Family Desmoxyidae Hallmann, 1917

Abstract

Desmoxyidae Hallmann (Demospongiae, Halichondrida) contains 19 genera, 10 of which are recognised here, and probably less than 100 species worldwide. Desmoxyids are widely distributed and live mainly in shallow coastal waters but a few have also been recorded from 1300m depth. Major morphological characters diagnostic for the family include spined or smooth diactinal microscleres (oxeas or strongyles), often centrangulate or strongly bent centrally, localised in the ectosomal region; choanosomal skeleton with monactinal (styles or tylostyles) and/or diactinal spicules forming confused reticulate tracts or widely spaced, irregular multispicular bundles bound together by sparse collagen, or enclosed in poorly developed fibres; microscleres also sometimes include raphides occurring singly or in bundles (trichodragmata), or acanthose microrhabds (sanidaster-like), acanthose cladotoxa and birotules.