Genetic variability and phylogeography of the cyprinid Telestes muticellus within the Italian peninsula as revealed by mitochondrial DNA

A phylogeographic analysis of 12 populations of Telestes muticellus was performed on the basis of mitochondrial DNA sequences of the cytochrome b gene. The main aims were to determine phylogenetic relationships from congener species and to highlight the patterns of genetic differentiation within the Italian peninsula. The results obtained showed a significant divergence with the congener species, indicating a possible Miocene origin for the genus. Divergence was found to be low for T. muticellus , yet distinct lineages resulted as being allopatric within the two main Italian biogeographic districts, the Padano-Venetian and the Tuscano-Latium, suggesting the existence of recent vicariance coupled with past demographic regression. The high level of genetic differentiation found between populations highlighted the low dispersal ability of this rheophilic Cyprinid, whose migration was mainly related to connections between the upper parts of river basins. The distribution of sequence characteristics found suggests that particular attention should be paid to the conservation management of this species.     

Early development of the endemic dace Telestes karsticus (Leuciscidae,Cypriniformes) in a Dinaric karst stream in Croatia

Early development of the endemic dace Telestes karsticus is described in a Dinaric karst stream in Croatia. Larvae were acquired from successful rearing in an aquarium. Basic morphometric and meristic measures of larvae were taken during 55 days of observation. The mean total length of larvae at the time of hatching was 6.45 mm. The yolk sac was completely absorbed in all larvae by day 9 post-hatching (PH), when the mouth also opened and independent feeding and intestinal function were observed. Flexion of the urostyle was completed between days 12–16 PH. The caudal fin became completely forked on day 23 PH. Formation of fin rays was complete on day 48 PH when fish fully resembled juvenile specimens. The number of soft ray fins corresponds to the adult. Understanding the early development is particularly valuable in assessing environmental impacts and recovering of this endangered species and it is essential for effective monitoring and its conservation. This is the first report of the early development for the endemic Telestes karsticus, pointing out the importance of the obtained results for the effective conservation of the species.     

A new endemic cyprinid species from the Danube drainage

Populations of endemic Croatian dace were found to belong to two different species, one of which is first described in this study. Telestes karsticus sp. nov. differed morphologically from Telestes polylepis in the total count of lateral line scales, number of gill rakers and the shape of the posterior margin of the anal fin. Morphological differences were corroborated with mtDNA analyses (with p-distance between T. polylepis and T. karsticus sp. nov. ranging between 3·2 and 4·1%; and the number of substitutions between 37 and 47). The newly described species is geographically very localized. It has been recorded from only four localities around Velika Kapela and Mala Kapela mountains in Croatia.     

Tyrrhenian basins of Ligury as a new peri-Mediterranean ichthyogeographic district? Population structure of <Emphasis Type="Italic">Telestes muticellus</Emphasis> (Osteichthyes,Cyprinidae), a primary freshwater fish

The phylogeographic structure of vairone (Telestes muticellus), a primary freshwater fish endangered in a large part of its distributional range, was assessed: (i) to reconstruct the complex dispersion pattern in the upper Tyrrhenian hydrographic basins of Ligury, actually not recognised as peri-Mediterranean ichthyogeographic district, and (ii) to evidence the shape of population genetic structure as useful tool for future conservation strategies. A partial fragment of mitochondrial DNA cytochrome b (497 bp) was sequenced in 109 specimens sampled from eight populations, along an east–west geographic gradient. Fourteen haplotypes were identified, confirming the evolutionary distance between the two co-generic species: T. muticellus as ‘Ligurian’ clade and T. souffia as ‘French’ clade. The Nested Clade Analysis (NCA), the population genetic variability and population structure suggested a natural colonization occurred throughout the crossing of Alpine and Apennine watershed. The hierarchical Analysis of Molecular Variance (AMOVA) confirmed a geographic distinction between the populations from western (WTL) and from eastern (ETL) Tyrrhenian basins of Ligury colonised through the river capture processes along the Maritime Alpine watershed (Padano-Venetian district) and along the Apennine watershed (Tuscano-Latium district), respectively. Our results, evidencing the lack of genetic contiguity among vairone populations of the upper Tyrrhenian hydrographic basins of Ligury, allowed to recognise the presence of two management units (MUs) for its conservation. Handling editor: Christian Sturmbauer