Ecology of free-living nematodes from the continental shelf of the central great barrier reef province

• Published in: Estuarine, coastal and shelf science Vol. 32; no. 5; pp. 421 - 438
• Main Author: Tietjen, John H.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 1991; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; carbonate sediments; continental shelf; diversity; ecology; Fundamental and applied biological sciences. Psychology; Great Barrier Reef (Australia); Marine; Nematoda; nematodes; Spilophorella paradoxa; Theristus; Australia; Oceania; Great Barrier Reef; carbonate sediments; continental shelf; ecology; diversity; Great Barrier Reef (Australia); nematodes; Marine environment; Species diversity; Continental shelf; Trophic structure; Helmintha; Nemathelminthia; Invertebrata; Sediments; Nematoda; Population density
• ISSN: 0272-7714; 1096-0015
• DOI: 10.1016/0272-7714(91)90032-7

Nematode assemblages from five sites on the continental shelf of the central Great Barrier Reef (GBR) along a transect ranging from inshore muddy quartz to offshore carbonate sands were examined in austral spring (October 1987) and summer (January 1988). Assemblages at all sites were characterized by very even distributions (low dominance) of families, genera and species. Average per cent abundances of the dominant family (Chromadoridae), genus ( Theristus) and species ( Spilophorella paradoxa), respectively, were 16, 10 and 8% of the total number of specimens identified. The diversity of species ( H′ = 3·35–4·08) from the GBR was higher than that normally calculated for shelf nematode assemblages; species richness (SR = 10·64–16·67) and evenness (J′ = 0·82–0·91) values approximate those characteristic of deep-sea nematode assemblages, suggesting equitable exploitation of the interstitial environment on the GBR shelf by many species. This was also indicated by a nodal analysis of the 22 dominant species, which exhibited no strong preference for any particular sediment or site. Non-selective deposit and epistrate feeders were the most abundant trophic types among the nematodes. The abundance of non-selective deposit feeders was significantly greater in the summer than spring assemblages, accompanying differences also observed in the per cent composition of several species. Shortterm fluctuations in species composition and high species diversity of nematodes on the central Great Barrier Reef shelf may be the result of high sediment heterogeneity (caused by cyclones and frequent prawn trawling), a rich bacterial flora, continuous warm temperatures and low macroinfaunal abundance.