Spatial and seasonal variability in the diet of round goby (Neogobius melanostomus): stable isotopes indicate that stomach contents overestimate the importance of dreissenids

2012 ◽  
Vol 69 (3) ◽  
pp. 573-586 ◽  
Author(s):  
Jaclyn M. Brush ◽  
Aaron T. Fisk ◽  
Nigel E. Hussey ◽  
Timothy B. Johnson

Our results provide new information that diet, carbon source and trophic position of an invasive fish species, round goby ( Neogobius melanostomus ), varies seasonally, spatially and with body size in littoral habitats of Lake Ontario. Based on stomach contents and stable isotopes, round goby fed at a higher trophic position in the cooler, less productive Kingston Basin relative to the Bay of Quinte. Bay of Quinte round goby were more reliant on terrestrial carbon, whereas littoral carbon dominated in the Kingston Basin. Although stomach contents suggested dreissenids were the dominant prey item of round goby, stable isotope mixing models estimated that dreissenids were never >39% and 11% of the diet in Bay of Quinte and Kingston Basin, respectively. Stable isotopes indicated amphipods, chironomids and cladocerans were the most important prey, and were at times common items in stomach contents, but this varied with site, season and year. Given their high abundance, the impact of round gobies on the benthic biodiversity of the Great Lakes may be more significant than indicated by stomach content analysis alone.

2005 ◽  
Vol 62 (1) ◽  
pp. 15-29 ◽  
Author(s):  
David B Bunnell ◽  
Timothy B Johnson ◽  
Carey T Knight

We used an individual-based bioenergetic model to simulate the phosphorus flux of the round goby (Neogobius melanostomus) population in central Lake Erie during 1995–2002. Estimates of round goby diet composition, growth rates, and population abundance were derived from field sampling. As an abundant introduced fish, we predicted that round gobies would influence phosphorus cycling both directly, through excretion, and indirectly, through consumption of dreissenid mussels, whose high mass-specific phosphorus excretion enhances recycling. In 1999, when age-1+ round gobies reached peak abundance near 350 million (2.4 kg·ha–1), annual phosphorus excretion was estimated at 7 t (1.4 × 10–3 mg P·m–2·day–1). From an ecosystem perspective, however, round gobies excreted only 0.4% of the phosphorus needed by the benthic community for primary production. Indirectly, round gobies consumed <0.2% of dreissenid population biomass, indicating that round gobies did not reduce nutrient availability by consuming dreissenids. Compared with previous studies that have revealed introduced species to influence phosphorus cycling, round gobies likely did not attain a sufficiently high biomass density to influence phosphorus cycling in Lake Erie.


2005 ◽  
Vol 119 (4) ◽  
pp. 582 ◽  
Author(s):  
M. Brian C. Hickey ◽  
Adrienne R. Fowlie

We document the first reported occurrence of the Round Goby, Neogobius melanostomus, a small benthic fish native to the Black and Caspian seas, in the St. Lawrence River near Cornwall. On 7 September 2004, we observed approximately 20 Round Gobies while SCUBA diving at a depth of 7 m, downstream of the Saunders Generating Station at Cornwall, Ontario. Round Gobies appear to have arrived recently in this reach of the river and have not previously been detected despite extensive fish surveys conducted in the area.


2019 ◽  
Vol 48 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Yuriy Kvach ◽  
Markéta Ondračková ◽  
Michal Janáč ◽  
Vadym Krasnovyd ◽  
Mária Seifertová ◽  
...  

Abstract The round goby, Neogobius melanostomus, is a Ponto-Caspian fish species currently found in many parts of Europe, including the North Sea riverine deltas. The objective of this study was to examine the parasite community of fish caught in the lower Elbe (Süderelbe – tidal zone; Geesthacht – non-tidal) in Germany and compare it with published data from the upper Elbe (Ústí nad Labem) in the Czech Republic. Twelve parasite taxa were recorded in the lower Elbe, six in the Süderelbe and nine near the city of Geesthacht. Süderelbe fish were mainly infected with Angullicola crassus larvae, while gobies from Geesthacht – with glochidia and sporadically occurring Pomporhynchus laevis, and the opposite situation was observed at Ústí nad Labem. It appears that a large tidal weir at Geesthacht significantly contributes to the division of the round goby population, with the Geesthacht parasite community being more similar to that at Ústí nad Labem than the one from the Süderelbe, thus increasing the likelihood that shipping from Hamburg was the introduction vector to Ústí nad Labem. We also recorded Acanthocephalus rhinensis in the Elbe for the first time, and in a new host – the round goby. Thus, round gobies may represent a new vector for the introduction of this parasite along the Elbe.


