Karyotype, C-band and NOR phenotype of Anatolian endemic fish Squalius anatolicus (Bogutskaya, 1997) (Teleostei, Leuciscidae)

The karyotype and distribution of constitutive heterochromatin and nucleolus organizer regions (NORs) of Anatolian leuciscine endemic to Lake Beysehir, Squalius anatolicus (Bogutskaya, 1997) were analyzed respectively using conventional Giemsa-staining, C-banding and Ag-impregnation. Diploid chromosome number was 2n = 50 and karyotype consisted of 7 pairs of metacentric, 13 pairs of submetacentric, 5 pairs of subtelo- to acrocentric chromosomes, NF value equaled 90. Heteromorphic elements indicating sex chromosomes were not detected. C-banding revealed clear pericentromeric constitutive heterochromatin blocks in several chromosomes. Ag-impregnation revealed the size heteromorphism of NORs that covered almost the entire short arms of the middle-sized submetacentric chromosome pair. The karyotype pattern and simple NOR phenotype of S. anatolicus are nearly identical with that found not only in Squalius species analyzed to date but also in many other representatives of the Eurasian leuciscine cyprinids, which indicates remarkable chromosome stasis in this leuciscid lineage.

Population Structure and Some Growth Properties of Gibel Carp (Carassius gibelio) in a Mesotrophic Lake

The hereby study investigated gibel carp (Carassius gibelio) in a mesotrophic lake (Lake Beyşehir, Turkey) from April 2013 to March 2014, in order to outline population structure and some growth properties of the species. Two water quality variables (Chlorophyll-a, Trophic State Index (TSI)) were detected seasonally to define trophic status of the lake. Length and weight distributions, length - weight relationship, sex ratio, gonadosomatic index (GSI), condition factor (CF) and von Bertalanffy equation were calculated for C. gibelio sampled monthly. Trophic status of the lake was defined as mesotrophic. Total length and weight of C. gibelio samples was determined in the range of 8.5 and 28.4 cm and 15 and 408 g, respectively. Mean total length and weight of individuals were calculated as 17.5 ± 2.37 cm and 88.6 ± 39.02 g, respectively. There was a negative allometry between length and weight for C. gibelio. The fish samples were composed of 52% females and 48% males, between II and VII years old. Spawning period of the species occurred between April and June after GSI values reached their maximum in March. The CF values were validated between 1.5-1.7 besides the mean rate of females and males were 1.6 and 1.5, respectively. The parameters of von Bertalanffy equation were calculated as L∞: 19.8 cm, W∞: 652.9 gr, k: 0.934. In conclusion, C. gibelio has almost lost the economic value since the individuals are smaller than market size (≥ 250 g), probably due to lack of nutrients/mesotrophic situation of Lake Beyşehir.