Perez, Perrin, Carteron, Vacelet & Boury-Esnault, 2006
Celtodoryx girardae Perez, Perrin, Carteron, Vacelet & Boury-Esnault (2006) is a pale yellow, massive to large, soft, cauliflower-shaped sponge, recently discovered in Bretagne (NW France) and the Netherlands. It is apparently an invasive species belonging to a genus that was previously unknown. Its spicular characters are unique and characteristic (microscopic preparation necessary).
Colour: pale yellow, or pale brown, not unlike certain forms of Halichondria panicea.
Shape, size, surface and consistency: Globular-massive, cauliflower-like, with irregularly lobate to honeycombed surface, occasionally with tube-like semitransparent extensions. Sizes of 10-30 cm are common, but it may be considerably larger, as specimens covering an area of up to 25 m2 are reported off the island of Tholen in the eastern region of the Oosterschelde, SW Netherlands. Consistency soft, easily damaged. Mucousy-sticky.
Spicules (Celtodoryx_spicules.jpg ): Megascleres at first glance of a single type, tylotes, but they are quite variable in thickness and ornamentation. Possibly they consist of two types, one derived from proper tylotes (thinner, shorter), 180–320 x 2–8 µm, the other from styles (thicker, longer), 260–384 x 6–12 µm, but these types do not appear to be localized. Microscleres: oxychaetes, symmetrical finely spined microscleres, ends tapering to thin points, 55–90 x 0.5-1 µm; and arcuate chelae in two distinct size categories, 23–30 µm and 45–63 µm.
Skeleton: Ectosomal skeleton a loose tangential
arrangement of single tylote/strongylote megascleres and
numerous microscleres. Choanosomal skeleton plumose or plumoreticulate, reminiscent of Tedania; megascleres form bundles of 40–150 µm in diameter fanning out towards the surface and forming a loosely connected reticulation.
Ecology: occurring in sheltered areas with strong tidal currents from 2 tot 38 m depth.
Distribution: Gulf of Morbihan (Bretagne) and Oosterschelde (SW Netherlands).
Etymology: Named after A. Girard.
Type material: Paris Museum MNHN DJV 92 and 93.
This genus and species was recently erected (Perez et al., 2006) for specimens recorded from the south of Bretagne (France) from 1996 onwards, in a well studied area from where it was previously unknown. It is likely an invader from an unknown part of the world. Very shortly afterwards, or perhaps more or less simultaneously, the species was found to occur in the Netherlands, either imported from France or from the same unknown source area. The species appears to be well established as specimens were collected in consecutive years and it is reported to have developed very large individuals in several Oosterschelde localities (Peter van Bragt, personal observation).
Sources: Perez et al. 2006; van Soest et al. 2007.