Boring sponges from the Ha Long Bay (Tonkin Gulf, Vietnam)

Sponges of Vietnam are poorly known (Lévi 1961) particularly excavating sponges. In 1898, Lindgren recorded 20 species from Nha Trang (southern Vietnam), none of them excavating. The only paper entirely devoted to the sponge fauna of Vietnam was written by Lévi (1961), who recorded 28 species from Nha Trang, but included no excavating sponges. Excavating sponges from Vietnam were reported by Dawydoff (1952) in a paper on the Indo-Chinese marine benthic fauna, but the most complete reference regarding the area is a checklist of sponges recorded from the South China Sea by (Hooper et al. 2000). During 4 surveys performed from 2002 to 2004, 9 species of boring sponges were recorded from Ha Long Bay, on the northern coast of Vietnam: Cliona aurivilli (Lindgren 1897), C. celata Grant, 1826, C. orientalis Thiele, 1900, Cliothosa hancocki (Topsent 1888), Pione carpenteri (Hancock 1826), Spirastrella decumbens Ridley, 1884, S. solida Ridley and Dendy, 1886, S. tentorioides Dendy, 1905, and Aka mucosa (Bergquist 1965). Cliona orientalis, P. carpenteri, S. decumbens, S. tentorioides Dendy 1905, and A. mucosa are new records from the Tonkin Gulf, whereas all the other species are already known from Vietnam. The aim of this paper was to make an initial contribution to the knowledge of the Vietnamese excavating sponges in the Tonkin Gulf, northern Vietnam.