Parasites of Apollonia melanostoma (Pallas 1814) and Neogobius kessleri (Guenther 1861) (Osteichthyes, Gobiidae) from the Danube River in Austria

2009 ◽  
Vol 84 (1) ◽  
pp. 87-92 ◽  
Author(s):  
J.M. Mühlegger ◽  
F. Jirsa ◽  
R. Konecny ◽  
C. Frank
Keyword(s):  
Round Goby ◽  
Body Cavity ◽  
Parasite Fauna ◽  
Neogobius Melanostomus ◽  
The Body ◽  
Danube River ◽  
The Danube River ◽  
Acanthocephalus Lucii ◽  
Apollonia Melanostoma ◽  
Low Prevalence

AbstractTwo invasive fish species, the round goby Apollonia melanostoma syn. Neogobius melanostomus (Pallas 1814) and the bighead goby Neogobius kessleri (Günther, 1861), have established a firm population in Austrian waters during the past 15 years. As there have been no records of the parasite fauna from these populations, a total of 79 specimens of A. melanostoma and 12 specimens of N. kessleri were examined for parasites between May and October 2007 from three different sampling sites from the Danube River in Austria. In total 12 parasite taxa were recovered. The protozoans Trichodina sp. and Ichthyophthirius multifiliis from the gills and skin; two crustacean species, Paraergasilus brevidigitus and Ergasilus sieboldi, from the gills; and the two monogeneans Gyrodactylus sp. and Dactylogyrus sp., from the skin and gills respectively, all occurred at low prevalence and intensities. Furthermore, cystacanths of the acanthocephalan Acanthocephalus lucii were found in the body cavity. Metacercariae of the digeneans Diplostomum sp. and Tylodelphys clavata were found in the lens of the eye and the vitreous humour, respectively. Adults of two digeneans, Nicolla skrjabini and Bunodera nodulosa, were found in the intestine. In addition, during this survey metacercariae of the Holarctic digenean Bucephalus polymorphus, encysted in the skin and fins, with prevalence up to 78%, were recorded for the first time in Austria.

scholarly journals Feeding activity and diet composition of round goby (Neogobius melanostomus, Pallas 1814) in the coastal waters of SE Baltic Sea

2015 ◽  
Vol 44 (4) ◽  
Author(s):  
Artūras Skabeikis ◽  
Jūratė Lesutienė
Keyword(s):  
Baltic Sea ◽  
Coastal Waters ◽  
Diet Composition ◽  
Feeding Activity ◽  
Macoma Balthica ◽  
Round Goby ◽  
Benthic Fauna ◽  
Neogobius Melanostomus ◽  
The Body ◽  
Gut Contents

AbstractFeeding activity and diet composition of round goby were investigated in the south-eastern Baltic Sea, the Lithuanian coastal waters during May-October 2012 in order to determine main feeding objects and seasonal periods when native fauna could be most affected by predation of this highly invasive species. In total, prey represented by 18 taxa was found in the gut contents of dissected fish. Feeding activity of round goby varied depending on the body size, sex and stage of the reproduction period. The gut contents of < 50 mm specimens were dominated by zooplanktonic and meiobenthic organisms, whereas larger individuals (50–99 mm) shifted to amphipods and mollusks. Individuals of the intermediate 100-200 mm length had a variable diet, changing depending on the season; in spring they mostly preyed on Macoma balthica, in summer − on polychaetes, while in autumn the contribution of Mytilus trossulus and fish considerably increased in their diet. Diet composition of individuals ≥ 200 mm was relatively constant in the course of the study with substantial preference to M. balthica. These findings imply that benthic fauna, particularly a newly settled generation of epibenthic mollusks in autumn is under strong predatory pressure of the round goby.

scholarly journals An Investigation into the Health Risks Associated with the Noise and Vibrations on Board of a Boat—A Case Study on the Danube River

2019 ◽  
Vol 7 (8) ◽  
pp. 258
Author(s):  
Picu ◽  
Picu ◽  
Rusu
Keyword(s):  
Blood Pressure ◽  
Body Temperature ◽  
Work Capacity ◽  
Sound Level ◽  
The Body ◽  
Danube River ◽  
Maximum Efficiency ◽  
Low Level ◽  
The Danube River ◽  
Research Findings

