Sibel Özesen Çolak

This study presents the first data on parasites of the chocolate chub, Squalius carinus Özuluğ & Freyhof,
2011. The composition and the structure of the parasite community infecting this endemic fish from the
Işıklı Lake are described. A total of 54 specimens of S. carinus are examined; 51 (94.4%) infected by at
least one parasite species. In total, 1192 parasite individuals are collected, with mean intensity of 23.4
and mean abundance of 22.1 parasites/fish. The parasite community of S. carinus consists of 14 species:
Trichodina sp., Ichthyophthirius multifiliis, Chilodonella cyprini (Protozoa); cysts of Myxobolus sp.
(Myxozoa); Dactylogyrus vistulae, Gyrodactylus sp. (Monogenea); Bothriocephalus acheilognathi (Cestoda),
metacercariae of Diplostomum sp. and Thylodelphys clavata (Digenea); larvae of Nematoda indet.
(Nematoda), Pomphorhynchus sp. (Acanthocephala); Lamproglena pulchella and Lernaea cyprinacea
(Crustacea); and glochidia of Mollusca indet. (Mollusca). The highest dominance index among parasites
is recorded for Pomphorhynchus sp. (47.9%), and the lowest for Nematoda indet. (0.3%). The mean
species richness of parasite infracommunities is 2.3 species per individual fish. The parasite community
of S. carinus is dominated by Pomphorhynchus sp. The remaining parasite species are found with low
prevalence and abundance, except for Diplostomum sp. and Dactylogyrus vistulae, which are moderately
abundant.

Metazoan parasites of European eel (Anguilla anguilla) were investigated between December 2009 and March 2010 in the Köyceğiz-Dalyan estuarine channel system in Turkey. A total of 73 A. anguilla were examined. In two fish (2.7%), no parasites were found. In the others, eight parasite species were found: Pseudodactylogyrus anguillae, Digenea gen. sp., Bucephalus anguillae, Acanthocephalus clavula, Anguillicoloides crassus, Tetraphyllidea gen. sp., Ergasilus gibbus and Ergasilus lizae. Most of the eels had two (37.0% of eels), three (31.5%) or one (15.1%) parasite species. Prevalence and mean intensity of the parasite species were: P. anguillae, 82.2%, 24.6; E. gibbus, 52.1%, 4.0; A. crassus, 39.7%, 3.3; E. lizae, 26.0%, 3.4; B. anguillae, 15.1%, 7.5; Digenea gen. sp., 11.0%, 9.0; A. clavula, 6.8%, 1.8; and Tetraphyllidea gen. sp., 1.4%, 3.0, respectively. P. anguillae and B. anguillae are new records for Turkey.

A total of 366 specimens of 10 fish species inhabiting Lake Sığırcı were examined between April 2009 and February 2010.
Inside or outside of these fish, 33 parasite species were identified. From these parasites, 18 monogenean, 5 digenean trematode, 3 cestode, 3 acanthocephalan, 3 nematode, and 1 Mollusca: Bivalvia (glochidia) species were recorded. Diplostomum spp., Tylodelphys clavata, glochidia-larvae, and monogenean species were found to be common parasites in all the fish species examined. The highest prevalence and mean infection intensity with Diplostomum spp. were found in Lepomis gibbosus (prevalence 91.6%, mean intensity 5.6 individuals per fish) and in Scardinius erythrophthalmus (prevalence 88.0%, mean intensity 73.0 individuals); Tylodelphys clavata occurred with the highest prevalence (98.2%) and mean infection intensity (181.3 individuals) in Perca fluviatilis. Carassius gibelio exhibited rich monogenean biodiversity, with 6 species.

Metazoan parasites of the sand smelt Atherina boyeri Risso, 1810 in Lake Iznik were studied. A total of 271 specimens of A. boyeri, 208 female and 63 male, mean (±SD) total length 8.4 ± 2.2 cm (range 3.1–12.2 cm) and mean total weight 4.7 ± 3.5 g (range 0.1–11.7 g) were examined between June 2008 and May 2009 at monthly intervals. In 33 fish no parasites were found. In the other fish, four parasite species were recorded: Diplostomum sp. (prevalence 39.13%, mean intensity 3.50 ± 3.03); Tylodelphys clavata (prevalence 74.16%, mean intensity
10.41 ± 14.89); Bothriocephalus cf. acheilognathi (prevalence 40.59%, mean intensity 31.83 ± 57.74); and Eustrongylides excisus (prevalence 6.64%, mean intensity 1.16 ± 0.39). The mean abundance of Diplostomum sp., T. clavata and E. excisus was higher during the winter and early spring months. In contrast, the mean abundance of B. cf. acheilognathi was higher in the summer and autumn months. This distribution of the parasites was related to a change in the environment of A. boyeri from the pelagic zone to deeper water at the end of autumn and a change in food supply.

The freshwater crayfish (Astacus leptodactylus Eschscholtz, 1823) is a valuable and protected invertebrate species and the only native and dominant species in the big lakes of Turkey, such as Iznik Lake (Bursa, Turkey). In this study, bioaccumulation of some heavy metals (Zn, Cu, Cd, Pb) in abdominal muscle tissue of Astacus leptodactylus samples collected between November 2008 and December 2009 was examined. Heavy metal contents in muscle tissues were measured by AAS analysis. According to the obtained data, the levels of Zn, Cu, Cd and Pb for the studied samples were within normal ranges, and lower than all the recommended legal limits. The descending order of heavy metal concentrations found in crayfish is Zn>Cu>Cd>Pb. Heavy metal concentrations in freshwater crayfish samples were compared with the maximum permitted levels of heavy metals in seafood regulated by the EU, FAO and Turkish Food Codex limits. The results showed that there was no serious hazard in the samples in terms of the Zn, Cu, Cd and Pb values analyzed from Iznik Lake, Bursa, Turkey.