Family AXINELLIDAE Carter, 1875

Museums

Regional Maps

• Alvarez De Glasby, B. & Hooper, J.N.A. 2002. Family Axinellidae Carter, 1875. pp. 724-747 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. [724]

Introduction

Characteristics
Hooper & Wiedenmayer (1994: 69) gave a comprehensive definition of the family as: 'encrusting, massive, branching, fan shaped, and tubular; surface usually hispid due to projecting spicules; megascleres are styles, oxeas, strongyles (sometimes sinuous) in all combinations, usually smooth, sometimes tuberculate, spined, flexuous or vermiform; skeleton typically divided into axial and extra-axial components; main skeletal tracts, both spicules and spongin fibres, typically condensed in axial portion of skeleton, with extra-axial plumose or plumoreticulate tracts running to surface; encrusting species having condensed basal skeleton usually with basal flexuous or vermiform strongyles, and perpendicular extra-axial skeleton of styles (straight or rhabdose), or oxeas. Microscleres usually absent, although few genera having raphides or microraphides in groups (trichodragmata) or alone'. Hooper & Lévi (1993b) and Hooper & Wiedenmayer (1994) recognised the poor value of the characters included in this definition, the occurrence of many exceptions to the general pattern and the poor understanding of the affinities of many of the included species. The paucity of reliable diagnostic characters creates a problem at the infra-family level. Many of the nominal genera assigned to the Axinellidae have skeletal structures different to the axinellids in the sense of Hooper & Wiedenmayer (1994). Furthermore, most of these genera are polythetic, in that they cannot be defined by a single set of diagnostic characters. This makes allocation of species problematical, and raises the likelihood that genera contain heterogeneous assemblages of species.

Alvarez & Hooper (2002) subsequently modified the definition to restrict Axinellidae to genera without specialised ectosomal skeleton and velvety or microhispid surface; with choanosomal skeleton predominantly plumose to plumoreticulate, mainly formed by spicule tracts of sinuous strongyles, oxeas, anisoxeas or styles and without microscleres other than raphides and trichodragmata. Some dictyonellid genera (e.g. Acanthella, Stylissa and Rhaphoxya) have skeletal arrangement similar to some genera of Axinellidae (e.g. Axinella) but the surface features in those cases are very characteristic of Dictyonellidae.

This revised definition also excludes encrusting forms (i.e. Bubaris, Bubaropsis, Cerbaris, Hymerhabdia, Lithobubaris, Monocrepidium, Rhabdobaris, Rhabdoploca, Skeizia and Uplexoa). These were included in Axinellidae at one time or another based on the similarities between the axial condensation of the skeleton of Axinellidae and the 'basally condensed' skeleton of encrusting forms such as Bubaris (see Bergquist 1970; Van Soest et al. 1990). They are now transferred to Bubaridae sensu Topsent, 1928c and Desmanthidae.

Alvarez & Hooper (2009) provided further information on the current status of the family, and noted that species allocated to some genera (e.g. Axinella, Acanthella, Phakellia) have fuzzy boundaries and overlapping characters; include numerous forms (or varieties/morphs); and that some allegedly widely distributed species may represent complexes of cryptic species hiding under morphotypes that span a continuum, and which cannot be resolved easily using morphometric data alone. It is anticipated that this family in particular, of the Halichondrida, will benefit greatly by the inclusion of molecular datasets.

Scope
Of the 92 nominal genera erected in, or transferred to, the family at one time or another, only 24 genera belong in the Axinellidae with 11 valid genera (i.e., Auletta, Axinella, Cymbastela, Dragmacidon, Dragmaxia, Pararhaphoxya, Phakellia, Phycopsis, Pipestela, Ptilocaulis, Reniochalina) and the rest considered junior synonyms. The total number of species in the family according to Hooper & Lévi (1994) is approximately 300 worldwide, but given the uncertainties in the taxonomy of this family the actual number may differ substantially above or below that figure.

Distribution
Axinellidae has a cosmopolitan distribution without any obvious or distinct centre of diversity. Regional revisions record 15 species for New Caledonia (Hooper & Lévi 1993b), 11 for New Zealand (Bergquist 1970), 9 for the Northern Territory of Australia (Alvarez & Hooper 2009), 21 (in 7 genera) from the Central-West Atlantic region (Alvarez et al. 1998) and 17 for the NE Atlantic (Van Soest et al. 2000). Other estimates are: 57 species described for Australia (Hooper & Wiedenmayer 1994); 130 species from the Indo-west Pacific region, of which 45% are represented in Australian waters (Hooper & Lévi 1994); 63 species for the South China Sea (Hooper et al. 2000b) and 30 for the Mediterranean (Van Soest, unpublished data).

