Liza saliens, Risso

Taxonomic description of species

Meristic features for the Caspian population (Kuliev, 1989): I D IV, II 7-8,A-III 8-9, squamae 42-52, vertebrae 23-25, pyloric caeca 8. Adipose eyelid rudimentary. Mouth small; gape does not reach posterior edge of preorbital. Top of head covered with scales almost up to anterior nostril. Lateral line on back and top of head has several canals (2-5). Color: 7-8 longitudinal stripes, grey-brown with golden reflection on sides.
Intraspecific forms. None
Related forms. Liza aurata (Risso, 1810) - singil, golden grey mullet. The Atlantic ocean from England to the South Africa, the Mediterranean and Black Seas.

Distribution of species within the Caspian Sea

Distributed throughout the Middle and South Caspian. Single specimens are found in the North Caspian. In winter concentrates mainly in the South Caspian.
Status as per International Red Data Book: N/A
Status as per National Red Data Books: N/A
First record for the Caspian Sea. Grey mullet (juvenile fish) was introduced from the Black Sea in 1930-1934. Svetovidov (1937) mentioned capturing grey mullet in the North Caspian in May, 1935. Commercial fishing at Turkmenian coastal areas was initiated in 1936.
Redescription of species. Liza aurata � Popov, 1930:64; Mugil saliens � Berg, 1949: 999

General characteristics of species

Ecologo-taxonomic group. Nekton
Origin. Mediterranean (introduced species, directed acclimatization)
World distribution. The Atlantic ocean from the Gironde estuary, the Mediterranean and Black Seas.
Habitat. During spawning period distributes in the pelagic zone of the Middle and South Caspian. Feeding on silt and organic remains takes place in warm shallow areas.
Migrations. Spawning - to the central part of the sea, feeding - to the coastal areas
Winters mostly in the South Caspian, in spring and summer migrates to the other areas up to the North Caspian.

Relation to abiotic environmental factors

Relation to salinity. Brackishwater marine species. Occurs at sea salinities ranging from 4⁰/₀₀ to 13⁰/₀₀ .
Relation to temperature. Thermophilic species. Migrates to the southern parts of the sea in autumn when the water temperature falls.
Vertical distribution. Keeps in the surface water layer above the depths 5-700 m.
Relation to oxygen conditions. Oxyphilic species
Relation to fluctuations of the sea level. The areas of shallow lagoons, where the young fish feed, might be reduced due to decline of the sea level .

Feeding

Feeding type. Heterotrophic
Feeding behavior. N/A
Food spectrum. Detritus, periphyton, small benthic organisms
Food supply. The food supply is not subjected to the seasonal and long-term fluctuations that ensures sustainable abundance of the population.
Quantitative characteristics of feeding. N/A

Reproduction

Reproduction type. Sexual
Reproduction areas. Spawning takes place in the open areas of the Middle and South Caspian above the depth of 700 m. In July �August 1970, the largest concentrations of eggs were found in the coastal waters of the South Caspian.
Terms of reproduction. Reproduces from the end of May at the temperature 22⁰C till the beginning of October. Batch spawning.
Fecundity. Fecundity ranges between 530 - 2,150 thousand eggs.
Limiting factors. Storms impact adversely on reproduction and development of eggs. Predation of other fish species on larvae and fry of grey mullet has impact on the rate of survival in the coastal areas; another factor is oil pollution of these regions.

Life history and development

Life-history stages. The eggs are pelagic, small (0.6�0.7 mm in diameter), with a big oil drop. Newly hatched prelarva (1.7 mm length) has the residual yolk sac. The fin fold is not differentiated. Only small oil drop remains in the larva of 4 mm length. The fry (11 mm TL) is densely pigmented; scales appear and the fins are formed.
Relation to environmental factors. N/A
Age of maturity. Males mature at the of three years, females � at four years.
Thermal conditions of development. Spawning and embryonic development occur at the temperature 22-29.4⁰C.
Quantitative characteristics of growth. The fry (11-13 mm TL, weight - 0.028-0.17 g) approach the western shores of the South Caspian in July (Probatov, Tereschenko, 1951). In the next year, at the end of June, they attain 61-95 mm length, weight � 3.4�12.6 g. The length increment estimated upon the data of reverse calculation (1978-1980), is higher in females compared with that of the males (Khoroshko, 1989)

