Ulosa capblancensis, Van Soest, Rob W. M., Beglinger, Elly J. & de Voogd, Nicole J., 2012

Van Soest, Rob W. M., Beglinger, Elly J. & de Voogd, Nicole J., 2012, Sponges of the family Esperiopsidae (Demospongiae, Poecilosclerida) from Northwest Africa, with the descriptions of four new species, European Journal of Taxonomy 18, pp. 1-21 : 16-18

Ulosa capblancensis sp. nov.

Fig. 8

Etymology

Named after the type locality, Cap Blanc.

Material examined

Holotype

ZMA Por. 09959 , Mauritania, off Cap Blanc , depth 11-35 m, coll. F.P. Vermeulen, 20.7°N 17.1667°W, 1906.

Description

Erect branches issue from a basal mass ( Fig. 8A ), which was presumable buried in the sandy substrate.

Individual branches 8 mm diameter at the base tapering to blunt endings of 2 to 4 mm diameter. Individual

branches up to 10 cm long. Basal mass ( Fig. 8A 1 ) 3-6 cm thick, 4-5 cm in lateral expansion. Surface of basal mass and branches roughly conulose and porose, consistency rather firm, but soft to the touch. No

apparent oscules. Possibly the specimen is somewhat macerated.

COLOUR. Brownish red in alcohol, live colour unknown.

SKELETON. ( Fig. 8B ) Forms a spongin-rich irregular reticulation with longitudinal meshes. Emphasis of the skeleton is on ascending fibres, which are cored by 2-9 spicules, whereas cross connections are predominantly cored by single spicules at widely differing angles, occasionally two or more spicules are in the connecting spongin-fibres but then these are not aligned. Meshes average 500 µm in length,

distance between longitudinal fibres is 200-400 µm, fibres have a thickness of 100-220 µm depending not only on the amount of coring but also on spongin development.

SPICULES. Robust styles only.

STYLES ( FIG. 8C, C 1 ) straight or slightly curved, isodiametrical over much of their length with sharply pointed endings, 648- 725.9 -843 x 18- 22.1 - 26 µm.

Distribution and ecology

Mauritania, on sandy platform off Cap Blanc, 10-35 m ( Fig. 1 , loc. 1).

Remarks

The growth form of the new species is similar in most respects to Ulosa stuposa , which was found in the same habitat. It is likely that colours differ (yellow-orange in typical U. stuposa , possibly red or redbrown in U. capblancensis sp. nov.). However, the major distinguishing features are (1) the structure of the skeleton, with weakly developed connecting fibres and thick irregular spongin-encased ascending spicule tracts, and (2) the relatively long and thick styles, on average twice or thrice as long and thick as those of U. stuposa (725 vs. 160 µm).

The present species might easily be confused with a local species of Dictyonella Schmidt, 1868 [possibly identical or close to Dictyonella pelligera (Schmidt, 1864) ], which shares possession of erect branches and long thick styles with U. capblancensis sp. nov. Differences are pointed surface projections, the plumose arrangement of the spicules, and the characteristic abundance of cells with refractile granules (see Rütlzer et al. 2003) of the Dictyonella species.

Figures

Fig. 8. Ulosa capblancensis sp. nov., Holotype ZMA Por. 09959. A. Habit. A1. Detail of basal mass. B. Cross section of skeleton. C. SEM image of style. C1. Detail of apices.

Fig. 1. Map of Northwest Africa, showing the approximate localities from which the sponges were collected. 1. Mauritania, Cap Blanc. 2. Mauritania, Banc d’Arguin. 3. Mauritania, SW of Cap Timiris 4. Cape Verde Islands, São Vicente 5. Cape Verde Islands, Ilheu de Cima.