Carter, 1875
Definition: Encrusting, massive, lobate, fan-shaped and branching growth forms. Ectosomal skeleton composed of subtylostyles or anisoxeas (exceptionally oxeas), in erect bundles forming a continuous crust, lying tangential or sparsely dispersed on the surface. Subectosomal skeleton relatively poorly developed. Choanosomal skeleton with well developed spongin fibres forming hymedesmoid skeleton, microcionid skeleton, plumose skeleton, plumoreticulate skeleton, reticulate skeleton or axially condensed tracts. Spongin fibres cored by smooth or partially spined large styles, and echinated by smooth, wholly- or partially-spined small echinating styles or modified forms (aacantho-xeas or acantho-strongyles) embedded perpendicular to fibres (echinating acanthostyle). Microscleres typically palmate chelae, sometimes contort and thickened (pseudo-anchorate, -arcuate) and also toxas and occasionally raphides or microxeas. Sexual reproduction is exclusively viviparous.
Remarks: This family is possibly the most abundant and diverse of any family of Porifera. 570 nominal species have been erected of which 436 are probably valid, and there are over 50 other known (collected) undescribed species in the Indo-west Pacific alone. These species are widely distributed in all the world's oceans, although there are two peaks of biodiversity: one in the tropical Indo-Malay and Australian region, and the other in the northwest Atlantic (Hooper and Lévi, 1993). Microcionids have been recorded from intertidal habitats to depths of at least 2460 m (Hartman, 1982). Small, incrusting Clathria (Microciona ) and C . (Thalysias ) species are particularly common in the interstices of coral reefs, bonding and/or bioeroding the coralline substrate, and it is likely that the biodiversity of this group will rise dramatically once investigators focus on that habitat.
There are 75 nominal genera which have been previously included in Microcionidae, of which 68 are currently recognised as (potentially) residing within the family although most of these have been merged with other well established taxa (e.g. Lévi, 1960a; Simpson, 1968a; van Soest, 1984b; Hooper, 1988b, 1990; Hooper and Lévi, 1993). Six genera and 14 subgenera are currently recognised, of which three (one with two subgenera) are included here. Recent revision: Hooper (1996).
Source: Hooper, 1996.
Genera represented in the area:
Antho Gray, 1867 (syn. Anomoclathria Topsent, 1929; Anthoarcuata Bakus, 1966, Clathriella Burton, 1935; Dictyoclathria Topsent, 1920; Dirrhopalum Ridley, in Ridley and Duncan, 1881; Heteroclathria Topsent, 1904; Holoplocamia de Laubenfels, 1936; Isociona Hallmann, 1920; Isopenectya Hallmann, 1920; Jia de Laubenfels, 1930; Lissoplocamia Brøndsted, 1924; ? Naviculina Gray, 1867; [Plocamia] Schmidt, 1870 [preocc.]; Plocamilla Topsent, 1928; Plocamiopsis Topsent, 1904; Quizciona de Laubenfels, 1936): ectosomal skeleton with tangential or erect-plumose auxiliary styles, choanosomal skeleton a basal or axial renieroid skeleton composed of acanthostyles, acanthostrongyles or smooth 'dumbell spicules', with a secondary dendritic, plumose, plumoreticulate or simply echinating skeleton of smooth choanosomal styles arising from fibre nodes (erect forms), or ascending upwards from basal spongin (encrusting forms), echinating acanthostyles present or absent, microscleres include palmate isochelae, including modified (cleistochelae) and more contort forms, pseudoarcuate isochelae, modified sigmoid isochelae (crocae), and smooth or spined toxas of several forms. (Three subgenera are recognized but in the area only the nominal subgenus is represented) (Antho involvens).
Artemisina Vosmaer, 1885 (syn. ? Qasimella Thomas, 1974)—choanosomal confused skeleton with halichondroid tracts, vaguely ascending, composed of principal styles without definite spongin fibres, extra-axial skeleton radially arranged with 1 category of auxiliary style forming paratangential bundles on the surface, echinating spicules absent, microscleres are palmate isochelae and toxas with spined points.
