The first record of black bullhead Ameiurus melas (Pisces, Ictaluridae) in Serbian waters

On the 14th of June, 2005, in the Danube side channel "Jojkić" (N 44°50'33.1’’, E 20°27'46.1’’) near Belgrade, we recorded the presence of A. melas, ranging in weight (W) from 11.2 g to 135.6 g, and standard length (Ls) from 70 mm to 173 mm. Specimens were obtained from professional fishermen, who caught them with gill nets, as well from sport fishermen using fishing roads. Also, on 28th of May, 2005, on the lake "Savsko jezero" (N 44°47'20.1’’, E 20°24'54.6’’), we collected two specimens with gill nets. They were held in an aquarium until the 20th of June, when they were analyzed. Their weight (W) was 48.8 g and 97.5 g, their standard length (Ls) 145 mm and 183 mm, respectively.nul

The first record of black bullhead Ameiurus melas (Pisces, Ictaluridae) in Serbian waters

On the 14th of June, 2005, in the Danube side channel "Jojkić" (N 44°50'33.1’’, E 20°27'46.1’’) near Belgrade, we recorded the presence of A. melas, ranging in weight (W) from 11.2 g to 135.6 g, and standard length (Ls) from 70 mm to 173 mm. Specimens were obtained from professional fishermen, who caught them with gill nets, as well from sport fishermen using fishing roads. Also, on 28th of May, 2005, on the lake "Savsko jezero" (N 44°47'20.1’’, E 20°24'54.6’’), we collected two specimens with gill nets. They were held in an aquarium until the 20th of June, when they were analyzed. Their weight (W) was 48.8 g and 97.5 g, their standard length (Ls) 145 mm and 183 mm, respectively.nul

First record of the North American paddlefish (Polyodon spathula walbaum, 1792) in the Serbian part of the Danube river

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Occurence of Anguillicola crassus, ematoda: Dracunculoidea, in eels of lake Ohrid, Macedonia

The first record of the eel parasite Anguillicola crassus Kuwahara (Niimietltagaki, 1974) from Lake Ohrid and the Republic of Macedonia is reported here. Parasitological examinations comprised 68 specimens of the eel Anguilla anguilla Linnaeus, 1758 of which 39.71% were infected with Anguillicola crassus. The prevalence varied depending on the season, with the highest value occuring during the autumn (47.06%). Average intensity of infection was 10.33. Anguillicola crassus was probably introduced into the lake by the artificial stocking with eel young, imported from abroad. It has found convenient conditions for development and multiplication in the lake due to the presence of transitional and paratenic hosts.U periodu od aprila 1995. do marta 1996. godine, na makedonskom delu Ohridskog jezera, parazitološkompretragomobuhvaćenoje68primerakajegulja (Anguilla anguilla Linnaeus, 1758), od kojih je 27 bilo inficirano nematodom Anguillicola crassus (ekstenzitet infekcije je iznosio 39,71%). Ekstenzitet infekcije je varirap u zavisnosti od sezone. Najveći je bio u toku jeseni. Intenzitet infekcije je iznosio između 1-90, a prosecan intenzitet infekcije je iznosio 10,33. Anguillicola crassus je najverovatnije uneta u jezero veštačkim poribljavanjem podmlatkom jegulja, uvezenim iz inostranstva. U jezeru je ovaj parazit našao povoljne uslove za razvoj i razmnožavanje prisustvo prelaznih i parateničnih domaćina. Anguillicola crassus je po prvi put spomenuta u ihtioparazitofauni Ohridskog jezera i Makedonije.nul

Influence of the twilight period and different sampling methods on catch of Gobiids (Gobiidae) at four locations in the inshore parts of the Danube River

