Family PACHASTRELLIDAE Carter, 1875

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Diagnosis

Astrophorida whose megascleres are calthrops, short-shafted triaenes, mesotrider desmas, or long-shafted triaenes, usually, but not always, in combination with monaxonic megascleres (typically oxeas, rarely styles or strongyles). Microscleres are streptasters and/or monaxonic microscleres, but never euasters. The ectosomal skeleton is constituted by a layer of microscleres, forming a feltwork that has occassionally been referred to as “pseudocortex”.

ID Keys

KEY TO GENERA
(1) Tetraxons being only a variety of long-shafted forms (i.e., triaenes) ------------------------------------------------- 2
Tetraxons being calthrops/short-shafted tetraxons alone or in combination with long-shafted forms ---------------- 3

(2) With cladotyles (styles with a crown of tubercles at its rounded end) -------------------------------- Cladothenea
Without cladotylotes; monaxonic megascleres being regular oxeas or styles ----------------------------------- Thenea

(3) With a number of short-shafted tetraxons becoming mesotriaena-derived desmas (mesotriders) -- Brachiaster
Tetraxons never becoming mesotrider desmas -------------------------------------------------------------------------------- 4

(4) Tetraxons with spiny rhabdome ------------------------------------------------------------------------ Acanthotriaena
Tetraxons being entirely smooth ------------------------------------------------------------------------------------------------ 5

(5) All tetraxons being pentactinal (i.e., mesotriaenes) ---------------------------------------------------- Triptolemma
Tetraxons being triactinal and tetractinal forms, alone or in combination with mesotriaenes -------------------------- 6

(6) Without streptasters --------------------------------------------------------------------------------------------- Ancorella
With streptasters ----------------------------------------------------------------------------------------------------------------- 7

(7) Without microxea-------------------------------------------------------------------------------------------------------------- 8
With microxeas ------------------------------------------------------------------------------------------------------------------ 10

(8) With toxa ----------------------------------------------------------------------------------------------------------- Dercitus
Without toxa ---------------------------------------------------------------------------------------------------------------------- 9

(9) With oval microstrongyles ----------------------------------------------------------------------------------- Pachastrella
Without oval microstrongyles; with microrhabd-like sanidasters --------------------------------------------------- Stoeba

(10) Cribiporal oscules surrounded by a palisade of protruding spicules; annulate microxeas and/or annulate
plesiasters ------------------------------------------------------------------------------------------------------------ Vulcanella
Simple oscules; uniformly spiny microxeas or, more rarely, smooth microxeas ----------------------------------------- 11

(11) Microxeas in at least two categories; streptasters never being plesiasters --------------------------- Characella
Microxeas in one category; streptasters always including plesiasters -------------------------------------- Poecillastra

Diagnosis References

Maldonado, M. 2002. Family Pachastrellidae Carter, 1875. pp. 141-162 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. [141]

General References

Bergquist, P.R. 1978. Sponges. London : Hutchinson 268 pp. 12 pls 81 figs 15 tables.

Brien, P., Lévi, C., Sarà, M., Tuzet, O. & Vacelet, J. 1973. Spongiaires. pp. 1-716 485 figs in Grassé, P.P. (ed.). Traité de Zoologie. Anatomie, Systématique, Biologie. Paris : Masson et Cie Vol. 3(1).

Hartman, W.D. 1982. Porifera. pp. 640-666 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw-Hill Vol. 1.

Lendenfeld, R. von 1903. Tetraxonia. In Schulze, F.E. (ed.) Das Tierreich. Berlin : Friedländer Lf 19 168 pp. 44 figs.

Maldonado, M. 1993. The taxonomic significance of the short-shafted mesotriaene reviewed by parsimony analysis: validation of Pachastrella ovisternata Lendf. (Demospongiae: Astrophorida). Bijdragen tot de Dierkunde 63(3): 129-148

Maldonado, M. 2002. Family Pachastrellidae Carter, 1875. pp. 141-162 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.

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