The relationships between size (length and width) of the lagenar (asteriscus) and the utricular (lapillus) otoliths and body length for five cyprinid fish species, freshwater bream Abramis brama, white bream Blicca bjoerkna, Prussian carp Carassius gibelio, brond-snout Chondrostoma regium, and rudd Scardinius erythrophthalmus, collected from Lake Ladik from November 2009 through October 2010, are presented. The right and left side measurements of otoliths were pooled in all cases except asteriscus length in Prussian carp. Nonlinear and linear functions provided the best fit for 80% and 20% of all species, respectively. All relationships were highly significant (P < 0.001, R 2 > 0.71) and the mean percent prediction errors were less than 10%. The results showed that reliable original size estimates of all species studied are obtainable from their otolith biometrics. The regressions from this study can be useful for investigators examining food habits of piscivorous fauna and sizes of these fishes in archaeological samples.

in order to determine the age, growth, and reproductive season. Fork lengths and weights of these samples varied between 11.5-24.3 cm and 22.80-259.00 g, respectively. Age estimates obtained from scales and vertebrae were compared to determine the most reliable bony structure for ageing. The precision analyses indicated that scales were the most appropriate hard structures for determining the age of white bream. Ages of all the specimens ranged from I to VI years and age group III was dominant. The parameters of the von Bertalanffy growth equations were calculated as L∞ = 32.85 cm, W∞ = 707.76 g, k = 0.11 year -1 and t0 = -2.64 year, and the growth performance index (Φ') value was computed as 2.074 for combined sexes. Fork length-weight relationship was found to be W = 0.0066 FL 3.317 . The mean condition factor was the highest in August and the lowest in October. The gonadosomatic index values showed that the reproduction occurred between May and June.Keywords: Ageing, scale, growth, reproduction season, Blicca bjoerkna, Lake Ladik Pul ve omurdan elde edilen yaşlar en güvenilir kemiksi yapının tespit edilmesi amacıyla karşılaştırılmıştır. Uyum analizleri Tahta Balığı'nın yaşının belirlenmesi için en uygun yapının pul olduğunu göstermiştir. Örneklerin yaşları I-VI arasında dağılım göstermiş ve III yaş grubu baskın yıl sınıfını oluşturmuştur. Populasyon genelinde von Bertalanffy büyüme denklemi parametreleri L∞ = 32,85 cm, W∞ = 707,76 g, k = 0,11 yıl -1 ve t0 = -2,64 yıl ve büyüme performans indeks değeri (Φ') 2,074 olarak hesaplanmıştır. Çatal boy-ağırlık ilişkisi W = 0,0066 ÇB 3,317 şeklinde elde edilmiştir. En yüksek ve en düşük ortalama kondisyon faktörü değerleri sırasıyla Ağustos ve Ekim aylarında elde edilmiştir. Gonadosomatik indeks değerleri üreme faaliyetinin Mayıs-Haziran aylarında gerçekleştiğini göstermiştir. RESEARCH ARTICLE

In this study, length-weight relationship (LWR), length-length relationship (LLR) and condition factor (K) of Angora loach, Oxynoemacheilus angorae were determined. A total of 103 specimens were sampled from Kılıçözü Stream in 2014. The length and weight of specimens were ranged 3.5-9.8 cm and 0.38-6.58 g, respectively. Lengthweight relationships for female, male and all samples were found as W= 0.01056.TL

In this study, some reproduction properties (sex ratio, reproduction period, egg diameter and fecundity) of Silurus glanis inhabiting Sıddıklı Reservoir were investigated. A total of 200 samples were caught between September 2015 and August 2016 from different regions of Sıddıklı Reservoir. Sex ratio was calculated as 0.88:1.00 (Female: Male). The sex ratio was not statistically different from the expected 1.00:1.00 (χ2= 0.841, P&gt;0.05). The values of gonadosomatic index (GSI) varied from 0.033 to 11.80 in females and 0.008 to 0.451 in males. According to GSI values, reproduction period of the S. glanis in Sıddıklı Reservoir was determined to be between April and June. The mean total fecundity and egg diameter were calculated as 46343 eggs/individual and 1.758 mm, respectively. Relative fecundity for each kilogram of female fish was 13000 eggs. The strong relationships between total fecundity-length and total fecundity-weight were determined (r2&gt;0.80).

Feeding habits and prey selection of European perch (Perca fluviatilis) were examined in Lake Ladik between November 2009 and October 2010. Stomach contents of 308 individuals ranging in size from 73 to 275 mm total length were analyzed and 55.2% were empty. The fullness index indicated that feeding intensity of this species was the highest in summer and the lowest in winter. European perch feeds on prey fish and macroinvertebrates. The most important food items were Scardinius erythrophthalmus and Perca fluviatilis, followed by chironomidae larvae. Diet composition and feeding habits varied seasonally and ontogenetically. Macroinvertebrates were only consumed by small individuals, while prey fishes were only eaten by large individuals. S. erythrophthalmus, P. fluviatilis, and Blicca bjoerkna were positively selected but their selection indexes were not statistically significant (p > 0.05). This prey selection is important for combating eutrophication. Abramis brama constitute 24.03% of all fish species in this lake; however, it was a negatively selected prey item (V a D ¡0.198, x 2 D 7.86, p < 0.05). Esox lucius, Squalius cephalus, Chondrostoma regium, and Carassius gibelio inhabiting this lake were not preferred by European perch. Cannibalism rate was 12.3%.