Family GRANTIIDAE Dendy, 1892

Museums

Museum list

Regional Maps

Family GRANTIIDAE 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)

Introduction

Grantiidae Dendy, 1893 are very variable and include encrusting, lobate, tubular, sac-shaped, ovoid, spherical, vase-shaped and many other growth forms, either solitary or grouped and sessile, substipitate, or stipitate. The surface has a distinct dermal cortex and a proper cortical skeleton of tangential radiates (Hooper & Wiedenmayer 1994: fig. 158), sometimes supplemented by, and occasionally replaced by, oxeas (Hooper & Wiedenmayer 1994: figs 164–174). The ectosomal cortex sometimes has quadriradiates (Hooper & Wiedenmayer 1994: fig. 158) in association with choanosomal triradiates (Hooper & Wiedenmayer 1994: figs 147–153). The skeleton of the chamber layer ranges from regularly articulate to irregularly scattered, typically with subgastral sagittal radiates (Hooper & Wiedenmayer 1994: fig. 155). Some subdermal pseudosagittal triradiates may occur, but these are regarded as derived from normal choanosomal spicules, and do not form a continuous distict layer as in the Heteropiidae. Subdermal quadriradiates (Hooper & Wiedenmayer 1994: figs 157, 158), if present, are always associated with the chamber-layer skeleton containing confused triradiates. Nuclei of collared cells are probably always apical. Choanocyte chambers are asconoid, elongate and radially arranged, or small, spherical and irregularly scattered in the choanosome (leuconoid).

The Grantiidae includes 25 recognised genera, among which 14 are recorded in the Australian fauna. The family has a generally widespread geographical distribution and occurs from intertidal habitats to depths of at least 2195 m (Hartman 1982).

Haeckel (1872) established Leucones as a supra-generic group for Leuconia and other genera, and it was later used at subfamily level by de Laubenfels (1936). Prior to Dendy (1893), both Leuconiinae Haeckel, 1872 and Grantiinae Lendenfeld, 1885 were used only at the subfamily level. We accept that Leuconiidae Haeckel, 1872 has priority over Grantiidae Dendy, 1893 under the ICZN: Art. 36a (Principle of co-ordination in family group taxa and names), however, we are reticent to change the established use of Grantiidae pending a thorough review of the order.

Reviews are available in Lendenfeld (1885a); Lendenfeld (1885b; as Grantinae); Dendy (1893a, 1893b; with Grantia, Grantiopsis, Ute, Synute, Utella, Anamixilla, Sycyssa, Leucandra, Lelapia, Leucyssa); Dendy & Row (1913; Lelapia removed to Lelapiidae; the following added: Teichonopsis, Sycute, Achramorpha, Uteopsis, Megapogon, Baeria, Leucopsilla, Aphroceras, Leucettaga, Paraleucilla, Lamontia, Trichogypsia, Kuarrhaphis, Eilhardia); Tanita (1943; key to genera); Hartman (1958; family referred to Sycettida); Borojevic (1966, 1968; discussion, differentiation from Heteropiidae); and Hartman (1982).

Diagnosis

Leucosolenida in which there is always a cortex, supported by a skeleton of tangential spicules that can be diactines, triactines, tetractines, or any combination of these. The aquiferous system is either syconoid with radial and elongate choanocyte chambers, or sylleibid or leuconoid with elongate or spherical, scattered choanocyte chambers. The inhalant and exhalant aquiferous systems are always fully developed. The choanoskeleton is articulate, tubular in syconoid species, and contains few to several rows of triactines and/or tetractines, or is, in leuconoid species, arranged without apparent order. In the latter case, the choanoskeleton always preserves traces of the radial organisation, particularly at the level of the subatrial triactines and/or tetractines. The atrial skeleton consisting of tangential triactines and/or tetractines is well developed.