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The present study deals with the fish fauna of Kurikotta Bridge Bennithora River, Gulbarga district of Karnataka. The study was undertaken for a period of one year and monthly collections were made from April-2013 to March-2014, in four sites. The result of present study reveals the occurrence of seventeen (17) fish species belonging to five orders. The order Cypriniformes was dominant with nine (9) followed by order Siluriformes (4) Channiformes (2), Mastacembelidae and Osteoglossiformes each with one species.
Background. The more than 10-metre deep archaeological site called the Vegetable Market (Kraut Markt), located near the Pomeranian Dukes’ Castle in Szczecin, was explored in 1953–1964. The site was found to contain 20 early-medieval sediment layers and a layer overlying the basement consisting of riverine mud. Historically, the layers spanned a period from the second decade of the 10th to the beginning of the 5th decade of the 13th century. Materials and Methods. The dig yielded numerous cultural artefacts, including fish remains examined during this study. The present paper summarises continuation of research on fish bone remains. The research allowed to identify a total of 10 085 bones in 725 labelled collections. The identified bones of 20 fish species were compared with bones of the extant known fish species, belonging to individuals of various size. The analysis made it possible to estimate the lowest abundance and weight of the fish present at the archaeological site examined. Results. The assemblage of 20 species, the remains of which were present in sediment of the site, turned out to be dominated, in terms of abundance, by carp bream (26.4%), followed by zander (17.5%), roach (15.9%), tench (9.5%), wels catfish (9.6%), northern pike (6.3%), European perch (6.0%), sturgeon (3.1%), and asp (2.2%), the total fish weight being dominated by sturgeon (31.3%), followed by wels catfish (27.0%), zander (15.3%), carp bream (10.6%), northern pike (5.1%), tench (4.2%), roach (2.2%), asp (2.1%), and European perch (1.1%). The remaining 11 species (twaite shad, European chub, ide, rudd, zope, white bream, Baltic vimba, ziege, crucian carp, European eel, and ruffe) contributed much less both to the abundance and to the weight.
Background. The topmouth gudgeon, Pseudorasbora parva (Temminck et Schlegel, 1846) (known also as stone moroko), is an alien species of the fish fauna of many European freshwater ecosystems. In large quantities, its may affect negatively the fish fauna and the functioning of ecosystems. It competes for food with native fish species and they occupy their habitat. The knowledge about the invasion dynamics may help to find suitable control measures. The aim of this study was to find and observe the population of P. parva in a small river. Materials and methods. Inventory fishing on three sampling sites at the Ciemięga River was carried out from 2003 to 2007. The abundance and density of P. parva in the river were calculated. The size distribution of P. parva and its length–weight relation were determined. Abundance, density, length, and mass of the fish from all study sites were analyzed statistically. Results. P. parva was first recorded in the Ciemięga River in the autumn of 2005. The abundance of P. parva in relation to the structure of the local ichthyofauna was the smallest in the spring and the highest in autumn. The total length of P. parva ranged from 15 to 104 mm, and the mass from 0.2 to 10.4 g. Taking into account the number of the specimens, P. parva constituted between 0.9% and 57.2% of the local ichthyofauna, while its mass ranged from 0.0% to 35.1% depending on the study site and the season. The density of P. parva ranged from 72.9 to 6.5 CPUEn, while the mean value for the river was 30.6 CPUEn. Conclusion. In Polish waters P. parva is an alien species and there is still little information about its occurrence in the flowing waters. Since 2005, this species was present almost in all inventory catches in the Ciemięga River. Its presence was dependent on the kind of the habitat and the presence of predatory fish species (eg brown trout). P. parva occurring numerous may be a lot of competition for native fish species, and therefore an important problem is to understand his habitat preferences and interactions with native fish species.
To assess the current ecosystem status of Montedoglio Reservoir and surrounding waters, the fish fauna has been analysed in 1993, about five years after the first experimental impoundment. Total number of 898 fishes of fifteen species have been collected of the total biomass of 117 kg. The most abundant species were pumpkinseed (Lepomis gibbosus), goldfish (Carassius auratus L.), bleak (Alburnus alburnus alborella De Fil.), largemouth bass (Micropterus salmoides Lac.), rudd (Scardinius erythrophthalmus L.), and chub (Leuciscus cephalus L.), while the three: Carp (Cyprinus carpio L.), goldfish, and largemouth bass accounted for the most biomass. Of the most common species, carp, chub, largemouth bass and rudd provided insight into population structure and growth. In 1992, a year of heavy spring rains and a rapid water exchange, a year-class abundance across all species was particularly poor. The results of water levels and outflows between 1992-1994 showed a high degree of instability of the system. It appeared to favour fish species depositing their eggs inshore (i.e. chub) and predators (i.e. largemouth bass), while species with life stages feeding on plankton or benthos were not favoured.
Existing data on Wałecki barbel are very scarce and need a complement to the quantitative description of its habitat conditions. This fish is a subspecies of the Pontic species B. cyclolepis Heckel which occurs in some coastal rivers of the Black Sea or, as evidenced by some results of studies on mitochondrial DNA, it is a hybrid originating from natural crossing between the common barbel Barbus barbus (L.) and spotted barbel B. carpathicus Kotlík, Tsigenopoulos, Ráb et Berrebi. Until now the Wałecki barbel was reported from 26 sites in the river basins of the Upper Vistula and the Dniester in SE Poland (49°09’–49°49’N, 21°28’–22°50’E, altitude 200–590 m). Seventeen of these sites were studied in autumn 2002 and summer 2003 to collect data on habitat parameters of stream channels. The main characteristics of their morphology (i.e. length, width, depth, and gradient) were calculated on the basis of a set of field measurements. Current velocity was measured using float method. The composition of bottom substratum was estimated using a simple scale based on Wentworth scale. Additionally, two biotic characters were included, i.e. the occurrence of macroscopic aquatic vegetation and the species composition of fish community. According to the obtained results the habitat conditions appropriate for Wałecki barbel may be defined as follows: 1) The stream should be medium-sized, at least 10-m or better 20-m wide. 2) The mean channel depth should exceed 20 cm, while the maximum depth should be greater than 50 cm. The channel morphology with the zone of medium depth (i.e. that extending over the half of bottom) in range between at least 15 and 40 cm seems to be favorable. 3) The mean stream velocity of 0.30 m s⁻¹ or more is desired. It seems that the zone of fast current (0.50– 1.00 m s⁻¹) sharing a considerable portion of the channel is an important habitat feature. 4) Most of the bottom area should be covered by mediumsized particles (2–200 mm) with the mode within range of fine pebbles (20–50 mm). 5) In general, the stream should be rather oligotrophic than eutrophic with poorly developed macroscopic algae and the absence of vascular plants, and with flow fluctuations periodically disturbing structure of bottom substratum. 6) The abundant occurrence of spotted barbel, especially within lower part of its distribution area and in the zone of its co-occurrence with common barbel may be regarded as a good indicator of the stream habitat appropriate for Wałecki barbel. 7) Other frequent and abundant species accompanying Wałecki barbel are minnow Phoxinus phoxinus (L.), stone loach Barbatula barbatula (L.), chub Leuciscus cephalus (L.) and schneider Alburnoides bipunctatus (Bloch).
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