Dragmacidon australe ( Bergquist, 1970 )

Pereira, Preeti & Raghunathan, Chelladurai, 2020, New records of Indo-Pacific sponges from the Andaman and Nicobar Islands India, Zootaxa 4894 (4), pp. 81-97 : 87-89

Dragmacidon australe ( Bergquist, 1970)

( Figures 4 A–D)

Synonymy:

Pseudaxinella australis Bergquist, 1970: 20 : 20, Pl 4c, 12c.

Dragmacidon australe ( Bergquist, 1970) : Alvarez & Hooper, 2009: 27, fig. 7 C–D, 9 A–B; Alvarez, Voogd, & Van Soest, 2016: 457–459, fig. 5.

Material examined: 1 specimen, ZSI/ANRC–19927, March 19, 2018, Bus Stop, Neil Island , Ritchie’s Archipelago, Coll. Preeti Pereira.

Description: Thickly encrusting ( Fig. 4A ), 5 cm in diameter and 3 cm thick; deep red in colour when alive and

on preservation ( Fig. 4B ); consistency hard and incompressible; surface brush-like with slightly short and broad conules; oscules conspicuous; 2–4mm in diameter.

Skeleton: The skeleton is made up of thick multi-spicular tracts and forms irregular oval or circular meshes, measuring 100–400 µm in diameter ( Fig. 4C ). Primary fibres thick, measuring 50–80 µm, densely interspersed with spicules; secondary fibres sparse.

Spicules: Styles and oxeas ( Fig. 4D ).

Oxeas smooth and sharply pointed, 128.9–322.7–373.7 × 2.9–10.1–17.0 µm.

Styles thin and slightly curved, 267.6–305.2–351.3 × 4.2–7.7– 14.3 µm.

Distribution: Originally described from New Zealand, Temperate Australasia realm by Bergquist (1970), Dragmacidon australe was subsequently recorded from Northern Great Barrier Reef, Northern Australia, Cartier Island, Sahul Shelf of the Northeast Australian Shelf and Sahul Shelf provinces in the Central Indo-Pacific realm (Hooper & Levi 1993). Alvarez & Hooper (2009) extended the distribution range of this species to the Northern Australia in their revision of Axinellids and stated that it is “probably at the edge of its range”. However, its distribution was further extended towards the Western Coral Triangle and possibly to Sunda Shelf in the Central Indo-Pacific realm ( Alvarez et al. 2016). The current report confirms its extension into the Andaman province of the West Indo-Pacific realm.

Remarks: At present, Dragmacidon australe is known from a single specimen from Ritchie’s Archipelago in the Andaman Islands. This specimen examined herein was found to be very similar to the species described from New Zealand by Bergquist (1970).

Figures

FIGURE 4. Dragmacidon australe (Bergquist, 1970) (ZSI/ANRC–19927): A, in situ photograph. B, preserved specimen. C, tangential view of the skeleton. D, styles and oxeas.