Taxonomy of Foraminifera from Ningaloo Reef, Western Australia

Abstract

Four hundred and four species of Holocene benthic foraminifera representing 156 genera are described from the back-reef lagoon of Ningaloo Reef, Western Australia. The species are illustrated in 553 figures by over 4300 SEM and light microscope photographs of whole, dissected, sectioned or replicated specimens. Identified species are not re-described, but remarks are made on morphological features distinctive of each species and on similarities and differences between the Ningaloo Reef specimens and type material as well as specimens from elsewhere in Australia. Ten new species are described for common unidentified taxa including: the organic-cemented agglutinated Ammobaculites yardiensis; the Miliolida Quinqueloculina exmouthensis, Q. massiliniformis, Q. myagmarsuren, Q. ningalooensis and Q. tantabiddyensis; and the Rotaliida Ammonia rugulosa, Neoconorbina radiatogranulata, Pileolina haigi and Ungulatelloides cardabiaensis. About one quarter of taxa are recorded under open nomenclature as a revision of similar and related taxa is needed to clarify their status as new species or because more specimens are needed to describe a stable species concept. Unnamed species are provided with a brief description to assist with future identification. Agglutinated taxa are classified according to cement type, either organic-cemented or calcite-cemented, and recorded in alphabetical order within the genera recognised by Loeblich and Tappan (1987). All other taxa are recorded alphabetically under the orders recognised by Loeblich and Tappan (1994) and within genera recognised by Loeblich and Tappan (1987, 1994). Foraminifera are uncommon in most of the studied samples, typically constituting less than 1% of the lagoonal sediment. In channel muds and deeper water (20-30m) parts of the lagoon with a fine sandy substrate the foraminiferal diversity and abundance are highest. Immediate back-reef areas have a higher than average foraminiferal content but the diversity is low. The foraminiferal fauna is a shallow water sub-tropical assemblage with close affinities to faunas described from inner-neritic environments of the Indo-Pacific and Western Pacific regions. Many tropical species common to coral reefs of the Indo-Pacific region are absent or rare. Some species common in the cooler waters in southern parts of Australia are present or common in the samples.