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.
The common gudgeon Gobio gobio (L.) has a great phenotypic plasticity being one of the most variable fish species in Europe. In the Iberian Peninsula it has been considered to be an introduced species. However, recent publications have considered that gudgeon populations from different basins of the Iberian Peninsula are native. in this work we tried to clarify the status of Iberian populations by means of molecular methods. thirty-two specimens of common gudgeon from several localities placed in six different Iberian and South French basins (Duero, Ebro, Tajo, Nansa, Bidasoa and Nivelle) were analysed. We reconstructed the phylogenetic relationships between the Iberian gudgeon populations using the whole cytochrome b gene sequence (1141 bp). Moreover, one specimen of G. gobio from the Danube basin and two specimens of Ramanogobio (R. ciscaucasicus and R. uranoscopus) were also included in the study. Our data confirmed the monophyly of the Iberian-French populations analysed and indicated a high genetic differentiation with respect to the common gudgeon populations from Central Europe. However, our results also indicated a very close genetic relationship among the populations of different Iberian basins, showing low genetic distances between them. The absence of population structure among the Iberian populations of G. gobio seems to be due to human activity.
Morphometric variation in Aphanius iberus was analysed to demostrate the remarkable genetic divergence between Mediterranean and Atlantic population of Iberia. Four discrete morphotypes in males and three in females were distinguished. Morphometric data discriminated the Atlantic and Mediterranean populations, but revealed the Villena population as the morphologically most differentiated. Atlantic populations were described as a new species, Aphanius baeticus sp. nov., which differs from A. iberus in the overall shape, coloration pattern and number of branched rays on the dorsal and anal fins. The Villena population was retained in A. iberus because, despite of its morphological differentiation, show high genetic introgression at the nuclear genome with neighbouring populations. The range of A. baeticus sp. nov. is restricted to the eight localities of the Atlantic slope of the Iberian Peninsula. This new species should be considered Critically Endangered (CR) according to the IUCN Red List Categories.