Clathrina repens, Van & De, 2018

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 52

Clathrina repens sp.nov.

Figures 26a–d

Material examined. Holotype, RMNH Por. 10161a, Maldives, Faafu Atoll, Wallstreet, 3.119°N 72.979556°E, depth 10 m, scuba, coll. N.J. de Voogd, field nr. MAD10 /MAS122, 20 February 2015.

Description. Open network of creeping and upright tubuli, covering the surface of a keratose sponge ( Hyrtios sp.) ( Fig. 26a ), size several cm2. A second specimen ( Fig. 26a 1 , not collected) encrusted an ascidian. Individual tubuli approximately 2 mm high and 1 mm diameter. Upright tubuli often open-ended, presumed to be oscules. Color shades of dull orange, pink-orange and beige; pale beige in preservation ( Fig. 26b ).

Aquiferous system. Asconoid.

Skeleton. ( Fig. 26c ) Walls of tubuli with a single layer of spicules.

Spicules. ( Fig. 26d ) Triactines with conical actines, variable in length, 66– 97 –129 x 6 – 7.4 –9 µm.

Distribution and ecology. Maldives, coral reef, 10 m.

Etymology. Repens (L.) means creeping, referring to the reticulation of small tubuli closely adhering to the substratum.

Remarks. Morphologically, this appears a unique species. Its habitus and spicule sizes show similarity to Indonesian Arturia tubuloreticulata Van Soest & De Voogd, 2015 , but this has a minority of tetractines. We examined the present specimen exhaustively, but could find no tetractines.

Unfortunately, no sequences were obtained from it.

Figures

FIGURE 1. Marine Ecoregions in the Western Indian Ocean with localities (numbered blue squares) from where the studied calcareous sponges were obtained. 1, Israelian Red Sea, Gulf of Aqaba, 2, Saudi Arabian Red Sea, off Jeddah, 3, Eritrean Red Sea, Dahlak Archipelago, 4, Oman, Gulf of Arabia, 5, Maldives, 6, India, Lakshadweep, 7, Seychelles, Mahé region, 8, Seychelles, Amirantes, 9, Mayotte, 10, Mozambique Channel, 11, Mauritius, 12, Rodrigues, 13, South Africa, Kwazulu Natal, 14. South Africa, Port Elizabeth, 15. Nosy Be, Madagascar.

FIGURE 26. Clathrina repens sp.nov., a, in situ habitus of holotype RMNH Por. 10161 from the Maldives, a1, in situ habitus of a second specimen (not collected) (photos N.J. de Voogd), b, preserved holotype (scale bar = 1 cm), c, light microscopic image of one of the tubuli, d, SEM images of the spicules.