Azov percarina
Percarina maeotica (Russian: Азовская перкарина, Azov- Perkarina ) is occurring in freshwater and brackish water fish bone from the family of the Real perch ( Percidae ). He was described in 1888 as a separate species, but is often viewed by various authors only as a subspecies of Percarina demidoffii.
Features
Percarina maeotica differs in the body proportions and meristisch (ie quantitative) little of Percarina demidoffii. The sides of the head, in contrast to Percarina demidoffii beschuppt, what else alone is not a sufficient reason in this population, which occurs in the area of the Azov Sea, its own way of seeing. For this purpose, but come the darker color and biological differences.
The hull is dark gray, with numerous black dots, which are at the back denser and can coalesce in part, the belly is bright The fish is usually 5-6 cm long, the largest specimens are females between the ages of three to four years from 10 5 cm in length. Males usually reach only the age of a little over two years, so only spawn twice.
Fins formula: D1 VIII -X, D2 II-III/10-12, A II/8-11.
Lifestyle and deposits
Percarina maeotica is a benthopelagic fish swarm, which is often not the same everywhere in the Azov Sea - near the Don Estuary it is extremely rare, often, however, on the Kuban estuary. The fish spawns, for example, like in the little brackish bay of Taganrog in the early summer (when water temperatures around 24 ° C), namely as Percarina demidoffii over black mud, to which it is in the diet but less bound, as he hunts more in open water plankton and nekton. The abgelaichten eggs are very sticky, sink to the bottom and are quite loose on the mud ( so they roll around at the slightest water movement and can "camouflage " with mud particles against predators ); the hatched larvae after two days (4 mm) are currently about three days - before they rise to the surface and then, with about 6 mm in length, copepods to eat and the like plankton begin later especially Mysida. This food can be with the dentition in accordance see: According to Seeley (1886 ) reibeisenartige the dentition of the lower jaw is striking with several rows of pointed teeth, which in some cases also project to the outside - it reminds hereby to which the Schnepfenaale which also mainly eat all the days and vielbeinige shrimp ( it is important that the " floating shrimp " stuck on the lower jaw and not by tearing of individual, easily regenerable limbs with her abdomen recoil from the dust make ) -. from age 1 ( about 4 cm long) they also eat young fish, such Knipowitschia ( Gobiidae ) and Clupeonella ( Clupeidae ) - the mouth is indeed relatively large. From the mud they get next to worms, molluscs and insect larvae -. Important predators are walleye and Sichlinge.
Endangering
This species is an important link in the food web of the ecosystem of the Black Sea Limane. By human intervention in the runoff of the southern Russian currents, particularly the Don, is also their habitat potentially endangered ( Kottelat and Freyhoff 2007), since it is hard to find outside of the Azov Sea and the lower courses of the feeder. The IUCN classified the species present, however, as widespread and as not at risk ( "Least Concern", LC) a.
Taxonomy
Percarina maeotica was initially described as a distinct species, but then long regarded merely as a subspecies of Percarina demidoffii ( Percarina demidoffii maeotica Kuznetsov 1888). Lev S. Berg looked in his 1949 published work on the fishes of the USSR again own Art Ekaterina D. Wasiljewa rejects the distinction from again as artificial due to variation analysis of the two species in their work from the year 2006.
The specific epithet refers to the palus Maeoticus, the " maiotischen cesspool " where Maiotis (Greek: Μαιῶτις ) also meant the area of today's Crimea.