Issyk-Kul Marinka
Status: 2 [EN: D]. A rare taxon inhabiting Lake Issyk-Kul. Its independent species status was established in 1953 [10]. An endemic species with declining numbers, it has commercial significance.
Brief description of the adult form. Among all marinka species, it has the smallest scales that do not form regular rows. The dorsal spine is covered with small teeth for two-thirds of its length, whereas in other species it is entirely serrated.
General distribution and within the country. All coastal areas of Lake Issyk-Kul and the lower reaches of rivers flowing into it. It is more frequently found in northern areas than in southern ones. Tyup, Jergalan, and Pokrovsky Bays.
Habitat. In the lake, it is found in the most desalinated areas at the mouths of rivers. In warm weather, it is more commonly found in shallow zones at depths of 5-10 to 25 m, and in winter it migrates to depths of 40-60 m.
Population. It is generally rare. In the 1950s, the species accounted for about 3% of the total catch, but now it is caught only occasionally.
Life cycle (life habits). It does not form large schools [10]. It reaches sexual maturity at 4-5 years of age with a body length of 26-31 cm. Males mature a year earlier than females at a body length of 17-18 cm. The eggs are sticky, large, and toxic. Spawning begins in May and lasts until mid-July at water temperatures of +6...+8°C. In 80-90% of individuals, spawning is simultaneous, while in 10-20% it is in batches [5]; the incubation period lasts 6 days [5]. Eggs are laid on rocky beds or on the plates of "snags" near vegetation. Fecundity ranges from 1,200 to 93,000 eggs. It feeds on animal and plant food, with mollusks and stonewort predominating. Large individuals also include fish in their diet [10].
Limiting factors. Deterioration of conditions for natural reproduction, legal fishing and poaching, introduction of predatory fish species.
Breeding. It has been conducted [5].
Existing conservation measures. None have been taken.
Recommended conservation measures. Establishing a ban on commercial and amateur fishing, organizing artificial breeding. Identifying the causes of low population numbers and developing biotechnologies for artificial reproduction, establishing protected areas to conserve natural reproduction sites.
Black Carp Fish
Issyk-Kul Marinka
Schizothorax issykkuli (Berg, 1907)
Status: Category 2 [EN: D], rare endemic Issyk-Kul species with declining numbers, one of four congeners in the fauna of the country. The species is valuable for fishery. It populates all offshore waters in Issyk-Kul Lake but prefers northern shores, a usual inhabitant of desalinated zones in Tyup, Jergalan, and Pokrovsky Bays. It migrates in winter to deeper places 40-60 m down. It feeds on both animals and plants (mainly shellfish and stonewort); large individuals are also piscivorous. The spawning period is from May to mid-July; 10-20% of individuals spawn in stages. Fertility ranges from 1,200 to 93,000 eggs; the spawn is large, sticky, and toxic, laid on stony eminences. The population is insignificant; 50 years ago, the ratio of this species in the total catch was 3%, but now only single individuals have been registered. Limiting factors include legal fishing and poaching, deterioration of conditions for natural renewal, and the introduction of predatory fish species. There is experience in breeding this species in Kyrgyzstan. Currently, it is not under any protection. To conserve the species, it is necessary to prohibit amateur fishing and industrial fishery, organize breeding, protect sites of natural propagation, and continue studying the causes of its low abundance.
