Round goby versus marbled crayfish: alien invasive predators and competitors

Aquatic biodiversity is threatened by spread of invasive alien species. Round goby Neogobius melanostomus is an invasive fish in large European rivers as well as in coastal waters near their mouths and marbled crayfish Procambarus virginalis is a highly invasive crustacean. Both are small, bottom-dwelling species occupying similar habitat and shelters and utilizing similar food sources. We hypothesized that goby presents a threat to both native and non-native astacofauna in invaded ecosystems. We tested this through laboratory experiments designed to determine aggressiveness and competitiveness of goby against marbled crayfish as a model for other North American cambarid crayfish, assessing goby prey size selection and competition with marbled crayfish for space and shelter. Gobies showed high aggressiveness and dominance over the crayfish. Goby predation on juvenile crayfish was limited by mouth gape size. In goby/crayfish pairs of similar weight, gobies were more aggressive, although each affected the behavior of the other.

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Gorging on gobies: beneficial effects of alien prey on a threatened vertebrate

Canadian Journal of Zoology ◽

10.1139/z05-182 ◽

2006 ◽

Vol 84 (1) ◽

pp. 108-115 ◽

Cited By ~ 94

Author(s):

R B King ◽

J M Ray ◽

K M Stanford

Keyword(s):

Invasive Species ◽

Body Size ◽

Round Goby ◽

Neogobius Melanostomus ◽

Food Sources ◽

Ecological Communities ◽

Positive Effects ◽

Water Snake ◽

Round Gobies ◽

Water Snakes

Invasive species often have rapid and far-reaching negative impacts on populations and ecological communities. These effects are most common when invasive species have few competitors or predators. Although higher level carnivores do consume invasive species, quantitative effects of new and abundant food sources on predators have rarely been documented and, as a consequence, potentially positive effects of invasive species may be under appreciated. We investigated the effects of the invasive round goby (Neogobius melanostomus (Pallas, 1814)) on diet composition, growth rate, and body size of the Lake Erie Water Snake (Nerodia sipedon insularum (Conant and Clay, 1937)), which is threatened in the USA and endangered in Ontario, Canada. Water Snakes have shifted their diet, and round gobies now constitute >92% of prey consumed. This shift in diet has occurred in just one or two Water Snake generations, yet has resulted in more rapid growth and attainment of larger body size in Water Snakes. These positive effects may reduce predation, speed reproductive maturity, increase offspring production, and fuel population growth of this threatened species.

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Morphometric variability in round goby Neogobius melanostomus (Perciformes: Gobiidae) from the Sea of Azov

Zoosystematica Rossica ◽

10.31610/zsr/2017.26.2.392 ◽

2017 ◽

Vol 26 (2) ◽

pp. 392-405 ◽

Cited By ~ 1

Author(s):

O.A. Diripasko ◽

T.A. Zabroda

Keyword(s):

Round Goby ◽

Joint Effect ◽

Neogobius Melanostomus ◽

Sea Of Azov ◽

Morphometric Characters ◽

One Dimensional ◽

The Sea Of Azov ◽

Size Dependent ◽

Size Variability ◽

Males And Females

A total of 38 morphometric characters of the round goby Neogobius melanostomus melanostomus (Pallas, 1814) were studied in its native range in the Sea of Azov. The aim was to assess joint effect of sexual dimorphism and size variability on overall variability within groups of samples (populations) using appropriate methods of traditional statistical analysis (one-dimensional and multivariate statistics). Sex and size-dependent variability was studied based on model samples of males and females of different size. Most of the studied morphometric characters of round goby from the Sea of Azov demonstrated statistically significant sex- and size-dependent in-group variability. The pattern of the variability suggests that, for a comparison of round goby from different sea regions and between populations, separate samples of males and females within the range 9–13 cm SL should be examined in order to minimise the effect of the size and sex factors. The approach of searching for the most informative size range could be useful not only for further studies of infraspecific variation but for comparisons between morphologically close gobiin species.

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

Oceanological and Hydrobiological Studies ◽

10.1515/ohs-2015-0048 ◽

2015 ◽

Vol 44 (4) ◽

Cited By ~ 7

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.

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