Ernstia chrysops, Van Soest & De Voogd, 2015

Ernstia chrysops sp. nov.

Figures 16a–c View FIGURE 16 , 17a–e View FIGURE 17

? Clathrina sp. Gosliner et al. 1996: 15, photo 1.

Material examined. Holotype RMNH Por. 1773, Indonesia, North Sulawesi, Manddin , between Bunaken and Manado Tua, 1.612°N 124.7322°E, depth 20 m, SCUBA, coll. N.J. de Voogd, # MD04 /180502/092, 18 May 2002. GoogleMaps

Description. Mass of loosely anastomosed golden yellow tubes ( Figs 16a–c View FIGURE 16 ) with few but prominent water-collecting tubes ( Figs 16a–b View FIGURE 16 ) some of which protrude 1 cm or more above the cormus. Size of cormus up to 5 x 6 x 1 cm. Individual tubes up to 5 mm in diameter. Oscules about as wide as the tubes ( Fig. 16c View FIGURE 16 ), not flaring. In preserved condition ( Fig. 17a View FIGURE 17 ) oscules are not clearly visible and the specimens get a pale yellowish orange color and have a ‘glassy’ outlook. Consistency soft.

Skeleton. ( Fig. 17b View FIGURE 17 ) The walls of the tubes have a thin layer of triactines and tetractines, in equal proportion, with apical actines of the larger tetractines projecting into the lumen of the tubes.

Spicules. ( Figs 17c–e View FIGURE 17 ) Triactines, tetractines; a few small diactines were found.

Triactines ( Fig. 17c View FIGURE 17 ) equiangular equiactinal, in a large size range, possibly divisible in smaller and larger, overall actine sizes 75– 210.3 –330 x 9– 13.8 –18 µm (smaller ( Fig. 17c View FIGURE 17 1 View FIGURE 1 ): 75–213 µm, larger ( Fig. 17c View FIGURE 17 ): 255–330 µm); occasionally a triactine occurs with one of the actines angularly bent.

Tetractines ( Fig. 17d View FIGURE 17 ), regular, on average larger than the triactines, likewise possibly divisible in smaller and larger spicules, overall the upper sizes somewhat larger than the triactines, with actines of the basal triradiate system 186– 362.4 –661 x 14– 25.5 –48 µm (smaller: Fig. 17d View FIGURE 17 1 View FIGURE 1 ): 186–276 µm, larger ( Fig. 17d View FIGURE 17 ): 300–661 µm), apical actines straight or more often curved ( Fig. 17e View FIGURE 17 ), 18– 45.9 –122 x 4– 10.1 –18 µm.

Ecology. Deeper part of the reef.

Distribution. Indonesia; probably Philippines.

Etymology. The word chrysops (Gr.) means shining like gold, referring to the color.

Remarks. This species is close to Ernstia indonesiae sp.nov. in shape, but the color and the large size range in smaller and larger spicules with upper size of the tetractines to reach 660 µm, the relatively wider tubes, which have a ‘glassy’ outlook (preserved material), and the absence of diactines together appear solid indications of distinctness. It is likely that the Philippine Clathrina sp. (photo 1) of Gosliner et al. 1996 belongs to the present species.

Our collection also contained a flimsy fragment from deep water (240 m) off the coast of Sumba (ZMA Por. 09219, coll. Indonesian-Dutch Snellius II Expedition stat. 60), resembling in skeletal and spicular characters the present new species: tetractines with basal triradiate system having actines up to 350 x 12 µm and strongly upcurved apical actines of approximately 100 µm, triactines on average smaller than the tetractines. In view of the depth and the tiny size we hesitatingly assign this specimen to the present species.