Okan Yazıcıoğlu

Length-weight and length-length relationships of Capoeta sieboldii from Hirfanlı Dam Lake, Turkey.

ABSTRACT This study describes the length-weight (LWR) and length-length relationships of Capoeta sieboldii from Hirfanli Dam Lake, Turkey. Condition factor (K) was also calculated per fork length class of females and males. A total of 170 individuals was collected from monthly sampling between March 2004 and August 2005. LWRs of females and males were not statistically different with and within season. LWRs indicated isometric growth in both sexes. The slopes of LWRs were 3.171 for females and 2.980 for males. All correlations among fork length, total length, and standard length were highly significant (P>0.001, r2<0.92). The values of K ranged from 1.21 to 1.43 for females and from 1.12 to 1.36 for males.

Feeding ecology and prey selection of European perch, Perca fluviatilis inhabiting a eutrophic lake in northern Turkey

ABSTRACT 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 (Va = −0.198, χ2 = 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%.

Relationships Between Opercle Dimensions and Total Length of European Perch (Perca fluviatilis L., 1758) Inhabiting Lake Ladik (Samsun, Turkey)

There are so many researches about the effects of exercise on pulmonary Junctions. In some studies it were found that pulmonary function improved with exercise and in the others did not. It was generally accepted that there were improvement in pulmonary functions with swimming and diving. In this article the effects of exercise on pulmonary functions are reviewed. [Journal of Turgut Ozal Medical Center 1 (3):230-233,1994] Key words: Exercise, training, pulmonary functions, vital capacity.

BIOLOGICAL CHARACTERISTICS OF EUROPEAN PERCH (Perca fluviatilis L., 1758) INHABITING LAKE LADIK (SAMSUN, TURKEY)

Abstract The aim of this study was to determine the growth features of European perch (Perca fluviatilis L., 1758) inhabiting Lake Ladik. A total of 858 individuals were caught. The total length and weight ranged from 8.2 to 27.5 cm and from 7.16 to 365.20 g, respectively. The age of the females ranged between 1 and 7 years and the age of the males ranged from 1 to 5 years. The female to male ratio was 1:0.19. The von Bertalanffy growth equation parameters were determined as L∞=41.27 cm, W∞=1251.40 g, K=0.10 (year−1), t0 (year)=−1.98 for all samples. Length-weight relationship was calculated as W=0.0047TL3.358 for all specimens. Length-length relationships (total length-standard length, total length-fork length, standard length-fork length) were highly significant (r2>0.98). The mean condition factor value was obtained as 1.28 for all fish. Condition factor showed statistically significant increase according to length classes.

Ladik Gölü (Samsun, Türkiye)’ndeki kızılkanat balığı (Scardinius erythrophthalmus L., 1758) populasyonunda en güvenilir yaş tayini yönteminin belirlenmesi

Ages estimated from scales, vertebrae, opercles, utricular (lapillus) and lagenar (asteriscus) otoliths of 260 rudd (Scardinius erythrophthalmus L., 1758) specimens captured from Lake Ladik in February and March 2010 were compared to determine the most reliable ageing method. Three readings were made for each bony structure by one reader. Mean ages were determined for all bony structures and precision of ages obtained from multiple readings was evaluated calculating percent agreement (PA), average percent error (APE) and coefficient of variation (CV). Due to the highest PA (71.71 %) and the lowest APE (2.71 %) and CV (3.56 %) values, it was concluded that lapillus is the most reliable bony structure for age determination in Lake Ladik population of this species. When lapillus ages were compared with other bony structures, the highest precision was found between lapillus and asteriscus age readings.

Ladik Gölü (Samsun, Türkiye)’nde Yaşayan Tatlısu Levreği (Perca fluviatilis L., 1758)’nin Operkül Boyutları ile Balığın Total Boyu Arasındaki İlişkiler

There are so many researches about the effects of exercise on pulmonary Junctions. In some studies it were found that pulmonary function improved with exercise and in the others did not. It was generally accepted that there were improvement in pulmonary functions with swimming and diving. In this article the effects of exercise on pulmonary functions are reviewed. [Journal of Turgut Ozal Medical Center 1 (3):230-233,1994] Key words: Exercise, training, pulmonary functions, vital capacity.

The determination of the most reliable ageing method for the rudd (Scardinius erythrophthalmus L., 1758) population in Lake Ladik, Samsun, Turkey

Ages estimated from scales, vertebrae, opercles, utricular (lapillus) and lagenar (asteriscus) otoliths of 260 rudd (Scardinius erythrophthalmus L., 1758) specimens captured from Lake Ladik in February and March 2010 were compared to determine the most reliable ageing method. Three readings were made for each bony structure by one reader. Mean ages were determined for all bony structures and precision of ages obtained from multiple readings was evaluated calculating percent agreement (PA), average percent error (APE) and coefficient of variation (CV). Due to the highest PA (71.71 %) and the lowest APE (2.71 %) and CV (3.56 %) values, it was concluded that lapillus is the most reliable bony structure for age determination in Lake Ladik population of this species. When lapillus ages were compared with other bony structures, the highest precision was found between lapillus and asteriscus age readings.

population in Lake Ladik, Samsun, Turkey.

Ages estimated from scales, vertebrae, opercles, utricular (lapillus) and lagenar (asteriscus) otoliths of 260 rudd (Scardinius erythrophthalmus L., 1758) specimens captured from Lake Ladik in February and March 2010 were compared to determine the most reliable ageing method. Three readings were made for each bony structure by one reader. Mean ages were determined for all bony structures and precision of ages obtained from multiple readings was evaluated calculating percent agreement (PA), average percent error (APE) and coefficient of variation (CV). Due to the highest PA (71.71 %) and the lowest APE (2.71 %) and CV (3.56 %) values, it was concluded that lapillus is the most reliable bony structure for age determination in Lake Ladik population of this species. When lapillus ages were compared with other bony structures, the highest precision was found between lapillus and asteriscus age readings.