Family RHABDEREMIIDAE Topsent, 1928

Museums

Regional Maps

Introduction

Sponges of the family Rhabderemiidae Topsent, 1928 have encrusting, massive, bulbous or digitate growth forms. Their skeletons lack any axial compression, and are usually plumose or plumo-reticulate, composed of light spongin fibres cored by bouquets of entirely smooth, slightly spined or entirely spined rhabdostyles (Hooper & Wiedenmayer 1994: fig. 26). Microscleres are normal or contorted sigmas (Hooper & Wiedenmayer 1994: figs 79, 80), microstyles (Hooper & Wiedenmayer 1994: fig. 107) and thraustoxeas (Hooper & Wiedenmayer 1994: fig. 114); all with or without microspines.

Members of this family are widely distributed in moderate to deep waters, ranging down to at least 2165 m depth (Hartman 1982). The family presently includes a single genus (with several synonyms). Two species are known for tropical Australian waters and another species has been described recently from McMurdo Sound, Antarctica (Van Soest & Hooper 1993).

Unlike Bubaridae, which occasionally have rhabdose bases on megascleres, the megascleres of Rhabderemiidae are always rhabdose, often acanthose, and usually produce a plumose (less often plumo-reticulate) architecture. This spicule form has probably been acquired independently by the two families. Rhabderemiidae also has several categories of peculiar microscleres, some of which are unique (or have unique modifications). Van Soest & Hooper (1993) suggest that the Raspailiidae are the close sister group to this family, although the unique microscleres in Rhabderemia make this relationship speculative.

Recent revisions are those of Hooper (1990) and Van Soest & Hooper (1993). Other reviews are in Brien et al. (1973), Bergquist (1978) and Hartman (1982).

Diagnosis

Thinly and thickly encrusting, massive, lobate, anastomosing, digitate, arborescent and lobate-flabellate growth forms; megascleres consist of smooth or distally spined monactinal choanosomal rhabdostyles bearing a basal spiral twist forming hymedesmioid, plumose, plumo-reticulate or reticulate skeletal structures, usually with poorly developed spongin fibres, with rhabdostyles usually forming diverging plumose tracts within fibres; microscleres if present include rugose oxeote or toxa-like spicules (thraustoxeas), rugose sigma-like spicules (spirosigmata, thraustosigmata) and rugose microstyles.

ID Keys

Monogeneric.

Diagnosis References

Hooper, J.N.A. 2002. Family Rhabderemiidae Topsent, 1928. pp. 511-514 in Hooper, J.N.A. & van Soest, R.W.M. (eds). Systema Porifera: A guide to the classification of sponges. New York : Kluwer Academic/Plenum Publishers Vol. 1. [511]

General References

Bergquist, P.R. 1978. Sponges. London : Hutchinson 268 pp. 12 pls 81 figs 15 tables.

Brien, P., Lévi, C., Sarà, M., Tuzet, O. & Vacelet, J. 1973. Spongiaires. pp. 1-716 485 figs in Grassé, P.P. (ed.). Traité de Zoologie. Anatomie, Systématique, Biologie. Paris : Masson et Cie Vol. 3(1).

Hartman, W.D. 1982. Porifera. pp. 640-666 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw-Hill Vol. 1.

Hooper, J.N.A. 1990. A new species of Rhabderemia Topsent (Porifera: Demospongiae) from the Great Barrier Reef. The Beagle, Records of the Museums and Art Galleries of the Northern Territory 7(1): 65-78

van Soest, R.W.M. & Hooper, J.N.A. 1993. Taxonomy, phylogeny and biogeography of the marine sponge genus Rhabderemia (Porifera: Poecilosclerida). In, Uriz, M.J. & Rützler, K. (eds) Recent Advances in Ecology and Systematics of Sponges. Scientia Marina 57(4): 319-351

History of changes