Zingel zingel

Abstract: A total of 10 649 larval and juvenile fishes of 24 species were caught in the drift at Marchfeldkanal, a man-made side branch of the Danube River near Vienna, Austria, with tubenose goby Proterorhinus marmoratus being the dominant species. Distinct differences in inter- and intraspecific drift patterns among different sampling stations along the course of the channel were found. The percentage of the rheophilic and rheoparous ecological guild was highest at the inlet of the channel, where it is directly fed with water from the Danube. For individual species, significant differences in drift densities among sites were found for tubenose goby, barbel Barbus barbus, ide Leuciscus idus, roach Rutilus rutilus and for the two most abundant percids, the pike-perch Sander lucioperca and zingel Zingel zingel combined. The occurrence of larval and juvenile fishes in the drift was related to certain developmental stages and differed between species and sites. Most species (common bream Abramis brama, bleak Alburnus alburnus, gudgeon species Gobio spp., chub Leuciscus cephalus, ide and roach) occurred with highest densities at the earliest developmental larval stage, but some species (e.g. common bream and roach) were also found abundantly in drift at later developmental stages. Application of Ivlev‘s index of electivity as a drift index describing the propensity of the different species to drift, yielded the highest indices for the gudgeon species, common bream and bleak and the lowest for perch Perca fluviatilis, Prussian carp Carassius auratus gibelio and rudd Scardinius erythrophthalmus.

Abstract: SUMMARYKaryotypes of eight species of European percid fishes representing all European tribes of Percidae, viz. Percini (Perca fluviatilis, Gymnocephalus cernuus, G. baloni, G. schraetser), Luciopercini (Stizostedion lucioperca, S. volgense) and Romanichthyini (Zingel zingel, Z. streber) were analyzed. Diploid chromosome numbers 2n = 48 have been found in all species analyzed. Their karyotypes are dominated by submetacentric to subtelocentric and acrocentric chromosome and differ in number of metacentric elements: one pair P. fluviatilis, S. lucioperca, S. volgense and G. cernuus to 5 pairs in G. baloni and G. schraetser. In the karyotypes of all species analyzed, the same marker chromosome pairs have been detected, viz. a pair of small metacentrics and a pair of large satellited (i.e. NORs carrying) subtelocentrics, respectively. Karyology of Percidae is further reviewed and discussed. It is postulated that chromosomal evolution of the family has been connected with rearrangements changing the centromere...

Abstract: The lower Morava and Dyje rivers belong among the large lowland rivers on the southeast of the Czech Republic flowing into the Danube 69 km downstream of their confluence. Despite their high nature value and environment protection, both rivers suffered from heavy pollution from the sixties to the eighties of the last century. Significant improvement of their water quality during the last two decades resulted in the partial recovery of former assemblages of both benthic macroinvertebrates and fish. Recently, altogether 262 and 137 taxa of macrozoobenthos were recorded at the Dyje and Morava rivers, respectively. In the River Dyje, 3 and 21 non-native and threatened (according to IUCN categories) invertebrate species, respectively, were ascertained, whilst in the River Morava their numbers were 2 and 10, respectively. The fish assemblage consisted of 23 and 24 species, respectively, plus one hybrid in each of the rivers, bleak being by far the most abundant fish. In the sections under study, several rare and/or protected species were also recorded. Two of them, ide (Leuciscus idus) and burbot (Lota lota) belong among vulnerable fish species and four others, white-eye bream (Abramis sapa), striped ruffe (Gymnocephalus schraetser), streber (Zingel streber) and zingel (Zingel zingel), are considered as critically endangered species. Currently, both lower stretches of the rivers Morava and Dyje have been heavily invaded by round goby, Neogobius melanostomus.

Abstract: Ecological monitoring from water of the River Danube and Srebarna Lake was performed using freshwater fishes and their parasites and parasite communities as bioindicators. For an ecological evaluation of the situation of the analyzed freshwater ecosystems, principal biotic indexes were fixed. The analysis of the dominant structure of the found taxa was presented to the level of the component communities. During 2012, 16 species and 181 specimens of freshwater and passage fish were examined with standard techniques for parasites. Six species of examined fish (Aspius aspius (L., 1758) , Carassius gibelio (Bloch, 1782), Chondrostoma nasus (L., 1758), Zingel zingel (L., 1758), Cyprinus carpio (L., 1758) and Lepomis gibbosus (L., 1758) ) were free of parasites. In ten species of fish (Abramis brama (L., 1758), Alburnus alburnus (L., 1758), Alosa pontica (Eichwald, 1838), Ballerus sapa (Pallas, 1811), Barbus barbus (L., 1758), Romanogobio albipinnatus (Lukasch, 1933), Gymnocephalus schraetser (L., 1758), Neogobius fluviatilis Pallas, 1811, Perca fluviatilis L., 1758, Rutilus rutilus (L., 1758)) seven species of parasites (Gyrodactylus elegans Nordmann, 1832, Diplozoon paradoxum Nordmann, 1832, Nicolla skrjabini (Iwanitzky, 1972), Pomphorhynchus tereticollis (Rudilphi, 1809), Eustrongylides excisus (Jgerskild, 1909) larvae, Hysterothylacium aduncum (Rudolphi, 1802), Camallanus truncatus (Rudophi, 1814)) were fixed. New parasite and host records were determined. All fixed parasite species are core for the parasite communities of examined fishes with the exception of N. skrjabini. Bioindicator significance of parasite species was studied.