Vosmaeria levigata Topsent, 1896

Gerasimova, Elena, Erpenbeck, Dirk & Plotkin, Alexander, 2008, Vosmaeria Fristedt, 1885 (Porifera, Demospongiae, Halichondriidae): revision of species, phylogenetic reconstruction and evidence for split, Zootaxa 1694, pp. 1-37 : 28-31

Vosmaeria levigata Topsent, 1896

Synonymy:

Vosmaeria levigata – Topsent, 1896: 128. Vosmaeria laevigata – Borojevic, Cabioch & Lévi, 1968: 16.

Additional material:

MNHN DCL 916 (1 spicule slide): same locality as holotype; collector C. Lévi.

Description:

External characters

Sponges small, smooth, yellowish crusts on stones and pebbles ( Topsent, 1896; Borojevic et al., 1968).

Skeleton

Skeleton constituted by (sub)tylostyles and oxeas is disordered and confused over the whole body ( Topsent, 1896). The slide of Topsent represents several hand-made sections with a confused spicule mass and residuals of soft body (fig. 18A). The skeleton arrangement can hardly be observed. It is also unclear if there is a special ectosomal skeleton or not.

Spicules (means in parentheses)

-(Sub)tylostyles: 30 spicules were measured on each slide. All tylostyles with acerate distal tips (fig. 18B). Most of them slightly curved, slender and with terminal tyles (table 8). In both examined specimens several tylostyles with lobate tyles, which had also been noted by Topsent (1896). In the holotype the tyles of all tylostyles well developed while in the specimen of Lévi eight subtylostyles with weakly developed tyles. Altogether, tylostyles measure 159–444 µm (289 µm) in length, 2.7–8.1 µm (4.4 µm) in proximal diameter with tyle diameter of 5.4–10.8 µm (6.6 µm) and 2.7–9.5 µm (4.8 µm) in central diameter. Tylostyles of the holotype significantly shorter than those of the second specimen (table 9; df =58, T =3.94, P =0.0002).

-Oxeas: 30 spicules were measured on each slide. Oxeas usually slightly curved and with acerate tips (table 8, fig. 18C). Few oxea-derived styles observed in both specimens (fig. 18D). Altogether, oxeas measure 378–833 µm (mean 586 µm) in length and 4.1–16.2 µm (mean 10.1 µm) in central diameter. Oxeas of the holotype significantly shorter than those of the second specimen (table 9; df =57, T =3.79, P =0.0004).

Number of spicules characterized by the respective feature is given in every cell.

All measurements are given in µm. Each measurement is given as minimum-mean-maximum.

MNHN DT 2386 MNHN DCL 916 Distribution:

Known only from type locality (fig. 19).