Shallow Water Marine Interstitial Amphipods: Their Taxonomy and Ecology

Abstract

Shallow water marine interstitial amphipods are a relatively recently discovered suite of fauna inhabiting soft sediments. Studies of this fauna have focused primarily on their taxonomy both in the northern and southern hemispheres with little attention to their ecology. This is the first study to examine these amphipods on the east coast of Australia. The first part of this thesis provides taxonomic descriptions of four new genera and ten new species collected from coarse sediments at Lizard Island, Great Barrier Reef, Queensland and North and North-West Solitary islands in the Solitary Islands Marine Park (SIMP), Coffs Harbour, New South Wales (NSW). Descriptions are provided for: 'Solitaria smithi' gen. nov. sp. nov. (Aoridae); 'Centaurella thyeri' gen. nov. sp. nov. (Bogidiellidae); 'Guernea gollemoides' sp. nov. (Dexaminidae); 'Eriopisella skeeta' sp. nov. and 'Netamelita lacerta' sp. nov. (Melitidae); 'Saurodocus minimarenus' gen. nov. sp. nov. and 'Zepheas parspinus' gen. nov. sp. nov. (Maeridae); 'Seba mariolgae' sp. nov., 'S. towneri' sp. nov. and 'S. zeumindi' sp. nov. (Sebidae). The second part of this thesis examines the species richness, distribution and mean abundance of interstitial amphipods inhabiting coarse coral and shell sands using a partial hierarchical design, across a number of temporal and spatial scales at different depths. In addition the relationship between sediment characteristics and biotic patterns are evaluated. Overall, 16592 individuals represented by 18 families were collected from 880 core samples at North and North-West Solitary islands (SIMP), Coffs Harbour, NSW. An initial study examined the distribution and abundance of interstitial amphipods over a number of spatial scales (Site, Transect and Quadrat [1-100 m]) and across a depth gradient (4-20 m). Variation in assemblage structure was apparent at all spatial scales but patterns were not simple or consistent across the levels of each factor. However, assemblages were most abundant at 8-16 m and most speciose at 12 m.