Percarina maeotica
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| ( Kuznetsov , 1888) |
Azov Percarina ( Russian : перкарина Азовская, Azov-common percarina) is a freshwater and brackish water occurring bony fish from the family of Real perch (Percidae). It was described as a separate species in 1888, but is oftenviewedby various authors as only a subspecies of Percarina demidoffii .
features
Percarina maeotica differs little in body proportions and meristically (ie in quantitative characteristics) from Percarina demidoffii . In contrast to Percarina demidoffii , the head sides are scaled, which alone is not a sufficient reason to see a separate species in this population, which occurs in the area of the Sea of Azov . But there is also the darker color and biological differences.
The body is dark gray with numerous black dots that are closer to the back and can partly flow together, the belly is light. The fish is usually 5–6 cm long, the largest specimens are females aged three to four years of 10, 5 cm length. Males usually only reach the age of a little over two years, so only spawn twice.
Fin formula : D1 VIII – X, D2 II – III / 10–12, A II / 8–11.
Way of life and occurrence
Percarina maeotica is a bentho pelagic schooling fish that is not equally abundant everywhere in the Sea of Azov - it is extremely rare near the Don Estuary, but often at the Kuban Estuary. The fish spawns z. B. likes in the less brackish bay of Taganrog in early summer (with water temperatures around 24 ° C), like Percarina demidoffii over black mud, to which it is less bound in the diet, because it has more plankton and necton in the free water chases. The spawned eggs are very sticky, sink to the bottom and lie very loosely on the mud (so that they roll around with the slightest movement of water and "camouflage" themselves against predators with mud particles); The larvae (4 mm) hatched after two days are still there for about three days - before they rise to the surface and then, about 6 mm in length, copepods and the like. Start to eat plankton, later especially Mysida . This food can be seen in harmony with the dentition: According to Seeley (1886) the grater-like dentition of the lower jaw with several rows of pointed teeth is striking. Some of them also protrude outwards - it is reminiscent of that of the snipe eels , which also mainly eat long-legged and multi-legged shrimp (it is important that the "floating shrimp" get stuck on the lower jaw and not get along by tearing off individual, easily regenerable extremities their abdomen recoil from the dust ) - From the age of 1+ (over 4 cm long) they also eat young fish, such as Knipowitschia ( Gobiidae ) and Clupeonella ( Clupeidae ) - the mouth is relatively large. They also get worms, molluscs and insect larvae from the mud. Important predators are pikeperch and sticklebacks .
Danger
This species is also an important link in the food structure of the Black Sea Limane ecosystem . Human interference in the drainage of the southern Russian rivers, especially the Don , also potentially endangers their habitat (Kottelat and Freyhoff 2007), as it can hardly be found outside of the Azov Sea and the lower reaches of the tributaries. The IUCN currently classifies the species as widespread and not endangered ("Least Concern", LC).
Taxonomy
Percarina maeotica was initially described as a species in its own right, but then for a long time it was only regarded as a subspecies of Percarina demidoffii ( Percarina demidoffii maeotica Kuznetsov 1888). Lev S. Berg saw another species of his own in his 1949 work on the fish of the USSR . In her work from 2006, Yekaterina D. Wasiljewa rejects the distinction as artificial again due to an analysis of variations between the two species.
The type epithet refers to the palus Maeoticus , the "Maeotic pool", where Maiotis ( Greek : Μαιῶτις) also meant the area of today's Crimea .
literature
- Harry Govier Seeley: The fresh-water fishes of Europe, a history of their genera, species, structure, habits and distribution .- Cassell & Co., London 1886 ( Percarina demidoffii : pp. 31-32).
- ED Vasil'eva: Variation of the external characters and taxonomic relationships of Azov and Black-Sea populations of Percarina demidoffii (Percidae). In: Journal of Ichthyology. 46. 2006, 292-300 doi : 10.1134 / S0032945206040023
- M. Kottelat and J. Freyhof: Handbook of European freshwater fishes. Publications Kottelat, Cornol 2007
Individual evidence
- ↑ Percarina maeotica in the IUCN Red List of Threatened Species 2010.4. Posted by: Freyhof, J. & Kottelat, M., 2008. Retrieved December 10, 2010.
- ^ Lev S. Berg: Freshwater fishes of the USSR and adjacent countries. Volume 3, 4th edition, Israel Program for Scientific Translations Ltd., Jerusalem 1965 (English translation of the Russian version from 1949)
- ↑ ED Vasil'eva: Variation of the external characters and taxonomic relationships of Azov and Black-Sea populations of Percarina demidoffii (Percidae). Journal of Ichthyology, 46, pp. 292-300, 2006 doi : 10.1134 / S0032945206040023
Web links
- Percarina maeotica in Fauna Europaea
- Percarina maeotica on Fishbase.org (English)