Hasan Acipinar

Interannual Variability of Fecundity and Egg Size of an Invasive Cyprinid, Carassius gibelio: Effects of Density-Dependent and Density-Independent Factors

ABSTRACT A population of the invasive Prussian carp (Carassius gibelio) was examined over a three-year period in a mesotrophic reservoir to find out interannual variations of fecundity and egg size and the influence of maternal condition (total length, TL, and age class) and environmental factors (water temperature and fish density) on these variables. Prussian carp reproduction was synchronous, with only a single batch, and fecundity ranged from 1,250 to 62,400 eggs per female. Relative fecundities and egg size showed no significant between-year differences. Fecundity increased with age, whereas egg diameter remained unchanged with age and TL. Fecundity was affected positively by TL and negatively by fish density, whereas temperature had no significant effect. Egg size was not affected by fish density or temperature.

Characteristics of a Eurasian cyprinid, Shemaya, Chalcalburnus chalcoides (Güldenstädt, 1772), in a mesotrophic water reservoir

Abstract Age, growth and reproduction of the Shemaya, Chalcalburnus chalcoides, was studied in the Ömerli Reservoir, a large drinking water system located in Istanbul province (Turkey). The von Bertalanffy growth function displayed variation in growth rates between the sexes. Asymptotic lengths calculated for both sexes were high, probably due to the lack of large predatory fishes and lack of fishing in the reservoir. Females dominated all age classes with the exception of the second age, and this phenomenon is characteristic of species from unstable and variable environments. The condition factor and the gonadosomatic index indicated that reproduction occurred around May-June. The estimated mean lengths at first maturity (L T50) were 14.83 cm and 15.98 cm for males and females, which corresponded to 1 and 2 years of age for both sexes. Natural mortality was 0.47/year. Fishing mortality as well as exploitation rate was negligible since fishing activity is prohibited throughout the year.

Threatened fishes of the world: Hemigrammocapoeta kemali Hankó, 1924 (Cyprinidae)

Common name: Cuce Siraz (Tr). Conservation status:Critically endangered CR B1ab (iii) (Crivelli 2006).Identification: DIII7–8, A II 5–6, P I 13, V I 7, Ll.scales 7–11, gill-rakers 13 –16, pharyngeal teeth 3.3.5–5.3.3, total vertebrae 30–31 (Geldiay and Balik 1996;Kucuk and Ikiz 2004). Body moderately deep (3.5–4.5in SL). Length 6–7cm(Balik 1995). Distribution: H.kemali is currently known only from Eregli marsh(southern Anatolia). The total marsh area is less than100 km