Australian Biological Resources Study

Australian Faunal Directory


Regional Maps

Family SYCETTIDAE Dendy, 1892

Compiler and date details

John N.A. Hooper, Queensland Museum, Brisbane, Queensland, Australia; Felix Wiedenmayer (1994), Naturhistorisches Museum Basel, Basel, Switzerland; updated by John N.A. Hooper (1999)


Sycettidae Dendy, 1892 have tubular, spherical, flask-shaped, ovoid and branching growth forms, and occur as solitary sponges or in groups. The ectosomal cortex is continuous and strengthened by tangential spicules, but these do not cover the choanocyte chamber layer. Choanosomal spicules, supporting choanocyte chambers, have an articulated arrangement of overlapping sagittal triradiates (Hooper & Wiedenmayer 1994: figs 149, 155), with the angle between the paired rays larger than the angles between each paired ray and the long, unpaired ray. The sagittal triradiates have the longest ray pointing to the exterior of the sponge, and form a layer beneath the spongocoele lining (referred to as the subgastral position). Pseudosagittal spicules absent. Collar-cells are usually confined to the radial chambers in the adult, and probably always have apical nuclei. Choanocyte chambers are asconoid, tubular, being arranged radially around a central atrium (spongocoele), and the ends of chambers project to a greater or lesser extent on the ectosomal surface.

The family comprises four genera, one of which (Sycodorus) is not well known. Species are widely distributed in the world's oceans. They occur from intertidal waters to depths of at least 3800 m (Hartman, 1982). Two of these genera have published records for the Australian fauna.

Reviews and discussions can be found in Dendy (1893); Minchin (1900; unchanged); Dendy & Row (1913; unchanged); Tanita (1943; keys to Sycetta and Sycon); Hartman (1958; in Sycettida); Burton (1963; dropped); Borojevic (1967); and Hartman (1982).



Leucosolenida with a central atrial tube and perpendicular regularly arranged radial tubes lined by choanoderm. The distal cones of the radial tubes, which may be decorated with tufts of diactines, are clearly noticeable on the sponge surface. They are never covered by a cortex supported by tangential triactines and/or tetractines. The proximal skeleton of the radial tubes is composed of a row of subatrial triactines and/or tetractines, which are usually followed by only a few or several rows of triactines and/or tetractines. Distal pseudosagittal spicules are absent. A tangential layer of triactines and/or tetractines supports the atrial wall.


ID Keys

See order Leucosolenida diagnosis


History of changes

Note that this list may be incomplete for dates prior to September 2013.
Published As part of group Action Date Action Type Compiler(s)
21-Dec-2011 21-Dec-2011 MOVED
12-Feb-2010 (import)