Reviews: Carter 1883b: 316; Ridley 1884a: 462; Carter 1885d: 347; Ridley & Dendy 1886: 477; Ridley & Dendy 1887:166; Topsent 1894c: 24-25; Dendy 1897: 231; Wilson 1902: 399; Topsent 1904b: 137; Dendy 1905: 181; Row 1911: 354; Hentschel 1912: 113; Dendy 1916a: 96; Hallmann 1917c: 673-674; Dendy 1922b: 111; Wilson 1925: 444; de Laubenfels 1936a: 127; de Laubenfels 1950a: 87; Bergquist 1970; Lévi 1973: 605; Wiedenmayer 1977b: 151-152; Bergquist 1978: 167; Hartman 1982; Tanita & Hoshino 1989: 84; Hooper & Lévi 1993b: 1396; Hooper & Wiedenmayer 1994: 69; Alvarez et al. 2000a; Alvarez & Hooper 2009: 17.

Database Notes

Synonymy. [Phakellidae] Gray, 1867a: 503, 518; Gray, 1872a: 447 (nomen oblitum, Article 23.9 ICZN (Anon., 1999)). Axinellidae Carter, 1875c; Lendenfeld, 1889a:903 (in part); de Laubenfels, 1936a: 127 (in part).

Diagnosis

Encrusting, massive, branching, fan-shaped and tubular; generally red, orange or yellow sponges; surface is usually velvety to hispid due the projection of choanosomal spicules and without specialised ectosomal skeleton. Choanosomal skeleton is formed by ascending spiculo-fibres that radiate to the periphery, connected irregularly by loose spicules and short tracts, and ending in skeletal projections at the surface, or plumoreticulate with ascending plumose tracts of oxeas and styles connected regularly by paucispicular or multispicular tracts, or reticulated with main spicule tracts of sinuous or vermiform strongyles, or anisoxeas, plumo-echinated by single spicules. In some species the choanosomal skeleton is divided into an axial region, where often becomes compressed, and an extra-axial region with plumoreticulated skeleton. Megascleres are mainly oxeas, anisoxeas with or without telescoped tips or microspines, straight or sinuous styles, strongyles are always sinuous. Microscleres are raphides, single or in trichodragmata, generally difficult to observe and located near the periphery.

ID Keys

KEY TO GENERA
(1)Choanosomal skeleton with ascending and anastomosing tracts radiating to periphery; spicule tracts are coring spongin fibres, and/or fibrofascicles ------------------------------------------------------------------------------------------------- 2
Choanosomal skeleton with spicule tracts of sinuous strongyles plumo-echinated (radiating obliquely and perpendicularly) by styles or oxeas -------------------------------------------------------------------------------------------------- 4
Choanosomal skeleton plumoreticulate, or with a loose reticulation of plumose spicules --------------------------------- 5
Choanosomal skeleton consisting of plumose axes of spicules, dendritically branching and rarely interconnected, with peripheral spicules curving outward. Megascleres are only styles, some bent near the base. Microscleres are long sinuous trichodragmata and single raphides ornamented with fine spines at terminal points -- Dragmaxia

(2) Flat spatula-shaped scopiform processes at surface ----------------------------------------------------------------------- 3
Long and filamentous processes at surface -------------------------------------------------------------------- Phycopsis

(3) Megascleres are anisoxeas with or without spined tips ---------------------------------------------- Reniochalina
Megascleres are styles in two size categories ------------------------------------------------------------------ Ptilocaulis

(4)Body generally fan-shaped and stalked; with ascending choanosomal tracts of strongyles interconected and plumo-echinated by single or short tracts of styles. Main tracts often imprinting the surface as 'veins' ----------------------------------------------------------------------------------------------------------------------------------------------- Phakellia
Body generally tube-shaped and stalked; with a layer of sinuous strongyles lining the inner wall of the tube and a reticulation, nearly isotropic of choanosomal tracts of strongyles plumo-echinated by styles. Surface free of skeletal projections but with single spicules ----------------------------------------------------------------------------------- Auletta
Body generally dichotomously branching and stalked, with a main axial core of interwoven strongyles echinated by single oxeas or short plumose tracts of oxeas ------------------------------------------------------------Pararhaphoxya

(5) Plumoreticulate, with styles and oxeas. Microscleres, if present, are trichodragmata ---------------------------------- 6
Plumoreticular, no styles, body generally cup-shaped and stalked -------------------------------------- Cymbastela
Loose reticulation of plumose and wavy paucispicular to multispicular tracts of relatively thin oxeas; body tubular or cylindrical growth forms ---------------------------------------------------------------------------------------------- Pipestela

(6)Massive or massive encrusting forms; plumose tracts are generally thick and multispicular ---------- Dragmacidon
Body branching, arborescent or bushy; plumose tracts are pauci-multispicular, connected at regular intervals by uni-paucispicular secondary tracts ------------------------------------------------------------------------------------- Axinella

Diagnosis References

Alvarez, B. & Hooper, J.N.A. 2009. Taxonomic revision of the order Halichondrida (Porifera: Demospongiae) from northern Australia. Family Axinellidae. The Beagle, Records of the Museums and Art Galleries of the Northern Territory 25: 17-42 [17]

Alvarez De Glasby, B. & Hooper, J.N.A. 2002. Family Axinellidae Carter, 1875. pp. 724-747 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. [724]

General References

Alvarez De Glasby, B. & Hooper, J.N.A. 2002. Family Axinellidae Carter, 1875. pp. 724-747 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.

History of changes