Vosmaeria Fristedt, 1885 (Porifera, Demospongiae, Halichondriidae): revision of species, phylogenetic reconstruction and evidence for split Author Gerasimova, Elena Author Erpenbeck, Dirk Author Plotkin, Alexander text Zootaxa 2008 1694 1 37 journal article 10.5281/zenodo.180677 6b8ec8f2-f45d-4239-968e-d63cee165d73 1175-5326 180677 Vosmaeria levigata Topsent, 1896 Synonymy: Vosmaeria levigata – Topsent, 1896 : 128 . Vosmaeria laevigata – Borojevic, Cabioch & Lévi, 1968 : 16 .

Type material:
Holotype: MNHN	DT	2386	(1	anatomical	slide):	vicinity	of	Roscoff,	French	Coast,	the	English	Channel;
collector E. Topsent.

FIGURE 18. Vosmaeria levigata (incertae sedis): skeleton. Scale bar for A: 0.5 mm, scale bars for B–D: 0.1 mm. A–section of the body of the holotype. B–tylostyle of the specimen MNHN DCL 916. C–oxea of the same specimen. D–oxeaderived style of the same specimen. 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). TABLE 8. Vosmaeria levigata (incertae sedis): variability of spicule shape. Number of spicules characterized by the respective feature is given in every cell.

MNHN DT 2386	MNHN DCL 916
Tylostyles Oxeas	Tylostyles Oxeas
Curvature Straight	8 9	7 3
Slightly curved	17 17	22 22
Moderately curved	5 4	1 5
Considerably curved	0 0	0 0
Slenderness Fusiform	6 30	9 30
Slender	24 0	21 0
Tyle development Absent	0 30	0 30
Weakly developed	0 0	8 0
Well developed	30 0	22 0
Tyle location Terminal	26 –	24 –
Slightly displaced	2 –	5 –
Moderately displaced	2 –	1 –
Considerably displaced	0 –	0 –

TABLE 9. Vosmaeria levigata (incertae sedis): results of spicule measurements. All measurements are given in µm. Each measurement is given as minimum-mean-maximum. MNHN DT 2386 MNHN DCL 916 Distribution:

Tylostyles	Oxeas	Tylostyles	Oxeas
Length	159-255-397	378-540-678	211-323-444	422-633-833
Proximal diameter	2.7-3.5-5.4	–	2.7-5.3-8.1	–
Central diameter	2.7-3.8-8.1	4.1-8.3-10.8	4.1-5.7-9.5	4.1-11.9-16.2

FIGURE 19. Vosmaeria levigata (incertae sedis): geographical distribution. Known only from type locality (fig. 19).