This paper studies the noise and vibrations transmitted to the crew of a pusher with eight barges sailing upstream the Danube River, between Cernavoda and Drobeta, with a staff consisting of a captain, one coxswain, one mechanic and three sailors. The research was conducted over a one-week period in August 2018. The navigation time was 24/24 h and the seafarers’ schedule was 4/8. Determinations were made on three different workers: Coxswain, mechanic and sailor. The meteorological parameters and the Danube river levels, the sound level and the transmitted vibrations, as well as the body temperature and blood pressure of the subjects were measured. The periods of activity and sleep were analyzed by means of an actigraph. Our research findings indicate that people worked overtime, slept less than necessary and, generally, did not observe the official program. The noise (LEP,d = 92 dB) and vibration levels (a total exposure A(8) = 4.1 m/s2) also contributed to the sleep disorder. Such effects were accompanied by increased body temperature and blood pressure. Synthesizing, it can be concluded that: The peak (acrophase) of the work capacity was from 9:00 to 11:00 and from 17:00 to 19:00, which represent the maximum efficiency periods. More specifically, the highest mental performances were recorded in the morning, while the maximum physical ones were to be seen in the afternoon. The minimum efficiency period was from 13:00 to 15:00. Decreases in the work capacity were identified at 23:00 (reasonably low level) and 3:00 (extremely low level).

scholarly journals 2D vs. 3D Numerical Approaches for Fish Habitat Evaluation of a Large River — Is 2D Modeling Sufficient?

2021 ◽  
Author(s):  
Vivien Füstös ◽  
Tibor Erős ◽  
János Józsa
Keyword(s):  
Habitat Suitability ◽  
Fish Habitat ◽  
Round Goby ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Large River ◽  
Neogobius Melanostomus ◽  
Danube River ◽  
Habitat Evaluation ◽  
Hydrodynamical Simulations

Computational Fluid Dynamics is an effective tool for assessing non-present conditions, thus also in habitat evaluation within ecohydraulics. Deciding whether to apply a one-, two- or three-dimensional numerical approach, is an optimization that needs to be performed by every task, given the capability and the demands of specific approaches. In this paper we compare the utility of two-dimensional (2D) versus three-dimensional (3D) hydrodynamical simulations for ecohydraulic purposes. The basis of the comparation were 1) three simulated abiotic variables: water depth, depth averaged flow velocity and bed material composition, and 2) an overall performance in a meso-scale fish habitat evaluation, based on the simulated three variables. The biotic parameters for the models were the habitat suitability curves of three fish species, the Danube streber (Zingel streber), the round goby (Neogobius melanostomus) and the white bream (Blicca bjoerkna). We found that in terms of ecohydraulic utilization, the 2D approach performed sufficiently to simulate the hydrodynamics of a large river. The errors originating from the 3D-2D simplification yielded negligible differences in habitat evaluation, and the agreement in the habitat suitability indices calculated from the simulated metrics was satisfactory. Henceforth, the theory was turned into an application as we performed habitat mapping on a 100 km long, Hungarian reach of the Danube River, with the abiotic parameters resulting from a 2D hydrodynamical simulation. The possibility of simplifying the approach from 3D to 2D provides a cost-efficient numerical tool at larger scales for ecohydraulic studies, and especially for evaluating habitat suitability of riverine fish.

scholarly journals Cryptic alternative male mating strategies in invasive alien round goby (Neogobius melanostomus) of the upper Danube River

2020 ◽  
Author(s):  
Alexander F. Cerwenka ◽  
Joerg Brandner ◽  
Juergen Geist ◽  
Ulrich K. Schliewen
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Round Goby ◽  
Trophic Niche ◽  
Mating Strategies ◽  
Neogobius Melanostomus ◽  
Danube River ◽  
Life History Strategies ◽  
Male Mating ◽  
Male Mating Strategies

Abstract Male alternative mating strategies are a widespread life history choice, yet they have hardly been assessed in the context of fish invasions. As established proxies for alternative life-history strategies, body length and sexual maturity of Ponto–Caspian round goby (Neogobius melanostomus) from the recently invaded upper Danube River were contrasted and differential trophic niche occupation was assessed. Only about 4% of analyzed gobies qualified as potential sneakers which may be explained by the recent and ongoing invasion process. This study provides evidence for the occurrence of sneaking behavior of invasive round goby in the upper Danube River.

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