Leucilla australiensis ( Carter, 1886 )

Leucilla australiensis ( Carter, 1886) View in CoL

Figures 69a–i View FIGURE 69

Leucilla uter Poléjaeff, 1883: 53 View in CoL (in part, only the Philippine specimen, which is not conspecific with the type from Bermuda).

Leuconia johnstonii var. australiensis Carter, 1886: 133 .

Leucilla australiensis View in CoL ; Dendy & Row, 1913: 783; Burton, 1930: 7, fig. 6; Borojevic, 1967a: 221, fig. 25.

(Not: Leucilla australiensis View in CoL ; Borojevic & Peixinho, 1976: 1031, fig. 27; nec: Leucilla uter sensu Borojevic & Boury-Esnault, 1987: 35 View in CoL (both = Leucilla sacculata ( Carter, 1890) View in CoL fide: Muricy et al. 2011: 25).

Material examined. ZMA Por. 00137, Indonesia, Maluku, Kai Islands, off Nuhu Jaan , 5.6083°S 132.92°E, depth 90 m, dredge, sandy bottom, coll. Siboga Expedition stat. 260, 16 December 1899 GoogleMaps ; ZMA Por. 00138, Indonesia, Maluku, Banda anchorage, 4.5398°S 129.9084°E, depth 9–45 m, trawled, coll. Siboga Expedition stat. 240, 22 November 1899 GoogleMaps ; ZMA Por. 16165b, Indonesia, SW Sulawesi, Samalona , 4.8747°S 119.3419°E, depth 6 m GoogleMaps , SCUBA, coll. N.J. de Voogd, # SA/200497 /06, 20 April 1997 (incorporated in a mass of Clathrina chrysea tubes) ; ZMA Por. 20719, Indonesia, Nusa Tenggara, Sumba, NE coast off Melolo , 9.9°S 120.7083°E, depth 6 m GoogleMaps , SCUBA, coll. R. W.M. van Soest, Indonesian-Dutch Snellius II Expedition stat. 048, 13 September 1984 .

Description. Thick-walled semiglobular or tubular individuals ( Fig. 69a View FIGURE 69 ), up to 2 cm in height and width. There is an atrial chamber with a naked osculum with small fringe. Surface irregular. Consistency soft. Color dirty white, in alcohol it is greyish.

Histology. Leuconoid aquiferous system ( Fig. 69b View FIGURE 69 ).

Skeleton. Inarticulate ( Fig. 69b View FIGURE 69 ).In cross section the dermal cortex, where present, is formed by small equiangular triactines, and these are carried by subcortical giant tetractines with very long unpaired actines. The choanosomal skeleton ( Fig. 69b View FIGURE 69 ) is formed primarily by the long unpaired actines of the cortical tetractines and supported by confusedly arranged giant and smaller tetractines with almost equal actines and the unpaired actines of slightly sagittal subatrial giant triactines. The atrial skeleton consists of a layer of small sagittal triactines. The thin oscular rim contains bundles of thin diactines and thinner forms of the small cortical triactines and atrial tetractines.

Spicules. ( Figs 69c–i View FIGURE 69 ) Giant tetractines and triactines, small regular triactines, small regular tetractines, sagittal tetractines, trichoxeas of the oscular rim.

Giant tetractines of the cortical skeleton ( Fig. 69c View FIGURE 69 ), strongly sagittal, unpaired actines 330– 650.4 – 1300 x 18 – 40.5 –54 µm, paired actines 320– 45.9 –660 x 19–38.3–55 µm, apical actines 42– 151.9 –330 x 20– 36.9 –55 µm.

Giant tetractines of the choanosome ( Fig. 69d View FIGURE 69 ), slightly smaller, basal triradiate system equiactinal, paired and unpaired actines 330–528 x 19–38 µm, apical actines 42–252 x 20–36 µm.

Giant triactines ( Fig. 69e View FIGURE 69 ), equiactinal, actines 384– 491.3 –690 x 18– 30.8 –42 µm

Regular equiangular tetractines ( Fig. 69f View FIGURE 69 ), actines of basal triradiate system 60– 82.2 –111 x 4– 5.8 –8 µm, apical actines small, approximately 10 µm.

Cortical small triactines ( Fig. 69g View FIGURE 69 ), equiangular or occasionally tripod-like, 78– 185.1 –298 x 4– 10.9 –19 µm.

Sagittal tetractines ( Fig. 69h View FIGURE 69 ), unpaired actines 78– 113.3 –127 x 5– 7.2 –9 µm, paired actines 57–93.2–132 x 4– 5.8 –8 µm, apical actines 20– 30.5 –39 x 3– 4.3 –6 µm.

Trichoxeas ( Fig. 69i View FIGURE 69 ) of the oscular rim,mostly broken in the slides, 60–500 x 1–2 µm.

Ecology. Occurring in a wide depth range: 6 m down to 90 m, on reefs and on sandy bottom.

Distribution. Indonesia, Philippines, South Australia, South Africa.

Remarks. Poléjaeff assigned specimens from widely divergent areas to the type series for his Leucilla uter . Burton (1963: 636) assigned lectotype status to Poléjaeff’s Bermuda specimen, whereas the Philippine specimen is the paralectotype (named ‘co-type’ by Burton). This assignment makes it clear that the name L. uter cannot be employed for our specimens. Leucilla australiensis is the next eldest name and its type locality is sufficiently close to justify us to name our material L. australiensis .

The present material conforms to Poléjaeff’s description of Leucilla ute r in most aspects (skeleton and spicule dimensions), although Poléjaeff only provides upper values of the spicule sizes. Our smaller atrial tetractines are on average considerably smaller than Poléjaeff’s data, but the upper values match. Poléjaeff fails to mention or illustrate the cortical small triactines, but these are also rare or absent in many parts of our specimens.

Burton (1930) also assigned the present specimen to L. australiensis and compared them with slides of Carter’s holotype. Although the general structure and the spicule categories appear to conform to Carter’s holotype from Port Philip Bay, South Australia, there are some compelling differences with the Indonesian specimens, such as the larger sizes of the giant tetractines and triactines, and the smaller sizes of the cortical and atrial triactines and the choanosomal tetractines. However, Carter’s description is deficient and both Dendy (1913) and Borojevic (1967a) maintain that these aspects are variable among specimens of a widely distributed L. australiensis . Burton (1963) reverted his decision to associate the present material to L. australiensis and considered it to belong to the Southeast Australian Paraleucilla saccharata ( Haeckel, 1872) (originally as Leucandra ). We will not follow this controversial decision.

Additional Indonesian Calcarea not represented in the present collections

Species reported reported from Indonesia by other authors, which do not appear to be represented in our collections, are listed here for completeness sake. Most of these records are insufficiently characterized or described.