Axinella donnani ( Bowerbank, 1873 )

Pereira, Preeti & Raghunathan, Chelladurai, 2020, New records of Indo-Pacific sponges from the Andaman and Nicobar Islands India, Zootaxa 4894 (4), pp. 81-97 : 86

Axinella donnani ( Bowerbank, 1873)

( Figures 3 A–D)

Synonymy:

Isodictya donnani Bowerbank, 1873: 28 , pl. VI, figs. 2–6.

Axinella donnani ( Bowerbank, 1873) : Dendy, 1887: 158, pl. XI, fig. 1; Dendy, 1889: 89; Thomas, 1970: 207, fig. 1, 4; Thomas, 1979: 28, pl. II, fig. 3; Thomas, 1981: 29, pl. II, fig. 15, pl. IV, fig. 33; Thomas, 1985: 289.

Material examined: 2 specimens, ZSI/ANRC–17049, February 22, 2017, Natural Bridge , Neil Island, Ritchie’s Archipelago, Coll. Seepana Rajendra ; 2 specimens, ZSI/ANRC–17058, May 12, 2016, Pongibalu , South Andaman, Coll. Preeti Pereira ; 2 specimens, ZSI/ANRC–17061, November 17, 2015, Hut Bay Jetty, Little Andaman, Coll. Seepana Rajendra ; 1 specimen, ZSI/ANRC–17497, May 28, 2017, Trilby Island , North Andaman; Coll. Seepana Rajendra , 1 specimen, ZSI/ANRC–17504, May 29, 2017, Durgapur (site II), North Andaman, Coll. Naveen Kumar Nigam ; 1 specimen, ZSI/ANRC–18068, October 25, 2017, Tree Islet North Andaman , Coll. Preeti Pereira ; 1 specimen, ZSI/ANRC–19281, March 19, 2018, Bus Stop (a dive site), Neil Island, Ritchie’s Archipelago, Coll. Preeti Pereira.

Description: Massive, cup-shaped or funnel-shaped with undulating margins and thick walls, sometimes attached by a stalk to the substratum ( Fig. 3A ); Surface slightly hispid; colour bright orange when alive and lighter on preservation in iso-propyl alcohol ( Fig. 3B ); consistency compact and compressible. The sponge measured 7 cm across with a stalk length of 2 cm; ostia not visible, oscules measured 0.2 to 0.4 mm.

Skeleton: Ectosome not specialized; choanosomal skeleton made up of strong fasciculate primary fibres often branching into secondary fibres, giving it a confused appearance; spicules interspersed with clear spongin with their ends projecting beyond the ectosome, giving the sponge a lightly hispid appearance ( Fig. 3C ).

Spicules: Styles and oxeas ( Fig. 3D ).

Styles smooth, thick and slightly curved; Oxeas stout, slightly curved and sharply pointed at both ends. The spicule morphometrics varied greatly among the survey localities ( Table 2).

Distribution: Axinella donnani is reported herein for the first time from the Andaman province. The type locality of this species is Sri Lanka ( Bowerbank 1873) and subsequent records have been made from the Gulf of Mannar ( Dendy 1889; Thomas 1970; Thomas 1985) in the West and South Indian Shelf province; Tamil Nadu, Eastern India ( Dendy 1887) in the Bay of Bengal province; Tulear, Madagascar ( Vacelet & Vasseur 1977), Mahe Island Seychelles ( Thomas 1981), Mozambique Channel, Delagao ( Thomas 1979), Western and Northern Madagascar in the Western Indian Ocean province. The distribution of this species is restricted to the Western Indo-Pacific realm. Further records of this species in India include Poshetra, Gujarat ( Dendy 1916), Gulf of Kutch ( Subba Rao & Sastry 2005) and Karnataka ( Pattanayak & Mitra 2013).

Remarks: The specimens examined in the present study are similar to those described by Bowerbank (1873) and Thomas (1985). Widely distributed in the western Indo-Pacific, this species was commonly recorded from the shallow water sub-tidal localities of the Andaman group of Islands in depths ranging from 4– 20 m.

Figures

FIGURE 3. Axinella donnani (Bowebank, 1873) (ZSI/ANRC–19281): A, in situ photograph. B, preserved specimen. C, tangential view of skeleton. D, oxea and style.