Ernstia indonesiae, Van Soest & De Voogd, 2015

Ernstia indonesiae View in CoL sp. nov.

Figures 13a–c View FIGURE 13 , 14a–d View FIGURE 14 , 15a–e View FIGURE 15

? Clathrina sp. Colin & Anderson, 1995: 59, photo 228.

Material examined. Holotype ZMA Por. 16659, Indonesia, SW Sulawesi, Spermonde Archipelago, Langkai , 5.019°S 119.063°E, depth 6 m, SCUBA, coll. B.W. Hoeksema, #LK–186, 14 June 1997. GoogleMaps

Paratypes ZMA Por. 07934, Indonesia, SE Sulawesi, Tukang Besi Islands, southern reef of Karang Kaledupa , 5.9333°S 123.8°E, depth 2–6 m, snorkeling, coll. J.C. den Hartog, Indonesian-Dutch Snellius II Expedition stat. 016/II/26, 8 September 1984 GoogleMaps ; ZMA Por. 09107, Indonesia, SE Sulawesi, SW Salayar, NW coast of Pulau Guang , 6.35°S 120.45°E, depth 0–2 m, snorkeling, coll GoogleMaps . R. W.M. van Soest, Indonesian-Dutch Snellius II Expedition stat. 152/ Cave 2/02, 28 September 1984 ; ZMA Por. 09486, Indonesia, SE Sulawesi, SW Salayar, NW coast of Pulau Guang , 6.35°S, 120.45°E, depth 2–4 m GoogleMaps , SCUBA, coll. R. W.M. van Soest, Indonesian-Dutch Snellius II Expedition stat. 152/ Cave 1/06A, 28 September 1984 ; ZMA Por. 15509c, Indonesia, SE Sulawesi, SW Salayar, NW coast of Pulau Guang , 6.35°S 120.45°E, depth 3–4 m GoogleMaps , SCUBA, H.A. ten Hove, Indonesian-Dutch Snellius II Expedition stat. 152/ Cave 1/A3, 28 September 1984 .

Description. Rounded mass of interwoven tubes ( Fig. 13a View FIGURE 13 ), individual tubes 1–3 mm in diameter. In the one in situ photo several oscules at the end of water-collecting tubes are apparent but these are not visible in the preserved material ( Figs 13b View FIGURE 13 , 15a View FIGURE 15 ). Live color pinkish white, in alcohol pale orange. Overall size of specimens up to 5 x 4.5 x 2 cm.

Skeleton. ( Figs 13c View FIGURE 13 , 15b View FIGURE 15 ) Walls of tubes formed by a one or two layers of triactines and tetractines arranged without apparent order.

Spicules. ( Figs 14a–d View FIGURE 14 , 15c–e View FIGURE 15 ) Triactines, tetractines, diactines.

Triactines ( Figs 14a View FIGURE 14 , 15d View FIGURE 15 ), equiangular equiactinal, in a large size range, but no clear division in larger and smaller categories, 90– 206.7 –269 x 10– 17.3 –22 µm

Tetractines ( Figs 14b–d View FIGURE 14 , 15c View FIGURE 15 ), less diverse in size, but divisible into those with regular equiangular equiactinal basal radiate systems, actines 85– 214.2 –249 x 12– 17.8 –22 µm, apical actines long and sometimes wavy, 57– 124.1 –204 x 6– 10.7 –14 µm; and parasagittal tetractines with unpaired actines, straight, 198–210 x 12–14 µm, paired actines usually curved or wavy, 137–159 x 12–14 µm, apical actines 50–60 x 10 µm.

Diactines ( Fig. 15e View FIGURE 15 ), uncommon, curved, usually with one end thicker and mucronate, ( Fig. 15e View FIGURE 15 1 View FIGURE 1 ) the other end tapering gradually into a thin straight or curved ending, usually broken into fragments, 200– 345 –600 x 2– 4.6 – 9 µm.

Ecology. Reefs, shallow depth.

Distribution. Indonesia.

Etymology. Named after the country Indonesia.

Remarks. In the key of Klautau & Valentine (2003), this material keys out as the Japanese Clathrina sagamiana ( Hôzawa, 1929) (p. 281, pl. XIII figs 1–2, textfig. 1), assigned to Ernstia in Klautau et al. 2013. There are considerable differences between E. sagamiana and our specimens: the triactines of the former are smaller, the apical actines of the tetractines are longer, and the diactines are also longer. Parasagittal tetractines were not mentioned by Hôzawa. A further problem is that our material is all from shallow-water reefs and reef caves, whereas the Japanese material was collected at 171 m depth.

It is likely that our specimens are conspecific with Clathrina sp. sensu Colin & Arneson (1996: photo 228) from Papua New Guinea.