Haliclona (Soestella) battershilli, 2019

Kelly, Michelle & Rowden, Ashley A., 2019, New sponge species from hydrothermal vent and cold seep sites off New Zealand, Zootaxa 4576 (3), pp. 401-438 : 404-415

Haliclona (Soestella) battershilli sp. nov.

( Figs 1–4 ; Table 1, 2)

Haliclona n. sp. cf. kaikoura, Stoffers et al. 1999: 66 , 247.

Material examined. Calypso hydrothermal vent field (Southern vent field, unless noted otherwise), southwest of White Island, Bay of Plenty : Holotype — NIWA 32128 , University of Kiel Stn SO192-2/2, 37.688° S, 177.122° E, 189 m, collected by ROV, 24 Apr 2007. Paratypes — NIWA 52850 , IFM GEOMAR Stn SO135/103, 37.695° S, 177.101° E, 179–181 m, collected by rock dredge, 10 Oct 1998 ; NIWA 52895 , IFM GEOMAR Stn SO135/102, 37.698° S, 177.099° E, 177–185 m, collected by rock dredge, 9 Oct 1998 ; NIWA 52921 , IFM GEOMAR Stn SO135/110, 37.688° S, 177.122° E, 189–192 m, collected by rock dredge, 11 Oct 1998 ; NIWA 52872 , IFM GEOMAR Stn SO135/108, 37.687° S, 177.121° E, 193 m, collected by submersible, 10 Oct 1998 .

Other material. Calypso hydrothermal vent field (Northern vent field): NIWA 99603 , IFM GEOMAR Stn SO 135/117, 37.614° S, 177.100° E, 162 m, collected by rock dredge, 11 Oct 1998 .

Type location & distribution. Calypso hydrothermal vent field, Bay of Plenty, New Zealand, 162–193 m.

Description. Sponge forms a tangled mass emanating from what appears to be either a single point of attachment to hard substrate, or an encrustation ( Figs 2 , 3A ; see also Fig. 5A ). Immature sponges form a solitary, short stubby to elongate irregular finger, often branched into two or three fingers, length about 10–20 cm long, 4– 10 mm thick. As the sponge grows, the basal branch splits, branches anastomosing to form a large tangled mass, up to about 40 cm long and 30 cm wide. Oscules, 2–5 mm diameter, are raised on low mounds on older, basal branches, rendering the surface knobbed, almost ribbed in appearance (see Fig. 5A ). The surface of younger sections is smooth and oscules are flush with the overall surface, slightly concave in preservative. Texture in life slightly compressible, younger sections more fragile and compressible, older, basal sections firmer slightly elastic and reasonably flexible. Brittle on tearing. Surface texture slightly fuzzy, microscopically hispid. Colour in life light cream; in preservative pale tan.

Skeleton. Skeleton of the deep choanosome consists of rare, uni- to multispicular primary lines ( Fig. 3C , red arrows), joined in places by single spicules ( Fig. 3C , white arrows), with evidence of some minor subisodictyal reticulation. The majority of the choanosome has little order, rather, consisting of abundant, scattered spicules, surrounding subdermal spaces of variable size. The ectosome is highly irregular with spicules protruding obliquely or with no obvious orientation, creating the slightly velvety surface texture. Spongin is not visible but most likely limited to the nodes of connection between oxeas.

Spicules. Megascleres ( Table 1; Fig. 4 ) thick oxeas, fusiform, slightly curved to abruptly, slightly centrally bent, 203 (159–231) × 11 (5–15) µm.

Substrate, depth range and ecology. Attached to volcaniclastic rock covered in sediment and associated with high densities of an undescribed orange anemone, and other sponges, 177– 193 m.

Etymology. Named for Professor Christopher N. Battershill, University of Waikato, who first identified this species as Haliclona n. sp. cf. kaikoura Bergquist & Warne, 1980 and who noted the potential significance of the association between the sponges and active hydrothermal venting at the Calypso hydrothermal vent field ( Stoffers et al. 1999).

Remarks. In general terms, the skeletal architecture of Haliclona battershilli sp. nov. conforms to something between that of Haliclona (Haliclona) species sensu de Weerdt (2000, 2002 ), which have a very regular ladder-like reticulation of uni- to pausispicular primary lines connected by unispicular secondary lines, and Haliclona (Soestella) de Weerdt, 2000 species, which have a subanisotropic choanosomal skeleton of ill-defined pausispicular primary lines, irregularly connected by pausispicular secondary lines, with a slight tendency to form rounded meshes (de Weerdt 2000, 2002). The choanosome of Haliclona battershilli sp. nov. has only occasional unispicular primary lines visible, joined occasionally by single spicules ( Fig. 3C ) [as in Haliclona (Haliclona) ], interspersed with numerous interstitial oxeas strewn around a reasonably cavernous choanosome. The skeleton approaches Haliclona (Soestella) in this way but does not form strictly rounded meshes. In the face of these difficulties, we consider the skeleton architecture to be closer to that of Haliclona (Soestella) than to that of Haliclona (Haliclona) species and have assigned the new species to the subgenus Haliclona (Soestella) accordingly.

Stoffers et al. (1999: 66) describe, “a large very dense anemone assemblage with white finger sponge ( Haliclona n. sp.) together with bacterial mats” as, “a striking assemblage,” that was listed as specific to the venting areas ( Stoffers et al. 1999: 72; Species/geological associations: 1–white bacterial mat, brown anemone and white finger sponge/Rock outcrops, bubbles, high temperatures). The ‘white finger sponge’ is named in Stoffers et al. (1999: Appendix 6-3) as Haliclona n. sp. cf. kaikoura Bergquist & Warne, 1980 , which forms branches that arise from a flattened base, but this species has a conspicuous punctate, reticulate surface and much smaller oxeas [ H. kaikoura : 130 (124–149 µm); H. (S.) battershilli : 203 (159–231 µm)]. Haliclona kaikoura has only been recorded from the east coast of the South Island.

