Species Interactions in Cave Stream Communities: Experimental Results and Microdistribution Effects
Culver DC, Fong DW, Jernigan RW. 1991. Species Interactions in Cave Stream Communities: Experimental Results and Microdistribution Effects. The American Midland Naturalist. 126(2):364-379
The interspecific interactions of three pairs of cave isopods and amphipods, previously thought to be competitors, were examined by analyzing washouts and losses from laboratory streams and from manipulation experiments in streams of Organ Cave, West Virginia. None of the pairs were in fact competitors. The isopod Caecidotea holsingeri was an amensalist of the amphipod Stygobromus spinatus in the laboratory, but the two did not interact in the field. The amphipod Gammarus minus was a predator on C. holsingeri both in laboratory streams and in the field, and C. holsingeri was a competitor of G. minus, at least in laboratory streams. Stygobromus emarginatus was an amensalist of G. minus in laboratory streams and in the field; but in the field G. minus was a commensalist of S. emarginatus. This combination of commensalism and amensalism produces the dynamics of a predator-prey system. Interactions in both laboratory streams and cave streams were asymmetric and often had characteristics of several kinds of interspecific interactions. Negative interactions dominated in laboratory streams while positive interactions were more common in the field experiments. Negative interactions had an effect on microdistribution only at the level of individual stones in a riffle. Positive interactions may contribute to the positive association of some species at larger scales.
- Type
- Journal Article
- Authors
- Culver, David; Fong, Daniel; Jernigan, Robert
- Units
- MACA
- Keywords
- Amphipods (Amphipoda), Animal Studies, Caecidotea holsingeri (isopod), Caves, Gammarus minus (amphipod), Isopods (Isopoda), Stygobromus emarginatus (amphipod), Stygobromus spinatus (amphipod)