A morphological comparison of feeding structures among amphipod species from different habitats

North American amphipods in the families Gammaridae and Crangonyctidae are found in springs and in the subterranean. Such diverse environments are assumed to have extreme differences in food therefore the amphipods in these habitats should have differences in their structures that sense and manipulate foods. To ascertain if differences in habitat and food sources result in different morphology, thirteen species of amphipods from these two families were analyzed. The antennae, pereon, mandibles, and gnathopods were dissected from the amphipods, prepared, and viewed under the SEM. Comparisons between the surface and cave stream species and within the subterranean habitats showed that amphipods within the same species and within the same habitat had varying structures. However, maxillae I & II and the maxillipeds showed no differences in the thirteen species. Due to large variations within the habitats and species, amphipods can be categorized as generalists in terms of feeding habits and morphology.