Haliclona (Flagellia) hamata ( Thiele, 1903 ) Van Soest, 2017

Van Soest, Rob W. M., 2017, Flagellia, a new subgenus of Haliclona (Porifera, Haplosclerida), European Journal of Taxonomy 351, pp. 1-48 : 13-16

Haliclona (Flagellia) hamata ( Thiele, 1903) subgen. et comb. nov.

Figs 6–8

Gelliodes hamata Thiele, 1903: 942 , fig. 7.

Material examined

INDONESIA: fragment of holotype, Halmahera, Ternate, shallow depth (SMF 1640); Papua, Aru Islands, Pearl Banks , anchorage off Pulu Jedan , 5.4134° S, 134.6677° E, 13 m depth, trawl, coll. Siboga Exped . stat. 273, 23 Dec. 1899 ( ZMA Por. 03041); Nusa Tenggara, NE coast of Sumba , 9.95° S, 120.8° E, 50 m depth, coll. R. W.M. Van Soest, Agassiz trawl, Snellius II Exped . stat. 068/ V/16, 16 Sep. 1984 ( ZMA Por. 09050a); Nusa Tenggara, NE coast of Sumba , 9.95° S, 120.8° E, 50 m depth, coll. R. W.M. Van Soest, dredge, Snellius II Exped . stat. 068/ V/12, 16 Sep. 1984 ( ZMA Por. 09285).

Description

From a thickly encrusting base, the sponge issues upright branches, which may divide higher up. In the holotype these finger-shaped digitations are 2–2.5 × 0.7 cm in size ( Thiele 1903), in ZMA 09285 ( Fig. 7 ) the branches are up to 13 cm long and 1 cm in diameter, in ZMA Por. 09050a there are only lumpy fragments. The color is light brown or yellow-brown, both in situ and in alcohol. Surface optically smooth, with a few flush oscules of about 3 mm in diameter. There are encrusting bryozoans and hydroids (the holotype is described as bearing small stones and other foreign particles). Consistency firm.

SKELETON. Spongin encased fibers cored by one or mores oxeas are common, especially in the superficial region. Overall skeletal structure is a confused reticulation. Microscleres are relatively rare.

OXEAS ( Figs 6 A–A1, 8A–A1). Curved, fusiform, robust, sharply pointed, 264– 343 –425 × 13– 18. 1 – 24 μm.

FLAGELLOSIGMAS ( Figs 6 B–C, 8B–C). Predominantly circular to ovoid, with the long ending sharply curved and long-upturned, the short ending with narrow curve, in a single size range. Length of long-

ending 64– 103 –130 μm (holotype: 64–110 μm), length of short ending 40– 76 –96 μm (holotype 40– 81 μm), width 44– 89 –108 μm (holotype 44–95 μm), thickness 2– 2. 8 –4 μm (holotype 2–3.5 μm).

NORMAL SIGMAS ( Figs 6D , 8D ). Small, robust, in a limited size range, 15– 26. 1 –39 × 1.5– 2. 3 –3 μm (holotype: 15–33 × 2–2.5 μm).

Distribution and ecology

Indonesia: Ternate, Aru Islands, Sumba (Marine Ecoregions Halmahera, Arafura Sea and Lesser Sunda), on reefs and sand bottoms, shallow water down to 50 m depth.

Remarks

As discussed above, this species is distinguished primarily by a digitate-arborescent habitus from the very similar but plate-like morphology of H. (F.) indonesiae sp. nov. The flagellosigmas of the present species are also subtly larger and thicker than those of the new species; the normal sigmas are distinctly more robust.

Figures

Fig. 6. Haliclona (Flagellia) hamata (Thiele, 1903) subgen. et comb. nov., SEM images from a fragment of the holotype (SMF 1640) from Ternate, Indonesia. A. Oxea. A 1. Detail of one of the apices. B–C. Flagellosigmas. B 1. Detail of long ending of flagellosigma. B 2. Detail of short ending of flagellosigma. D. Sigmas.

Fig. 7. Haliclona (Flagellia) hamata (Thiele, 1903) subgen. et comb. nov., habitus of ZMA Por. 09285 from Sumba, Indonesia (scale bar = 1 cm).

Fig. 8. Haliclona (Flagellia) hamata (Thiele, 1903) subgen. et comb. nov., SEM images of spicules (ZMA Por. 09285). A. Oxea. A 1. Detail of one of the apices. B–C. Flagellosigmas. B 1. Detail of long ending of flagellosigma. B . Detail of short ending of flagellosigma. D. Sigmas.