Batzella fusca, Van, Rob W. M., 2009

Van, Rob W. M., 2009, New sciophilous sponges from the Caribbean (Porifera: Demospongiae), Zootaxa 2107, pp. 1-40 : 19-20

Batzella fusca n. sp.

( Figs 7 A–C)

Holotype. ZMA Por. 21064, Bonaire, Karpata, 12.222°N - 68.351°W, under rubble, 5 m, 1987, coll. H.G.J. Pennartz #5.

Additonal material (not belonging to the type series). Bonaire, Karpata, 12.222°N - 68.351°W, under rubble, 5 m (2 specimens); Bonaire, Punt Vierkant, 12.116°N - 68.295°W, under rubble, 5 m (2 specimens); Bonaire, Red Slave, 12.034°N - 68.259°W, under rubble, 5 m; all observed by H.G.J. Pennartz & G.J. Roebers.

Description. Thin smooth crust, size 4 x 3.5 cm, thickness less than 0.5 mm ( Fig. 7 C). Color dark brown with purple veins; interiorly the sponge is orange–brown. Pigment grains in the lighter parts of the surface form areolae-like formations of approx. 100 µm in diameter. Consistency soft.

Skeleton. Feebly developed bundles of megascleres traverse the choanosome vertically ending at and pushing up the surface to cause microconules. No tangential surface skeleton.

Spicules. Strongyles only, no further spicules.

Strongyles ( Figs 7 A–B), straight, isodiametric, with evenly rounded (not swollen) apices, often with wide axial cavity, 213- 252.7 -277 x 3 - 3.9 -4.5 µm.

Ecology. Under coral rubble at 5 m

Etymology. Fusca (Latin) = brown.

Remarks. The mottled aspect of the surface reminds of specimens of Strongylodesma Lévi (1969) (see e.g. Samaai et al. 2004), so it was carefully verified whether the strongyles were also arranged tangentially as is the case in species of Strongylodesma . However, strongyles were only found in choanosomal bundles perpendicular to the surface, which consisted only of an organic membrane. One other species is known from the Central West Atlantic, B. rosea van Soest (1984), differing from the new species in color (rosy red) and presence of characteristic looped malformations of the strongyles found in that species. B. rosea was also observed to occur under Bonaire rubble stones (Pennartz & Roebers, unpubl. data) and could be easily distinguished from the new species. Strongylacidon bermudae (de Laubenfels, 1950 as Fibulia ), having strongyles of 180–200 µm and lacking microscleres, in addition to being dark colored, may be reminiscent of the new species, but it is a large species with tubes of 12 cm height, quite unlike the thin encrustation described here (cf. Rützler, 1986). The strongyles are also neatly smaller than Batzella fusca n. sp. and B. rosea , without overlap.

The Batzella species of the Central West Atlantic are keyed out along with the species of the genus Strongylacidon in a key presented below.

Figures

FIGURE 7. Batzella fusca n. sp., SEM images of spicules (Holotype ZMA Por. 21064). A – B. Strongyle and details of apices; C. photo of holotype encrusting a piece of coral.