Agelas ceylonica Dendy, 1905 sensu Thomas, 1981

Pereira, Preeti & Raghunathan, Chelladurai, 2020, New records of Indo-Pacific sponges from the Andaman and Nicobar Islands India, Zootaxa 4894 (4), pp. 81-97 : 84-85

Agelas ceylonica Dendy, 1905 sensu Thomas, 1981

( Figures 2 A–F)

Synonymy:

Agelas ceylonica Dendy, 1905: 175 , pl. XII, fig. 9; Lévi, 1961: 23, fig. 30, pl. 1. fig. 2; Thomas, 1980: 3, fig. 1e, f; Thomas, 1981: 20, pl. I, fig. 11, pl. II, fig. 6; Thomas, 1985: 205.

Material examined: 1 specimen, ZSI/ANRC–20437, June 15, 2018, Outram Island , Ritchie’s Archipelago, Coll. Preeti Pereira.

Description: Branching sponge with hollow tubes, growing upright from the substrate; the specimen was covered with debris so that only oscules were visible, on brushing off the sediment, bright orange, hispid surface and a thin dermal membrane was recognizable ( Fig. 2A ); the specimen turned light orange/beige after preservation ( Fig. 2B ); branches finely hispid, 7 mm in diameter; consistency soft, tough and resilient.

Skeleton: Skeleton made up of fine, pale spongin cored by acanthostyles, fibres cored; primary fibres 40–60 µm thick, echinated, secondary fibres 20–30 µm thick; meshes 100–270 µm in diameter; acanthostyles, smooth styles and styles with plain whorls, scattered in the choanosome ( Fig. 2C ).

Spicules: Verticillate acanthostyles ( Fig. 2D ), styles with smooth whorls ( Fig. 2E ) and smooth styles ( Fig. 2F ); acanthostyles 120.0–205.5–276.0 × 7.1–14.2– 19.6 µm with 14–21 spine whorls, styles with plain whorls 164.2– 194.1– 214.4 × 7.5–16.2– 12.9 µm with 14–17 smooth whorls, smooth styles 136.3–172.3–211.3 × 2.5–4.4– 6.6 µm.

Distribution: This is the first report of Agelas ceylonica sensu Thomas from the Andaman province. Its distribution was restricted to the Western Indo-Pacific realm. It has previously been reported from Sri Lanka ( Dendy 1905), South India and Sri Lanka ecoregion in the West and South India shelf province; between the Great Pass and Canal Johny, Cargados Carajos ( Lévi 1961), Mahe Island, Seychelles ( Thomas 1981) in the Western Indian Ocean province; Minicoy Island ( Thomas 1986), Maldives ecoregion in the Central Indian Ocean Islands province.

Remarks: The specimen examined from the Andaman and Nicobar Islands differs from the original description in the size of the tubes, colour and the presence of styles as an additional type of spicule. Manconi et al. (2016) summarized that the morphological characters of Agelas ceylonica are notably variable especially the growth form and colour. The specimen reported herein has a branching growth form with hollow tubes, which is similar to “slen-der, anastomosing, sub-cylindrical branches” ( Dendy 1905) and “cavernous endosome” ( Thomas 1981). The bright orange colour differs from the brown ( Dendy 1905), pale gray ( Thomas 1981), and is in agreement with the orange specimen described by Lévi (1961). The presence of smooth styles with plain whorls was not mentioned in the original description ( Dendy 1905), but found by Thomas (1981) when analysing additional specimens. As we found styles with plain whorls, the specimen reported herein is assigned to Agelas ceylonica sensu Thomas, 1981 .

Figures

FIGURE 2. Agelas ceylonica sensu Thomas, 1981 (ZSI/ANRC–20437): A, in situ photograph. B, preserved specimen. C, tangential view of the skeleton showing spongin and acanthostyles. D, acanthostyles. E, styles with plain whorls. F, smooth style.