R. TENCHE-CONSTANTINESCU, A. TENCHE-CONSTANTINESCU, C. L. MOSNEANG, R. T. CRISTINA, F. BORLEA. THE IMPACT OF HYDROTECHNIC CONSTRUCTIONS ON THE GENETIC VARIABILITY OF CHONDROSTOMA NASUS POPULATIONS IN BEGA AND TIMIS RIVERS. SGEM2016 Conference Proceedings, Book 5(2), pp. 841-848, 2016.
Out of the 20 currently recognized species in the genus Chondrostoma, several have a very restricted range, being very rare nowadays and at least one species is globally extinct. The nase Chondrostoma nasus (Linnaeus 1758), most frequently encountered species of genus Chondrostoma, belongs to reophilic fish species, whose population in the wild water decreased in the last decades mainly because of the dam building, destruction of spawning sites, pollution, loss of suitable gravel bottom. Massive population decline of the nase was registered in Germany, Austria, Switzerland, Czech Republic and Poland. C. nasus is on the IUCN Red List at the criteria Least Concern (LC) because it is considered that the nase is widespread but locally threatened. C. nasus is one of the most representative species in Bega and Timis rivers (Western Romania), an important angler-target species, being able to adapt in these lightly polluted waters. This gregarious species feeds on the perifiton which is abundant in these waters, preferring free flowing sections, requires high habitat variability and depends on riparian vegetation for adequate spawning grounds. The genetic variability of C. nasus geographically distinct population groupings in an area affected by hydrotechnic constructions were described using ISSR (Inter Simple Sequence Repeat) markers in order to define species conservation strategy in the present day context. The morphological characters analysis requires a more in-depth research in order to describe the local adaptation of nase. The impact of double connection Timis-Bega on C. nasus populations is important especially because of the fragmentation of the area and the blocking of the migration routes in the reproduction period.
Chondrostoma nasus, ISSR markers analysis, genetic variability, flow fragmentation, population decline
Romeo Teodor Cristina