2018 ◽  
Vol 75 (5) ◽  
pp. 759-771 ◽  
Author(s):  
James A. Mumby ◽  
Timothy B. Johnson ◽  
Thomas J. Stewart ◽  
Edmund A. Halfyard ◽  
Brian C. Weidel ◽  
...  

The forage fish communities of the Laurentian Great Lakes continue to experience changes that have altered ecosystem structure, yet little is known about how they partition resources. Seasonal, spatial, and body size variation in δ13C and δ15N was used to assess isotopic niche overlap and resource and habitat partitioning among the five common offshore Lake Ontario forage fish species (n = 2037; alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), round goby (Neogobius melanostomus), and deepwater (Myoxocephalus thompsonii) and slimy (Cottus cognatus) sculpins). Round goby had the largest isotopic niche (6.1‰2, standard ellipse area), followed by alewife (3.4‰2), while rainbow smelt, slimy sculpin, and deepwater sculpin had the smallest and similar niche size (1.7‰2–1.8‰2), with only the sculpin species showing significant isotopic niche overlap (>63%). Stable isotopes in alewife, round goby, and rainbow smelt varied with location, season, and size, but did not vary in the sculpin species. Lake Ontario forage fish species have partitioned food and habitat resources, and non-native alewife and round goby have the largest isotopic niche, suggestive of a boarder ecological niche, and may contribute to their current high abundance.


Author(s):  
R.I. Ruiz-Cooley ◽  
Unai Markaida ◽  
D. Gendron ◽  
S. Aguíñiga

Stomach contents and carbon (C) and nitrogen (N) stable isotope analysis were used to evaluate trophic relationships of jumbo squid, Dosidicus gigas. Buccal masses, beaks and stomach contents of large and medium maturing-sized jumbo squid and muscle from its main prey, the myctophid Benthosema panamense, were collected in the Gulf of California, Mexico during 1996, 1997 and 1999. Both the quantified C and N-isotope ratios in muscle, and stomach content analysis revealed that larger-sized maturing squid showed a higher trophic position than medium-sized individuals. However, a discrepancy between stomach contents versus stable isotope analyses was found in evaluating trophic relationships. Simple dilution models as a function of growth were used to estimate the C and N renewal dietary shift for jumbo squid. Estimates of the initial C and N pools in D. gigas with an initial age of 70 days and 210 days indicated isotopic shifts of 32% after a threefold biomass increase and 25% after a fourfold biomass increase, respectively. Additionally, beak samples of jumbo squid were evaluated as an alternative tissue to estimate squid trophic position using stable isotopes. The results showed a significant correlation between stable isotope ratios from muscle and beak samples. Muscle isotope values were higher than beak by 1% and 4% for δ13C and δ15N respectively. A test with jumbo squid beaks collected from a stomach of a stranded sperm whale confirmed the viability of this method.


Behaviour ◽  
2010 ◽  
Vol 147 (1) ◽  
pp. 121-132 ◽  
Author(s):  
Stan Yavno ◽  
Lynda Corkum

AbstractFish are known to communicate in many ways and commonly use olfactory and visual signals. When round goby (Neogobius melanostomus) males become reproductive, they change from mottled grey to black and release sex steroids in their urine. In this study, we conducted a laboratory experiment to determine if reproductive female round gobies were attracted to a combination of olfactory (urine) and visual (silicone models) stimuli, representing reproductive and non-reproductive male round gobies. Females spent significantly more time at a nest with a black reproductive male model compared with a mottled non-reproductive male model. Neither urine type nor the interaction between model type and urine affected the time spent by reproductive females at a nest. Knowledge of the reproductive habits of the round goby may enable researchers to develop a method of species control for this invasive fish by manipulating its breeding habits.


2017 ◽  
Vol 68 (1) ◽  
pp. 53 ◽  
Author(s):  
Dean Jacobsen ◽  
Søren Kock Laursen ◽  
Ladislav Hamerlik ◽  
Karen Moltesen ◽  
Anders Michelsen ◽  
...  

The fast increase in temperature on the Tibetan Plateau, with anticipated future changes in aquatic ecosystems and biodiversity, highlights the urgent need for ecological data on the sparsely studied Tibetan running waters. In the present study we surveyed eight Tibetan streams to obtain data on densities, feeding selectivity and trophic position of the stone loach Triplophysa. Benthic algae, detritus, macroinvertebrates and fish were quantified and collected for stable isotope and stomach content analysis. Triplophysa density (mean 0.70 individuals m–2, maximum 1.6 individuals m–2) decreased with altitude and increased with the percentage cover of fine substratum. Glacier-fed sites tended to have the lowest fish densities, whereas the highest densities were found near lakes. Mean fish length (4.1–9.6cm) was positively related to the percentage cover of coarse substratum. Triplophysa was omnivorous, but the composition of the stomach contents varied greatly between sites and among individuals. Algal matter was ingested at most sites, but macroinvertebrates (Chironomidae, Baetidae and Simuliidae) dominated the ingestion (average 50–100%). The trophic position of Triplophysa, identified from δ15N (‰) of the biota, varied between 2.6 and 4.2 among localities (mean 3.6) and was inversely related to the biomass of benthic algae, but unrelated to quantities of other potential food sources.


