(Topsent, 1891a)
Species Overview
Batzella inops (Topsent, 1891a) is a thinly encrusting, smooth, soft sponge with a yellow colour. It has a very simple skeleton of thin strongyles arranged in ill-defined plumose bundles. Its larvae have been described as big, yellow and having a bare posterior pole. In Western Europe this ill-known species is recorded only from the coast of Bretagne, but several records of dubious value are known from the Mediterranean.
Taxonomic Description
Colour: Yellow (Mediterranean records mention carmine red colour).
Shape, size surface and consistency: According to the original description, it is thinly encrusting, smooth and soft. No other particulars are known.
Spicules: Strongyles only. They measure 170-200 by 2-3 µm (n=25) (a slide made from the type was studied), they are isodiametric, in general equally shaped at both apices, but a few may be found with one end somewhat mucronate. There is very little variation in length and thickness and all belong obviously to a single category. Most have a wide axial canal.
Skeleton: The spicule bundles in the microscopic slide of the type are vague, not visibly bound by spongin, and they follow a wispy course. There are no obvious bouquets at the surface (but these were reported by Topsent), and an ectosomal cover of spicules is not apparent.
Reproduction: August-September. Its larvae have been described as big, yellow and having a bare posterior pole (Topsent, 1894), which is characteristic of Poecilosclerida.
Ecology: Occurring rather commonly ("assez fréquente") under stones in the mid-littoral.
Distribution: Known with certainty only from Roscoff, but recorded from various localities in the Mediterranean.
Etymology: Inops (Latin) = weak, referring to the consistency.
Type specimen information: The type is in the Paris Museum, MNHN-L.B.I.M. DT. 2109, Ile Verte, Roscoff, France.
Remarks
This species, originally described as Halichondria inops Topsent (1891), is the type of the genus Batzella Topsent (1894). Sponges similar to the type description are recorded from all over the world.
Topsent (1928b) described Mediterranean specimens of B . inops with different colour (brilliant carmine red), with larger spicules and with distinctly anisodiametric apices verging towards styles. Because of the apparent possession of both pure strongyles and anisostrongyles, he associated the genus Batzella with Desmacidon columella Bowerbank, later made type of the genus Hemimycale . Topsent also discussed the similarity of B . inops to the common Mediterranean Crambe crambe . Later authors, e.g. Sarà (1958), Arroyo et al. (1976), and Pulitzer-Finali (1978), assigned specimens to B . inops , with strongyles and styles in widely varying sizes and shapes. In view of the great variability of Crambe crambe it is likely that some of the records of B . inops were in fact that species.
A second European Batzella species is described from the Mediterranean, B . friabilis Pulitzer-Finali (1978). It possesses two categories of spicules, short and fat strongyles and long and thin “strongylotornotes”. Through this differentiation it also approaches reduced Crambe crambe .
The family assigment of Batzella is problematic. Topsent (1894, 1928) thought it belonged to the family Desmacididae (as Desmacidonidae). Many later authors (e.g. Pulitzer-Finali, 1978) reporting on Mediterranean Batzella considered it to belong to the Halichondrida, family Hymeniacidonidae. Recent authors (Van Soest, 1984; Wiedenmayer, 1989; Hooper and Wiedenmayer, 1994) allocate the genus to the Poecilosclerida, family Desmacididae. Unfortunately, that family is a dustbin (cf. Hajdu et al., 1994), and a reassignment is inevitable. The poecilosclerid nature of Batzella is derived from its apparent similarity to Strongylacidon (a genus with chelas and/or sigmas) and “sand sponges” of the genus Phoriospongia .
For further discussions on Batzella cf. Van Soest et al., 1996.
Source: Van Soest et al., 1996.