The aim of this work was to compare the efficiency of two different methods for fish sampling and to assess the influence of the twilight period on the catch of gobiids along the Danube River in Serbia. The samplings were performed by electrofishing and beach seining in inshore parts of the Danube River with water depth up to 120 cm at four locations: Novi Sad, Belgrade, Tekija, and Prahovo, in October 2012 and September 2013. At each location, the samplings were performed at 17:30, 18:30, 19:30 and 20:30. Totally, 539 gobiids were caught. The highest number of specimens (218) was registered at Tekija, while lower numbers were registered at Belgrade (192) and Prahovo (117), and only 12 specimens were caught at Novi Sad. The catch of the round goby Neogobius melanostomus and monkey goby Neogobius fluviatilis was more efficient by beach seining than by electrofishing, whereas the catch of the tubenose goby Proterorhinus semilunaris was more efficient by electrofishing. Both methods had similar efficiency in catching the bighead goby Ponticola kessleri and racer goby Babka gymnotrachelus. The species diversity and number of the caught specimens were the highest at 18:30. All five species were recorded at Belgrade, Tekija and Prahovo, while only the monkey goby and racer goby were caught at Novi Sad. The methods used in this study showed good efficiency in catching gobiids, especially at dusk. Even though these methods are difficult to apply in certain habitats, they could be highly relevant in the regular monitoring of gobiids along the inshore parts of rivers

Influence of the twilight period and different sampling methods on catch of Gobiids (Gobiidae) at four locations in the inshore parts of the Danube River

The aim of this work was to compare the efficiency of two different methods for fish sampling and to assess the influence of the twilight period on the catch of gobiids along the Danube River in Serbia. The samplings were performed by electrofishing and beach seining in inshore parts of the Danube River with water depth up to 120 cm at four locations: Novi Sad, Belgrade, Tekija, and Prahovo, in October 2012 and September 2013. At each location, the samplings were performed at 17:30, 18:30, 19:30 and 20:30. Totally, 539 gobiids were caught. The highest number of specimens (218) was registered at Tekija, while lower numbers were registered at Belgrade (192) and Prahovo (117), and only 12 specimens were caught at Novi Sad. The catch of the round goby Neogobius melanostomus and monkey goby Neogobius fluviatilis was more efficient by beach seining than by electrofishing, whereas the catch of the tubenose goby Proterorhinus semilunaris was more efficient by electrofishing. Both methods had similar efficiency in catching the bighead goby Ponticola kessleri and racer goby Babka gymnotrachelus. The species diversity and number of the caught specimens were the highest at 18:30. All five species were recorded at Belgrade, Tekija and Prahovo, while only the monkey goby and racer goby were caught at Novi Sad. The methods used in this study showed good efficiency in catching gobiids, especially at dusk. Even though these methods are difficult to apply in certain habitats, they could be highly relevant in the regular monitoring of gobiids along the inshore parts of rivers

First record of the North American paddlefish (Polyodon spathula walbaum, 1792) in the Serbian part of the Danube river

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Age, growth, sexual maturity and diet of the Mediterranean barbel (Barbus peloponnesius petenyi) in the River Gradac (West Serbia, Yugoslavia)

Mediterranean barbel Barbus peloponnesius petenyi from the River Gradac were studied during the period September 1985 - July 1993 with the aim to determine their growth and feeding habits. The age estimated from scales ranged from 1+ to 7+. In older age classes (5+, 6+ and 7+), only sexually mature females were caught. The length-weight relationship is expressed by the equation log W = -1.947 + 3.004 . log L. Relative condition factor was higher during August than during May and November. Males attain sexual maturity in their 2nd and 3rd year of life, whereas females in their 3rd and 4th year. The diet of Mediterranean barbel consists mainly of insect larvae and some Gastropoda and Amphipoda. The most numerous were Chironomidae and Simuliidae. Mediterranean barbel grow well in the River Gradac, which is a consequence of the favourable feeding conditions in this unpolluted ecosystem.nul

Age, growth, sexual maturity and diet of the Mediterranean barbel (Barbus peloponnesius petenyi) in the River Gradac (West Serbia, Yugoslavia)

Mediterranean barbel Barbus peloponnesius petenyi from the River Gradac were studied during the period September 1985 - July 1993 with the aim to determine their growth and feeding habits. The age estimated from scales ranged from 1+ to 7+. In older age classes (5+, 6+ and 7+), only sexually mature females were caught. The length-weight relationship is expressed by the equation log W = -1.947 + 3.004 . log L. Relative condition factor was higher during August than during May and November. Males attain sexual maturity in their 2nd and 3rd year of life, whereas females in their 3rd and 4th year. The diet of Mediterranean barbel consists mainly of insect larvae and some Gastropoda and Amphipoda. The most numerous were Chironomidae and Simuliidae. Mediterranean barbel grow well in the River Gradac, which is a consequence of the favourable feeding conditions in this unpolluted ecosystem.nul