Biological Characteristics of a Rare and Vulnerable Species (SCHIZOTHORAX ARGENTATUS (Kessler, 1874)) of TOKYRAUYN RIVER and Approbation of Its Artificial Reproduction

Abstract

As a result of the complex impact of anthropogenic factors on the ecosystem of Balkhash Lake, the main commercial species of fish—endemic—Balkhash marinka was on the verge of extinction. Artificial reproduction is becoming increasingly important every year in the complex of works to maintain the commercial stocks of valuable fish species as well as to preserve rare and endangered populations. Despite the fact that attempts at artificial reproduction have been repeatedly made, to date no scientific and methodological basis has been created to study and preserve rare and endangered fish species in the Republic of Kazakhstan and there are no adapted technologies for the formation of repair herds of fish of this category for the fish breeding enterprises of the reproductive complex of Kazakhstan. The presence of a replacement stock of the Balkhash marinka will further contribute to the development and improvement of biotechnical methods for their breeding and cultivation of viable stocking material. The stocking of natural water bodies with viable fish seeds and the maintenance of living collections of rare and endangered fish species will contribute to their conservation in natural conditions and, as a reserve, in the country’s fish farms. The results of the development of effective technologies for artificial reproduction and the formation of a replacement stock of the Balkhash marinka in industrial conditions contribute to solving the fundamental problem associated with the preservation of rare and endemic fish species from complete extinction, genetic diversity and the rational use of the potential of natural populations. An analysis of genetic identification showed that the breeders of marinka, according to the results of sequencing the barcoding gene CO1 of mitochondrial DNA, belong to the species Balkhash marinka S. argentatus with an accuracy of 99–100%.

Current State of Rare and Endangered Barbels of the Genus Luciobarbus Heckel, 1843 in the Aral–Syrdarya Basin (Kazakhstan) and Prospects for Their Conservation (A Review)

“…However, what can be done to increase their numbers and thereby reduce the risk of complete extinction in the wild? A practical solution to this problem is possible only by removing the minimum required number of juveniles and spawners of rare species from their natural habitat, followed by artificial reproduction in fish farms of the Republic, for example, similar work is being carried out with the endemic Balkhash marinka [ 53 ].…”

“…For DNA extraction we applied the method from the previous work [ 53 ]. The amplification of cytochrome oxidase subunit 1 gene fragments was performed using the PCR technique.…”

Length-Weight-Age Relationship of Schizothorax eurystomus Kessler, 1872 and Comparison to Other Snow Trout Species in Central Asia

“…Notably, S. fedtschenkoi from the Zarafshan River exhibited a b-value slightly less than three [29], and the K value for S. intermedius from Tokyrauyn River was recorded at around 1.5, which is about 30% higher than the value observed in our study. However, it is important to mention that the latter study [30] did not provide other fish parameters or sample size details. Additionally, our literature review did not uncover any other studies addressing length-weight relationships and condition factors for Schizothorax species in Central Asia.…”

“…Additionally, a key distinction in age determination techniques exists between our study and previous research. While other studies relied on counting annual rings on scales [23,[30][31][32], our study employed operculum bones, offering a different approach to age assessment. Our results illustrated that S. eurystomus exhibits similar total lengths to other Schizothorax species during their first year.…”