A field experiment on competition between Corophium volutator (Pallas) and Corophium arenarium Crawford (Crustacea:Amphipoda):Effects on survival, reproduction and recruitment
The amphipods, Corophium volutator and C. arenarium, occur abundantly on some intertidal mudflats in the Danish Wadden Sea. During a faunal survey, the two species showed a spatial segregation in their distribution along an intertidal gradient. This could not be assigned to differences in abiotic fa...
| Published in: | Journal of Experimental Marine Biology and Ecology |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
1990
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| Subjects: | |
| Online Access: | https://pure.au.dk/portal/da/publications/a-field-experiment-on-competition-between-corophium-volutator-pallas-and-corophium-arenarium-crawford-crustaceaamphipoda(cb54f39f-80c2-4a06-a78a-b8b6afdd67f1).html https://doi.org/10.1016/0022-0981(90)90057-J http://www.scopus.com/inward/record.url?scp=0025262789&partnerID=8YFLogxK |
| Summary: | The amphipods, Corophium volutator and C. arenarium, occur abundantly on some intertidal mudflats in the Danish Wadden Sea. During a faunal survey, the two species showed a spatial segregation in their distribution along an intertidal gradient. This could not be assigned to differences in abiotic factors. The possible significance of inter- and intraspecific competition amongst C. volutator and C. arenarium was investigated at various densities in experimental cages in the field. Density-dependent mortality of C. arenarium was caused by members of its own species and by C. volutator during a 4-wk period. Neither intraspecific nor interspecific density-dependent mortality could be demonstrated in C. Volutator. Interactions among the two Corophium species also influenced their fertility and recruitment. The fertility of both species was reduced by the addition of C. volutator or C. arenarium to control densities of either species. C. volutator recruits were less abundant in the Corophium -addition cages than in cages without any addition of adults (zero treatment), but the mean abundance of recruits was higher in the C. volutator treatments than in the C. arenarium treatments at the end of the experimental period. A few other species colonized the cages and among these the Nereis diversicolor recruits were less abundant in the C. arenarium treatments than in the C. volutator and the zero treatments. The field experiments indicated that adult C. volutator is competitively superior to adult C. arenarium and it is proposed that the mechanism involved is competition for space amongst adult Corophium individuals. The biotic interactions demonstrated in these experiments may maintain an existing spatial segregation between the two Corophium species. However, without a selective impact from other species C. volutator would probably have been the dominant species in this area. C. volutator has the greatest colonization rate due to its higher egg production and a better dispersal of juveniles compared to C. Arenarium. Measurements of the burrow depths of the two species suggested that C. arenarium is more protected against the most important bird predator, the dunlin Calidris alpina, than is C. volutator, due to its deeper burrow. The coexistence of the two Corophium species on this mudflat is supposed to be maintained as a result of the impact of C. alpina. But other infaunal species may also have negative impact on the abundance of Corophium. As an example, it was shown that Macoma balthica reduced the recruitment of C. volutator. |
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