Locality & depth Morphology & colour Skeleton Spicule dimensions Comment

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In terms of spicule dimensions, most New Zealand Haliclona species have oxeas that range in length from about 100–150 µm ( Table 2); H. sabulosa Bergquist & Warne, 1980 , has the smallest oxeas, at 81 (68–95) × 5 µm and H. maxima Bergquist & Warne, 1980 has the largest, at 293 (274–317) µm long. With oxeas that range in length from 159–231 µm, H. (S.) battershilli sp. nov. has the second largest spicules recorded for a species of Haliclona in New Zealand.

The three species most closely comparable to H. (S.) battershilli sp. nov., in terms of oxea dimensions, are H. fragilis ( Bergquist & Warne, 1980) , H. ‘laxa’ ( Lundbeck, 1902) sensu Brøndsted (1924) [ H. laxa ( Lundbeck, 1902) is now accepted as Haliclona (Rhizoniera) rosea ( Bowerbank, 1866) in the World Porifera Database (van Soest et al. 2018d)], and H. (S.) implexa (Schmidt, 1868) sensu Brøndsted (1924: 122) and Bergquist & Warne (1980: 17). Haliclona fragilis has oxeas 175 (131–197) µm long, and has a loose, unispicular reticulation with visible spongin, and has only been recorded from the lower intertidal (Auckland west coast) and shallow subtidal (South Island east coast). Haliclona (R.) rosea from Colville Channel in the Hauraki Gulf, is probably the closest species to H. (S.) battershilli sp. nov., with oxeas 190–200 µm long, and recorded from 64 m depth. However, H. (R.) rosea was described as tubular, about 14 cm long, with a wall about 8 mm thick. The skeleton is also similar, described as very dense with numerous interstitial spicules and composed primarily of primary fibres, 2–6 spicules wide. The primary fibres in H. (S.) battershilli sp. nov. are rare and unispicular. Haliclona (S.) implexa was recorded from shallow waters in the Subantarctic region of New Zealand, but Brøndsted’s description does not conform to that of Soestella sensu stricto ( Table 2), and the species is now reserved for Northern Atlantic and Mediterranean sponges; the New Zealand distribution is considered to be inaccurate ( Van Soest 2017f).

Despite the general difficulty of differentiating the many species of Haliclona in New Zealand waters, we regard H. (S.) battershilli sp. nov. as unique, due to: 1) the restricted distribution to the Calypso hydrothermal vent fields; 2) the depth of this habitat (180–190 m), the deepest record for any species of Haliclona in New Zealand waters thus far; 3) the considerable size of the oxeas (159–231 µm) compared to most other species; and 4) the branching, ramose, attenuated habit, not found in any other New Zealand species.

Figures

FIGURE 1. Map showing type localities for new species described from the Calypso hydrothermal vent field in the Bay of Plenty and named seep sites on the Hikurangi Margin.

FIGURE 2. Photograph of seabed at Southern vent field of the Calypso hydrothermal vent field (NIWA Stn KAH1004/8: image 1119; 37.688° S, 177.123° E, 190 m), showing the three sponge species that dominate the epifauna assemblage at this site: Blue arrow—finely branched Haliclona (Soestella) battershilli sp. nov.; Red arrows—translucent white, cushion-shaped Haliclona (Halichoclona) sonnae sp. nov.; Green arrows—stubby fingered, peach-coloured Protosuberites novaezelandiae sp. nov. The orange anemone is undescribed. Image captured by NIWA’s DTIS (Deep Towed Imaging System) deployed from RV Kaharoa.

FIGURE 3. Haliclona (Soestella) battershilli sp. nov.: A. Finely branched, tangled masses dominate sediment-covered hard substrate at the Southern vent field of the Calypso hydrothermal vent field (NIWA Stn KAH1004/8: image 1112; 37.688° S, 177.123° E, 190 m); B. Preserved holotype NIWA 32128, showing fragments of branches and large, flush oscules; C. Composite image of a histological section of paratype NIWA 52895, showing a cavernous choanosome through which occasional primary lines emerge towards the surface (red arrows), connected in places by unispicular secondary lines (white arrows), and the dense interstitial oxeas. Image in 3A captured by NIWA’s DTIS (Deep Towed Imaging System) deployed from RV Kaharoa.

FIGURE 4. Haliclona (Soestella) battershilli sp. nov., holotype NIWA 32128, spicules: A. Oxea megascleres, thick, fusiform, slightly curved (lower left to middle), to abruptly, slightly centrally bent (upper right); B. Range of oxeas showing degrees of curvature.

FIGURE 5. Haliclona (Halichoclona) sonnae sp. nov.: A. Encrusting, cushion-shaped specimens in situ (red arrows) intermingled with Haliclona (Soestella) battershilli sp. nov., at Southern vent field of the Calypso hydrothermal vent field (NIWA Stn KAH1004/8: image 1113; 37.688° S, 177.123° E, 190 m); B. Preserved holotype, NIWA 52859, showing cavernous interior and thick, flaky ectosome; C. Histological section of holotype showing the thick ectosome, dominated by an irregular, ladder-like reticulation, overlaid at the surface with a thin layer of paratangential oxeas. Also showing the highly cavernous subectosomal region separating the outer ectosome from the deeper choanosome; D. Histological section of the deep choanosome showing the loose, irregular, subisotropic to confused reticulation of oxeas in the choanosome, interrupted by large subdermal canals and spaces. Image in 4A captured by NIWA’s DTIS (Deep Towed Imaging System) deployed from RV Kaharoa.