Tedania (Tedania) brevispiculata Thiele, 1903

(Fig. 16 A–E)

Examined material. Sample HL 165: Vietnam, Hang Trai Island, Hang Du II Lake, intertidal, 26 April 2004.

Description. Massively encrusting sponge, up to 2.5 cm thick, binding several branches of Carijoa riisei (Fig. 16 A). The sponge presents a smooth but irregular surface with lobate, rounded projections. Beige in ethanol (Fig. 16 A). The sponge is broken in several fragments; the largest are about 12 cm 2.

Skeleton. The ectosomal skeleton is composed by scattered tornotes, rarely arranged in tracts. The choanosome consists of short, multispicular tracts of styles forming a loose web with numerous dispersed spicules (Fig. 16 B).

Spicules. Styles straight, often slightly curved (Fig. 16 C), 215 – (231.5 ± 7.2) – 252.5 x 5 – (8.1 ± 1.6) – 12.5 μm. Tornotes straight with spined tips (Fig. 16 D), 200 – (210.7 ± 7.1) – 229 x 2.5 – (2.75 ± 0.8) – 5 μm. Onychaetes straight or slightly curved with small spines not clearly visible with light microscopy (Fig. 16 E), 42 – (137.3 ± 37.6) – 165 μm. The smallest onychaetes, measuring ~42 μm, are not frequent.

Distribution and remarks. Ternate, Indonesia (Thiele 1903) and Vietnam (Lévi 1961; Azzini et al. 2007). This species fits with the descriptions of Thiele (1903) and Lévi (1961) who found the species in southern Vietnam. The species was described as a thin encrustation (1–2 mm tick) and with styles, tornotes and onychaetes similar in shape and size (210 x 10 μm, 170 x 6 μm, 140 x 1 μm, respectively) to those of the present specimen. SEM observations revealed the presence of small onychaetes, similar to the larger ones but that have not been previously reported. Samples were recorded at the intertidal level in a dark tunnel connecting a marine lake in Ha Long Bay to the open sea.