Hancock, 1849
Species Overview
Cliona lobata Hancock, 1849 is a yellow excavating sponge boring exclusively in shells. It differs from C . celata which may occur in the same shells in the much smaller and more numerous papillae and the thinner galleries. In contrast to C . celata it has always microscleres (microscopic examination necessary). C . vastifica is similar in papillae size but differs in being orange-red. C . lobata occurs sympatrically with C . celata over much of its range, although it is more common in northern waters. It is less frequently reported than C . celata .
Taxonomic Description
Colour: Papillae pale yellow, interiorly golden yellow.
Shape, size, surface and consistency: Excavating sponge making thin branching galleries in mollusc shells, notably Mytilus , Ostrea , Buccinum , Cardium and Mactra . Papillae small and numerous. Inhalant papillae 0.2-0.5 mm in diameter, exhalant papillae up to 1.6 mm in diameter. Galleries are less than 1.5 mm in diameter. Consistency soft.
Spicules: (Cliona lobata spics) Tylostyles and spirasters. Megascleres : Tylostyles slightly fusiform with a sharp point: 155-400 x 1-4 µm.
Microscleres : Spirasters, variable in length, with 1-9 curves: 10-65 x 2-4.5 µm.
Skeleton: Of the papillae, a palisade of tylostyles with an often dense spread of spirasters; of the galleries, loosely strewn tylostyles and microscleres.
Reproduction: Oocytes have been observed in September.
Ecology: Apparently confined to mollusc shells and calcareous algae, not known from dead limestone rocks. It is definitely less destructive than C . celata . Depth range is 0-1300 m.
Distribution: Scandinavia, British Isles, North Sea, west coasts of France; Western Mediterranean.
Type specimen information: The only remains left of the type are 4 slides in the Hancock Museum at Newcastle-upon-Tyne, England, reg.nrs 4.16.01-04, from Guernsey, Channel Islands (Rützler and Stone, 1986).
Remarks
This is an easily recognizable species with papillae much smaller and more densely crowded than those of Cliona celata . From C . vastifica it differs on sight by the pale yellow colour of the papillae (against the orange-red ones of vastifica ). The latter species has spined microxeas among its spicules (mircoscopic examination necessary).
Source: Topsent, 1888a.