HABITAT ARCHITECTURE AND THE ABUNDANCE AND BODY-SIZE-DEPENDENT HABITAT SELECTION OF A PHYTAL-AMPHIPOD

Examined the effect of habitat architecture (number, size, shape, and arrangement of habitable spaces and structures) created by benthic algae on the habitat selection of Gammarellus angulosus on the coast of Maine. The two primary components of habitat architecture were spatial (number and size of spaces between fronds) and structural (number, length, and width of fronds). There were significantly higher densities of amphipods in algae with branched and filamentous morphologies than in those algae with foliose and leathery macrophyte morphologies. There was also a significant correspondence between the body size of amphipods and both components of habitat architecture. When food value, predation, competition and physical disruption were excluded, patterns of abundance and body-size scaling to habitat dimensions were the same as those in the field. The spatial component (space between fronds) is an important factor in determining amphipod demographic patterns. Tenacity and crypsis are also important components in habitat selection. -from Authors