Zoodiversity ◽  
2021 ◽  
Vol 55 (4) ◽  
pp. 317-330
Author(s):  
V. Zamorov ◽  
M. Zamorova ◽  
D. Krupko ◽  
N. Matvienko ◽  
Y. Leonchyk ◽  
...  

The aim of this study was to assess the discriminability of the stocks of the round goby Neogobius melanostomus based on the shape of its otoliths. Recent otolith-shape-based species and stock discrimination studies were using otolith contours in sagittal plane and we are following this approach. We hypothesized the possibility of existence of several geographically separated populations of the round goby. Round gobies have been sampled from different locations of the North-Western Black Sea, otoliths were removed in course of the full biological analysis and photographed in sagittal plane. Principal components of the otolith contour were processed by linear discriminant analysis aiming to cross-validate the discriminability of round gobies placed at different geographical locations. This would allow demonstration of different stocks or populations. This research allows to conclude the limited applicability of otolith contours for discrimination of stocks or populations of round goby based on multiple annual samples. However, neither classification matrices of discriminant analysis nor cluster analysis dendrograms showed a single pattern except for the high year to year otoliths variability. This allows to hypothesise a strong response of contour formation to habitat and feeding conditions. However, this assumption needs to be verified by further studies.


2019 ◽  
Vol 76 (11) ◽  
pp. 1982-1992 ◽  
Author(s):  
David B. Bunnell ◽  
Steven A. Pothoven ◽  
Patricia M. Armenio ◽  
Lauren Eaton ◽  
David M. Warner ◽  
...  

Pelagic-oriented alewife (Alosa pseudoharengus) and benthic-oriented round goby (Neogobius melanostomus) are two important prey fishes in the Laurentian Great Lakes. In 2015, we evaluated their seasonal total energy (TE) across nine Lake Michigan transects. Round goby contained at least 48% more kilojoules of TE than alewife of equal length during spring and summer. TE varied spatially for both species, but only large alewife exhibited a consistent pattern, with higher values along the eastern shoreline. Variation in TE was not explained by site-specific prey densities for either species. Round goby energy density (ED) was higher in Lake Michigan than in central Lake Erie, but comparable to other regions of the Great Lakes. Alewife ED in 2015 was similar to that in 2002–2004 in Lake Michigan, with the exception of November (small alewife ED was 21% higher) and April (large alewife ED was 30% lower). Despite oligotrophication, our study suggests that starvation of juvenile and adults has not been directly contributing to overall declining prey fish abundance, although future research should evaluate the potential for overwinter starvation.


2020 ◽  
Vol 50 (5) ◽  
Author(s):  
Christina Henseler ◽  
Paul Kotterba ◽  
Erik Bonsdorff ◽  
Marie C. Nordström ◽  
Daniel Oesterwind

Abstract We examined small-scale distribution and feeding ecology of a non-native fish species, round goby (Neogobius melanostomus (Pallas, 1814)), in different habitats of a coastal lagoon situated in the south-western Baltic Sea. First observations of round goby in this lagoon were reported in 2011, 3 years before the current study was conducted, and information on this species’ basic ecology in different habitats is limited. We found that mainly juvenile round gobies are non-randomly distributed between habitats and that abundances potentially correlate positively with vegetation density and thus structural complexity of the environment. Abundances were highest in shallower, more densely vegetated habitats indicating that these areas might act as a refuge for small round gobies by possibly offering decreased predation risk and better feeding resources. Round goby diet composition was distinct for several length classes suggesting an ontogenetic diet shift concerning crustacean prey taxa between small (≤ 50 mm total length, feeding mainly on zooplankton) and medium individuals (51–100 mm, feeding mainly on benthic crustaceans) and another diet shift of increasing molluscivory with increasing body size across all length classes. Differences in round goby diet between habitats within the smallest length class might potentially be related to prey availability in the environment, which would point to an opportunistic feeding strategy. Here, we offer new insights into the basic ecology of round goby in littoral habitats, providing a better understanding of the ecological role of this invasive species in its non-native range, which might help to assess potential consequences for native fauna and ecosystems.


Sign in / Sign up

Export Citation Format

Share Document