Ulosa stuposa (Esper, 1794)

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 : 14-16

Ulosa stuposa (Esper, 1794)

Fig. 7

For synonymy, see Van Soest 1987.

Material examined

ZMA Por. 06567, Mauritania, off Cap Blanc, depth 15 m, bottom muddy, coll. R.W.M. Van Soest & J.J. Vermeulen, Mauritania II Exped. Stat. 006/01, 20.8167°N 17.0167°W, 1.2 m Agassiz trawl, 7 Jun. 1988. ZMA Por. 06705, Mauritania, SW of Cap Timiris, depth 12-18 m, bottom sand overlying limestone ridge, coll. R.W.M. Van Soest & J.J. Vermeulen, Mauritania II Exped. Stat. 049/18, 19.0833°N 16.4167°W, rectangular dredge, 11 Jun. 1988. ZMA Por. 06714, Mauritania, SW of Cap Timiris, bottom muddy sand, depth 30 m, coll. R.W.M. Van Soest & J.J. Vermeulen, Mauritania II Exped. Stat. 053/05, 19.0833°N 16.4667°W, 2.4 m Agassiz trawl, 11 Jun. 1988. ZMA Por. 06766, Mauritania, off Banc d’Arguin, bottom muddy sand, depth 48-52 m, coll. R.W.M. Van Soest & J.J. Vermeulen, Mauritania II Exped. Stat. 072/06, 20.0°N 17.4°W, 3.5 m Agassiz trawl, 13 Jun. 1988. ZMA Por. 06859, Mauritania, off Banc d’Arguin, bottom muddy sand, depth 50 m, coll. R.W.M. Van Soest & J.J. Vermeulen, Mauritania II Exped. Stat. 137/01, 20.7167°N 17.35°W, 2.4 m Agassiz trawl, 21 Jun. 1988.

Examined for comparison

ZMA Por. 09932, Portugal, Algarve, E of Sagres, 37.0°N 8.9333°W, growing on Cystoseira alga, coll. J.H. Stock, 14 Aug. 1976. ZMA Por. 16490, France, Bretagne, Roscoff, Le Taureau, depth 25 m, 48.6633°N 3.8833°W, coll. M.J. de Kluijver, Jul. 1992.

Ulosa digitata sensu Burton 1956 , slide made from a specimen in the collections of the Zoological Museum of Copenhagen collected by the Atlantide Expedition Stat. 147, 09.4333°N 14.9667°W, depth 45 m, bottom shells and forams, 14 Apr. 1946.

Description

Long branches ( Fig. 7A ) issuing from a basal mass (presumably buried in the sand), dividing sparingly, surface irregularly conulose. Length of branches up to 10 cm, diameter 0.5-1.5 cm. Consistency soft, easily damaged.

COLOUR. Variously reported as yellow, light brown, brown, blue-green or greyish. SKELETON. ( Fig. 7B ) A rectangular reticulation of thick spicule tracts, cemented by only little spongin, which is usually not visible. Tracts divisible in slightly thicker longitudinals of 35-100 µm thickness with a core of up to 15 spicules, and thinner interconnecting tracts of 30-60 µm thickness with a core of 2-10 spicules. Meshes formed by the tracts of widely divergent sizes 200-750 µm. Loose spicules are observed among the tracts, but these are absent or rare in many specimens, which appear to be ‘macerated’, possibly due to loss of tissue during alcohol preservation.

SPICULES. ( Fig. 7C, C 1 ) Styles only (no oxeote modifications were observed), sharply pointed, tending to be thicker in the middle than at the rounded end (‘fusiform’), occasionally faintly ‘centrotylote’, of rather variable size in the various specimens, but with limited variation within a specimen, 123- 161.2 - 192 x 4- 7.6 - 11 µm.

Distribution and ecology

Mauritania, Cap Blanc, Banc d’Arguin and Cap Timiris, in sandy substrate at 12-52 m ( Fig. 1 , locs. 1-3). Elsewhere, widespread from the British Isles southward, Mediterranean, Lusitanian region, Atlantic islands; southernmost record Gulf of Guinea (see below).

Remarks

The West African material shows a range of growth forms including massively encrusting and branchingerect, in accordance with the variability elsewhere. Colours in Mauritanian specimens appear duller (mostly brownish) than in Western European material (cf. Van Soest et al. 2000) and spicule thickness on average appears greater than in northern specimens: in two specimens from Western France (ZMA Por. 16490) and Portugal (ZMA Por. 09932), examined for comparison, spicules measured 140-165 x 2-6 µm. Nevertheless, there is overlap in these characters and conspecificity seems likely.

Burton (1956) reported this species (as U. digitata ) from Conakry, Guinea (9.4667°N 14.9667°W). It was described as forming a bush with branches 5-6 cm long and 0.5 cm thick. The skeleton is similar to Western European specimens and spicules conform as well (130-145 x 3-5 µm). Apparently, the distribution of U. stuposa extends over much of the coastal waters of the Northeast Atlantic.

A littoral species from Faial, Azores, Ulosa jullieni (Topsent, 1892) (1892: 137, pl. I, fig. 12, as Stylinos ), has similar skeleton with slightly smaller spicules (120-130 µm), but differs from U. stuposa primarily in growth form and surface (thickly encrusting with smooth surface and slightly elevated oscules). It is also recorded here from the piles of the pier of Villa Baleira, Porto Santo, 33.0562°N 16.334°W (ZMA Por. 21503, coll. R.W.M. Van Soest, 30 June 1990).

Figures

Fig. 7. Ulosa stuposa (Esper, 1794), ZMA Por. 06766. A. Fragmented habit. 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.