Three species of the Eurasian family Cobitidae are distributed in Slovakia. In the present paper, we describe the coenological affinity of Cobitis elongatoides, Sabanejewia balcanica and Misgurnus fossilis in two distinct zoogeographical regions, Slovak Tisza and Danube basins and discuss possible differences of their biotop affinity and habitat preferences. The occurrence of S. balcanica is restricted to primary biotopes with harder substratum particles. Typical species assemblages for the rheophilic C. elongatoides are eurytopic and limnophilous species. C. elongatoides is mostly distributed in primary biotopes, such as rivers and channels. It also occurs in secondary biotopes (drainage canal or pit). M. fossilis is distributed mostly in the secondary biotopes, but it is also found in the primary biotopes. Both species prefer fine substratum, but spatial distribution of the two species is different. C. elongatoides prefers harder substratum of sandy particles mixed with mud or detritus and living vegetation, whereas M. fossilis prefers muddy substratum mixed with detritus and dead vegetation.
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.
Morphology features and sequences of mitochondrial cytochrome b (cyt
b) gene were analyzed of the species Cobitis Linnaeus, 1758 from the River Pearl basin of China. Three new species of C. leptosoma sp. nov., C. wumingensis sp. nov.,and C. obtusirostra sp. nov. were described. C. leptosoma is distinguishable from its congeners by a long knife-shaped lamina circularis; a sharp and nearly filamentous tip of the pectoral-fin ray in males; four Gambetta pigment lines, L2 usually being absent, L5 consisting
of 10-12 oval blotches; and a round or oblong spot smaller than or equal to the eye diameter on the upper part of the caudal peduncle. C. wumingensis
is distinguishable by small barbels, maxillo-mandibular barbels shorter than eye diameter; a long fingerlike lamina circularis; a sharp and nearly filamentous tip of the pectoral-fin ray in males; L5 showing sexual dimorphism; a deeper bluish band pigment in females; a surface pigment with 13-14 blotches in males; and a conspicuous jet-black roundish spot smaller than or equal to the eye diameter on the upper part of the caudal peduncle.
C. obtusirostra is distinguished by a cystiform lamina circularis; a sharp and
nearly filamentous tip of the pectoral-fin ray in males; L5 consisting of 8-10 rounded blotches; and a conspicuous jet-black arcuate spot smaller than the eye diameter on the upper part of the caudal peduncle.