AGE AND GROWTH OF THE SILVER CARP (Hypophthalmichthys molitrix Val.) IN TUDAKUL RESERVOIR, UZBEKISTAN

Abstract

A study was carried out from November 2010 to October 2011 in Tudakul reservoir, Uzbekistan. A total of 142 silver carps, Hypophthalmichthys molitrix Val., were sampled including 65 females and 77 males. The scale of silver carp is cycloid with straight edges. Annulus on scale of immature silver carp appears in March and of matured fish during the spawning period in the second half of May. The ages, total lengths and weights of the samples ranged between 1 to 5 years, 15 to 105 cm and 35 to 17,500 g, respectively.The relation between the total length (TL) and weight (W) was described by equation W = 0.0065xTL 3.1572 (r=0.99). The relationship between the total length (TL) and the standard length (l) was described by a linear equation: l = 0.8973xTL -1.571 (r = 0.99). The mean estimated total length of 1-yearold silver carp was 25.25 cm; 2-year-old, 49.81 cm; 3-year-old, 68.91 cm; 4-year-old, 89.94 cm; 5-year-old, 94.47 cm. The mean back calculated total length was 28.2 cm at age I; 56.2 cm, II; 71.18 cm, III; 89.56 cm, IV; 98.9 cm, V. R. Lee's phenomenon was not manifested as the fishing company is oriented to the catches of large fish.

Factors limiting successful reproduction in wild silver carp, Hypophthalmichtys molitrix, in Kherrata Reservoir, Algeria

“…14), which corresponded to maximum vitellogenin and estrogen synthesis and the onset of the spawning season (Lenhardt and Cakiae 2002). In the natural environment of this species, the diameter of the ripe eggs before spawning was 0.6-1.01 mm in Uzbekistan (Kamilov and Komrakova 1999) and 0.5-1.7 mm in Syr Darya in Kyrgyzstan (Abdullayev and Khakberdiyev 1989), while in the present study the maximum value was 1.4 mm noted in stage V.…”

“…It is known that GSI increases concomitantly with gonad maturation, and it reaches maximum values at the onset of the breeding period and decreases abruptly as soon as the breeding period is over (Roy and Mandal 2015). The GSI of the mature females before ovulation ranged from 9.1 to 37.2% in Uzbekistan (Kamilov and Komrakova 1999), 4.14 to 17.7% in the Balkhash-Ili basin in Kazakhstan (Karpov et al 1989), and from 5 to Factors limiting successful reproduction in wild silver carp, Hypophthalmichtys molitrix... 165 29.7% in Syr Darya River in Kyrgyzstan (Kamilov and Salikhov 1996). Temperature is regarded as the main determinant factor in reproduction in the cyprinid family (Billard et al 1978, Billard 1995.…”

Ecological state of Tudakul reservoir in Uzbekistan and estimation of fish capture in last decades

“…Hydroconstruction and regulation of river flows, construction of irrigation canals, carried out since the middle of the last century, destroyed the isolating barriers for aquatic organisms and connected all the main river basins of the Amu Darya, Zarafshan, Kashkadarya, Syrdarya and others [1,[5][6][7][8]. All these factors led to the mixing of fauna and the independent dispersal of a large number of aquatic organisms.…”

“…In subsequent publications, it is reported about the penetration of 4 more fish species through the ABMC. Thus, based on the analysis of literary sources, the list of fish that lived in the Tudakul reservoir by the end of the 20th century included 30 species [5].…”

Comparative Study of Bacterial Flora in Intestinal Contents of Wild and Farmed Hypophthalamichthys molitrix Through High-Throughput Sequencing

“…Silver Carp (Family: Cyprinidae) is a very common fish at global level and considered to be the best for stocking and aquaculture. It is regarded to be the most important and appropriate specie of cultured fish globally (Kamilov et al, 2014). In Pakistan the Silver Carp is the most dominant fish in freshwater biomes of the Punjab and other provinces because of their appropriate reproductive potential and easy feeding (Khan et al, 2011).…”