Age-related length of leaping grey mullet, cm 

Structural and functional population characteristics

Sexual structure. In average, females account for 86% of the commercially exploited part of the population.
Age-size structure. Specimens aged from 2 to 8 years old occur in the catches; the majority is represented by the fish 24-30 cm TL, aged 2-5 years (Khoroshko, 1989). The maximum recorded size � 31.5 cm, maximum weight - 515 g (female aged 6+).
Quantitative characteristics. N/A
Population trends. N/A

Interspecific relations

The species is not a food competitor to any other species due to unique feeding habits(occupies separate food niche).

Importance of species to bioresources production of the Caspian Sea

Economic significance of species. Valuable commercial fish species
Commercial characteristics of species, catches. The catches of leaping grey mullet peaked in the period 1950-1960-s, further declined and correspond at present to 10 tons appr.
Fishing gears and fishing zones. Harvested with fixed nets, beach seines, and different traps (hoop nets, cover and matting ).

Impact of fisheries on the population status

None
Human impact/Threats. Oil pollution of the coastal areas can provide negative influence on leaping grey mullet at early developmental stages.
Conservation measures. Development of marine aquaculture

References

Adburakhmanov, Yu. A. 1962. Fish of freshwater bodies of Azerbaijan. Azerbaijan SSR AS Press. 407 p.
Adburakhmanov, Yu. A. 1966. Fish of freshwater bodies of Azerbaijan. Azerbaijan SSR AS Press. 224 p. (in Azerbaijaini).
Avanesov, E.M. 1972. The present conditions of golden grey mullet reproduction (the genus Mugil ) in the Caspian Sea . J. Voprosy Ikhtiologii (problems of Ichthyology). Vol.12, 3: 464-470
Badamshin, B.I. 1938. Golden grey mullet and its fry in the waters of the Mangyshlak Region. J. Fisheries 11: 37-38
Berg, L.S. 1949. Fish of the freshwater bodies of the USSR and adjacent states. Part 3 .USSR AS Press. Moscow-Leningrad pp 930-1382
Dubrovina, I.A. 1951.Mullet in the Northern Caspian and at the Kazakh coast of the Middle Caspian. VNIRO Proceedings. Vol. 18: 135-146
Khoroshko, A.I. 1989. Mullet. In : The Caspian Sea.Ichthyofauna and commercial stocks. Nauka Press. Moscow pp.178-184
Kudelina,, E.N. 1950. Mullet feeding in the Southern Caspian. Proceedings of VNIRO Caspian Branch. Vol. 11: 87-108
Kuliev, Z.M. 1989. Fish of the Kirov Bay of the Caspian Sea. ELM Publisher. Baku. 184 p.
Pertseva-Ostroumova, T.A. 1951. On the reproduction and development of mullet introduced ino the Caspian Sea .VNIRO Proceedings. Vol. 18.
Probatov, S.N. 1953. The results of the air exploring of the Caspian mullet and the possibilities of its catch on the routes of migration. Fisheries 8:18-22
Probatov, S.N. and Z.P. Tereshenko, 1951. Mullet in the Caspian Sea and its fishing. Pishchepromizdat. Moscow. 36 p.
Tereshenko, Z.P. 1950. Materials on biology and fishing of the Caspian mullet . Proceedings of VNIRO Caspian Branch. Vol. 11:49-86
Tomozo, G.I. 1940.Mullets (Mugilidae) in the north-eastern area of the Black Sea.-Proceedings of the Novor.Biol .Station. Vol. 2: 81-122 

Compiled by:

Kuliev Z.M. (AzerNIRKh, Baku, Azerbaijan),
Ragimov D.B. (Institute of Zoology Azerbaijani AS, Baku, Azerbaijan)