have the greatest signifi cance in differentiating between species. Signifi cant morphological differences exist between the Alburnus population from Lake Lugano (type locality for Alborella maxima Fatio, 1882) and all the remaining investigated populations. Alburnus from the Neretva River drainage is described as a new species and it is distinguished from other species of the genus Alburnus by the following combination of characters: 131/2-151/2 branched anal fi n rays; 17-26 gill rakers; 40-48 lateral line scales; fi rst anal fi n ray below branched dorsal rays 6-10 or located up to one scale after the last dorsal fi n ray; ventral keel exposed for at least 2/3 of a distance between the pelvic fi n base and the anal aperture. The status of the Neretva River basin populations as a separate species was corroborated by genetic analyses, with p-distance between newly described species and A. arborella from the Zrmanja River 1.8-2.2%.
The occurrence of common gudgeon in the River Morača drainage of southern Montenegro was investigated. Low numbers of specimens were recorded in four out of five localities investigated on the Zeta River and at a single locality on the lower part of the River Morača. Allozyme analysis revealed that the specimens examined belong to the species Gobio gobio (Linnaeus, 1758). The lower number of lateral line scales in common gudgeon from the Ohrid-Drim-Skadar system, as compared with other European populations, probably indicates clinal variability. The results also demonstrate that the subspecies Gobio gobio ohridanus Karaman, 1924 is not a valid taxon.
Morphological differences between female and male spined loaches belonging to five species from the Adriatic basin were examined. Besides the presence of the Canestrini scale and the length of the pectoral fins, sexual dimorphism is also visible in the position of the pectoral fins, as well as in the length of the pelvic fins. Both pectoral and pelvic fins are significantly longer in males than in females, whereas pectoral fins of females are located more anteriorly then in males. Differences in the length of pectoral and pelvic fins among species are also revealed. The role of the secondary sexual characters in males is probably connected with their special mating behaviour. Furthermore, a hypothesis that habitat conditions have greater impact on body dimensions of females than males is proposed.