Leucandra pulvinar ( Haeckel, 1872 )

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 95-96

Leucandra pulvinar ( Haeckel, 1872)

Figs 56a–d , 57a–e

Sycolepis pulvinar Haeckel, 1870: 251 (nomen nudum)

Mlea dohrnii Miklucho-Maclay MS in Haeckel, 1872: 162 (nomen nudum)

Leucortis pulvinar var. semitica Haeckel, 1872: 163

Leucandra pulvinar ; Dendy 1905: 234 (listed, not described)

Material examined. ZMA Por. 13423, Israel, Stylus Pinnacle , Gulf of Aqaba, depth 9 m, scuba, coll. M. Wunsch, field nr. AQ 77, 6 July 1998 ; ZMA Por. 13615, Israel, NW of harbor, Gulf of Aqaba, under overhang on harbor pile, depth 12 m, scuba, coll. M. Wunsch, field nr. AQ 39, 3 July 1998.

Description. Whitish or pale yellow globular-lobate sponges ( Figs 56a,d ) with optically smooth or irregular hispid surface, approximately 3 x 2 x 1.5 cm. Both specimens have two prominent oscules, 3–4 mm in diameter, with naked collar, leading to atrial spaces that are shallow and narrow. In preserved condition the color is beigedirty white ( Fig. 56b ). Consistency brittle, firm.

Aquiferous system. Leuconoid.

Skeleton ( Fig. 56c ). A thin cortical skeleton of sagittal triactines covering tangential giant diactines arranged in all directions. There are also tangential trichoxeas. Choanosomal skeleton a confused mass of irregular triactines with scattered diactines of all sizes. Atrial skeleton consists of small irregular triactines.

Spicules ( Figs 57a–e ). Diactines, trichoxeas, sagittal triactines, irregular triactines. No tetractines.

Diactines fusiform ( Figs 57a,a 1 ), varying in size from giant to very small, 105– 929 – 2760 x 11 – 47 –108 µm.

Trichoxeas ( Figs 57b,b 1 ), often broken, but also varying in length, 123– 465 – 1200 x 1.5– 3.4 –7 µm.

Cortical triactines ( Fig. 57c ), predominantly sagittal, almost T-shaped, with unpaired actine shorter than paired actines, although equiactinal spicules also occur, unpaired actines 90– 143 –212 x 9 – 14.7 –20 µm, paired actines 165– 198 –270 x 14 – 16.3 –21 µm.

Choanosomal triactines ( Fig. 57d ), basically equiactinal, but irregularly sagittal or oxhorns-haped, 168– 229 –298 x 15 – 19.1 –24 µm.

Atrial triactines ( Fig. 62e ), smaller than the other triactines, equiactinal, irregularly parasagittal, 45– 91 –120 x 5 – 8.1 –10 µm.

Distribution and ecology. Red Sea, Sri Lanka, shallow reef localities.

Remarks. Our specimens resemble Haeckel’s 1872 description (vol. 2: 163) and figures (vol. 3: pl. 29 figs 1–10) of Leucortis pulvinar var. semitica . Next to this variety, Haeckel also described a var. indica . Since he did not describe a typical, separate variety one of the two varieties ( semitica or indica ) has to be the nominotypical variety (ICZN art. 47) Leucortis pulvinar var. pulvinar . In the absence of previous treatments of this problem, we choose here the var. semitica as the nominotypical variety to take the name pulvinar , as it is the first mentioned. It is likely that both varieties belong to the same species, but a formal synonymization must await the description of recent Indian material. Dendy’s (1905) Sri Lanka record of Leucandra (Leucortis) pulvinar remains undescribed.

There are several Leucandra species described in the region with similar spiculation, including giant diactines: Leucandra echinata Schuffner, 1877 (also reported by Dendy 1913), Leucandra fascigera Schuffner, 1877 , Leucandra donnani var. tenuiradiata Dendy, 1916 , Leucandra dwarkaensis Dendy, 1916 and Leucandra seychellensis Hozawa, 1940 ), but all these have atrial tetractines and differ in habitus. This also applies to two Leucandra species from NE Australia, L. sphaeracella Wörheide & Hooper, 2003 , and L. nicolae Wörheide & Hooper, 2003 .

Unfortunately, our attempt to obtain a partial 28S sequence failed.

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 56. Leucandra pulvinar (Haeckel, 1872), from Gulf of Aqaba, Red Sea, a, habitus in situ of ZMA Por. 13423 (photo M. Wunsch), b, preserved habitus of the same (scale bar = 1 cm), c, view of surface skeleton of the same, d, habitus in situ of ZMA Por. 13615 (photo M. Wunsch).

FIGURE 57. Leucandra pulvinar (Haeckel, 1872), ZMA Por. 13423, from Gulf of Aqaba, Red Sea, SEM images of spicules, a, giant diactines, a1, detail of sharp end of giant diactine, b, trichoxea, b1, detail of same, c, cortical triactine, d, choanosomal triactine, e, atrial triactine.

FIGURE 62. Leucandrilla aff. intermedia (Row, 1909), ZMA Por. 13482, from Gulf of Aqaba, a, habitus in situ (photo M. Wunsch), b, preserved habitus of same (scale bar = 1 cm), c, light microscopic view of peripheral skeleton.