Clathria Schmidt, 1862 (syn. Aaata sensu de Laubenfels, 1930; Abila Gray, 1867; Anaata de Laubenfels, 1932; Antherochalina Lendenfeld, 1887; Aulenella Burton and Rao, 1932; Axociella Hallmann,1920; Axocielita de Laubenfels, 1936; Axosuberites Topsent, 1893; Bipocillopsis Koltun, 1964; Cionanchora de Laubenfels, 1936; Clathriopsamma Lendenfeld, 1888; Colloclathria Dendy, 1922; Damoseni de Laubenfels, 1936; Dendrocia Hallmann, 1920; Dictyociona Topsent, 1913; Echinonema Carter, 1881; Fisherispongia de Laubenfels, 1936; Folitispa de Laubenfels, 1936; Hymantho Burton, 1930a; Isociella Hallmann, 1920; Labacea de Laubenfels, 1936; Leptoclathria Topsent, 1928; Ligrota de Laubenfels, 1936; Litaspongia de Laubenfels, 1936; Marleyia Burton, 1931; Microciona Bowerbank, 1863; Ophlitaspongia Bowerbank, 1866; Paradoryx Hallmann, 1920; Paratenaciella Vacelet and Vasseur, 1971; Pitalia Gray, 1867; Pseudanchinoe Burton, 1929; Ramoses de Laubenfels, 1936; Rhaphidophlus Ehlers, 1870; Seriatula Gray, 1867; Sophax Gray, 1867; Stylotellopsis Thiele, 1905; Tenacia Schmidt, 1870; Tenaciella Hallmann, 1920; ? Thalassodendron Lendenfeld, 1888; Thalyseurypon de Laubenfels, 1936; Thalysias Duchassaing and Michelotti, 1864; Wetmoreus de Laubenfels, 1936; Wilsonella Carter, 1885): choanosomal skeletal tracts usually enclosed within reticulate spongin fibres, sometimes simply with nodal spongin, usually composed of principal styles well differentiated in geometry from auxiliary styles, sometimes principal styles are absent and fibres are cored by auxiliary spicules or by foreign detritus; 0, 1 or 2 categories of auxiliary styles form subectosomal amd ectosomal skeletons, usually either tangential or plumose in structure; echinating acanthostyles unmodified, usually spined, sometimes smooth, sometimes absent; microscleres are commonly palmate isochelae, including modified (cleistochelae) and contort forms (less often thickened to resemble pseudo-arcuate, -anchorate or -sigmoid isochelae), and smooth or spined toxas, and microxeas in 1 species.
Seven subgenera are recognized, of which two are recognized in the area:
Clathria (Clathria ) : with single category of auxiliary styles forming ectosomal and subectosomal skeletons, differentiated from category of principal styles in the choanosomal skeleton.
Clathria (Microciona ) : hymedesmoid choanosomal skeleton composed of basal spongin fibres lying on substrate, with ascending non-anastomosing fibre nodes (microcionid skeleton), and erect principal, echinating and auxiliary spicules perpendicular to substrate (Clathria atrasanguinea V).
Species included:
Antho brattegardi
Antho circonflexa
Antho coriacea
Antho dichotoma
Antho erecta
Antho inconstans
Antho involvens
Artemisina arciger
Artemisina transiens
Clathria acanthotoxa
Clathria armata
Clathria ascendens
Clathria atrasanguinea
Clathria barleei
Clathria basifixa
Clathria bitoxa
Clathria coralloides
Clathria ctenichela
Clathria duplex
Clathria elliptichela
Clathria fallax
Clathria gradalis
Clathria intermedia
Clathria macrochela
Clathria normani
Clathria osismica
Clathria seriata
Clathria spinarca
Clathria strepsitoxa
Clathria toxitenuis
Species not treated here:
Clathria anchorata (Carter, 1876), deep-water (below 450 m)
Clathria dianae (Schmidt, 1875), Norway, cf. Arndt, 1935: 79
Clathria ditoxa (Stephens, 1916), Ireland, deep water
Clathria hjorti (Arnesen, 1920), Iceland, deep water
Clathria laevis (Bowerbank, 1866), Shetland, Sweden, cf. Arndt, 1935: 79, fig. 162
Clathria microchela (Stephens, 1916), Ireland, deep water
Clathria primitiva (Koltun, 1956), Iceland, Spitzbergen, deep water
Clathria tenuissima (Stephens, 1916), Ireland, deep water