Utku Güner

Induction of micronuclei and nuclear abnormalities in erythrocytes of mosquito fish (Gambusia affinis) following exposure to the pyrethroid insecticide lambda-cyhalothrin

In the present study the induction of micronuclei (MN) and nuclear abnormalities (NA) in erythrocytes of mosquitofish (Gambusia affinis) (Baird & Girard 1853) was studied. Fish were exposed to three different concentrations of lambda-cyhalothrin (LCT) (1×10(-4)μg/l, 2×10(-4)μg/l, 4×10(-4)μg/l) for periods of 6, 12, 24, and 48h. NA (notched, lobed, blebbed nuclei), MN, bi-nucleated cells, and the ratio of polychromatic erythrocytes (PCEs) to normochromatic erythrocytes (NCEs) were evaluated to assess genotoxicity and cytotoxicity. LCT significantly induced MN and NA in erythrocytes of G. affinis. The PCE/NCE ratio was also decreased after 24- and 48-h treatments of 4×10(-4)μg/l LCT. The results show that LCT has genotoxic and cytotoxic potential on G. affinis.

Status of Freshwater Crayfish Distribution in Thrace Region of Turkey

This review focuses on the present distribution of two crayfish species: narrow-clawed crayfish Astacus leptodactylus Eschscholtz and stone crayfish Austropotamobius torrentium (Schrank, 1803) in Thrace region of Turkey. The only known native (indigenous) freshwater crayfish species of Turkey is A. leptodactylus. It is found at more sites than A. torrentium. On the other hand, A. torrentium is only found in Thrace region of Turkey. The first population of A. torrentium was observed in Velika River in 1995. In 2006, the second population of A. torrentium was found in Madara Brook in the region, but the abundance of A. torrentium in Madara Brook was very low in comparison to Velika River. Moreover, further studies carried out in some water resources near the population of A. torrentium, such as De[vgrave]irmen Brook, Poyralı Brook, and Hasköy Brook confirmed that no other populations of this species are present in the region at present. Therefore, it can be concluded that A. torrentium is only present in the northwest of Marmara river basin (Istaranca Mountain Part) and A. leptodactylus is widely distributed throughout the places located to the south of Marmara river basin, and Istaranca Mountain might be a border line that separates A. leptodactylus and A. torrentium populations. Moreover, except the presence of these two species, no other crayfish species are found in the Thrace region of Turkey at present.