Document details
Document title
A large testate protist, Gromia sphaerica sp. nov. (Order Filosea), from the bathyal Arabian Sea
GOODAY A. J. ; BOWSER S. S. ; BETT B. J. ; ...
The deep ocean provides a habitat for several large testate protistan taxa, e.g., xenophyophores and komokiaceans. However, testate amoebae (orders Lobosea and Filosea) have never been reliably reported from below 270 m depth. Here we describe large spherical protists, up to almost 40 mm diameter, recovered in box core, multicore, and epibenthic sledge samples taken on the continental slope off Oman (NW Arabian Sea) during RRS Discovery Cruise 211. Specimens consist of an organic envelope, with numerous tiny apertures, enclosing a mass of fine waste pellets (stercomata). On the basis of its wall ultrastructure (revealed by high-voltage transmission electron microscopy), this organism is identified as a member of the filosean genus Gromia. It is described herein as Gromia sphaerica sp. nov. The wall is layered and includes the honeycomb membrane', a structure that is unique to this genus. The new species is the first gromiid to be reported from the deep sea. It lives between about 1200 and 1630 m below the main oxygen minimum zone, in an area where bottom-water oxygen concentrations are around 0.47 ml l-1. The new gromiid species is clearly visible in bottom photographs taken at 1273 m (2.7 individuals m-2), 1318 m (2.7 indiv. m-2), 1624 m (17.3 indiv. m-2) and 1633 m (76.5 indiv. m-2). They lie partly embedded in the seafloor and are sometimes grouped in twos and threes. Specimens are typically surrounded by an apron of lighter-coloured sediment,
ISSN : 0967-0645
Deep-sea research. Part 2. Topical studies in oceanography Y. 2000, vol. 47, No. 1-2, pages 55-73 [bibl. : 1 p.3/4]
This document can be reproduced free for members of the CNRS community.
For members of communities outside the CNRS, the paid reproduction of this document is subject to the authorization of the Centre Français d’Exploitation du Droit de Copie (Copyright authorities).

To use our services (strictly reserved for members of the CNRS (National Center for Scientific Research), French Higher Education and Research and public sector communities in France and other countries):