Family CRYPTOSULIDAE Vigneaux, 1949

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Introduction

The small family Cryptosulidae Vigneaux, 1949 comprises two genera (Cryptosula Canu & Bassler, 1925, and Harmeria Norman, 1903) and perhaps three living species, including the cosmopolitan marine-fouling species Cryptosula pallasiana. Probably more is known about the anatomy of this species than any other ascophorine (Gordon 1974, 1975, 1977). In cryptosulids, the colony is encrusting and the zooids have relatively coarsely perforated frontal shields. The orifice is distinctively bell-shaped, with the broad rounded proximal rim being the widest part. There are no avicularia (or rarely a suboral avicularium), no spines, and no ovicells; brooding of embryos being internal.

Cryptosula pallasiana, the only Australian cryptosulid (Brock 1985), forms pale orange or pinkish-orange colonies (whitish where salinities are reduced) up to about 3 cm diameter on the undersides of rocks or on pilings, usually in shallow water (Bock 1982). When feeding, zooids evert lophophores of 16-17 tentacles, each 0.65-1.2 mm long depending on the age of the polypide (shorter tentacles in younger polypides). Embryos and larvae are yellowish-orange. Mostly intertidal, this species appears not to occur below the kelp zone. The species is remarkably tolerant of sediment and the fluctuating salinities and temperatures of ports and estuarine harbours. Salinities as low as 10‰ are sublethal however. Beyond its presumed Atlanto-Mediterranean home range, the species has spread very successfully to the rest of the world on the hulls of ships, at least for a century and probably much longer (Gordon & Mawatari, 1992).

The taxonomic affinities of this family are not clear. Its earliest occurrence, based on Cryptosula pallasiana, is in the Tortonian (Late Miocene) of Europe (Ghiurca, 1975).

Diagnosis

Colony forming sheets, thinly to moderately calcified. Zooids with lepralioid frontal shield with numerous pseudopores and large, bell-shaped orifice. Avicularia rare, proximal and oral. Spines and ovicells absent. Brooding in interior ovisacs of undifferentiated zooids. Colonies occur in areas of lowered salinity and are part of a world-wide fouling fauna.

General References

Bock, P.E. 1982. Bryozoans (Phylum Bryozoa). pp. 319-394 in Shepherd, S.A. & Thomas, I.M. (eds). Marine Invertebrates of Southern Australia. Handbook of the Flora and Fauna of South Australia Adelaide : Government Printer Part 1 491 pp.

Brock, B.J. 1985. South Australian fouling Bryozoans. pp. 45-49 in Nielsen, C. & Larwood, G.P. (eds). Bryozoa: Ordovician to Recent. Fredensborg : Olsen & Olsen.

Canu, F., & Bassler, R.S. 1925. Les Bryozoaires du Maroc et de Mauretanie. Mémoires de la Societe des Sciences Naturelles du Maroc 10: 5-77

Ghiurca, V. 1975. Les Bryozoaires Neogenes de la Paratethys. Documents des Laboratoires de Géologie de la Faculté des Sciences de Lyons HS 3(2): 497-518

Gordon, D.P. 1974. Microarchitecture and function of the lophophore in the bryozoan Cryptosula pallasiana (Moll). Marine Biology, Berlin 27: 147-163

Gordon, D.P. 1975. The occurrence of a gizzard in a bryozoan of the order Cheilostomata. Acta Zoologica (Stockholm) 56: 282-289

Gordon, D.P. 1977. The aging process in bryozoans. pp. 335-376 in Woollacott, R.M., & Zimmer, R.L. (eds). Biology of Bryozoans. New York : Academic Press xvii 566 pp.

Gordon, D.P., & Mawatari, S.F. 1992. Atlas of marine-fouling Bryozoa of New Zealand ports and harbours. Miscellaneous publications of the New Zealand Oceanographic Institute 107: 1-52

Norman, A. 1903. Notes on the natural history of East Finmark, Polyzoa. Annals and Magazine of Natural History 7 11: 567-598

Vigneaux, M. 1949. Révision des Bryozoaires néogènes du Bassin d'Aquitaine et essai de classification. Mémoires de la Société Géologique de France, n.s 28: 1-153

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