Haliclona (Rhizoniera) zanabriai, Bispo & Willenz & Hajdu, 2022

Bispo, André, Willenz, Philippe & Hajdu, Eduardo, 2022, Diving into the unknown: fourteen new species of haplosclerid sponges (Demospongiae: Haplosclerida) revealed along the Peruvian coast (Southeastern Pacific), Zootaxa 5087 (2), pp. 201-252 : 240-242

Haliclona (Rhizoniera) zanabriai sp. nov.

( Figure 14 , Table 3 )

Holotype. MNRJ 12155 (Vouchers: RBINS-IG 32240 -POR 12155, MHNG 85598 ) Isla Blanca , Matarani, Arequipa Region (17º00’31.50” S, 72º07’19.90” W —Matarani, Arequipa), depth between 4.5–20 m, coll. Y. Hooker & U. Zanabria (28/XI/2008).

Diagnosis. The only Haliclona in the Eastern Pacific with a combination of cushion-shaped habit, short lobate projections or small ridges, punctate and flat surface, colour alive light-brown, an anisotropic skeleton with uni- to paucispicular primary tracts, and oxeas 79–163 µm in length.

Description ( Fig. 14A, B ). Thickly encrusting specimen, 5–9 mm thick, with short lobate projections or small ridges, irregularly sprawling, attaining largest diameters of over 30 cm. Surface somewhat punctate. Oscula abundant, circular, 1–2 mm in diameter, mostly flush with the surface. Consistency soft, compressible. Colour in life light brown.

Skeleton ( Fig. 14C, D ). No specialized ectosomal skeleton. Choanosome an anisotropic reticulation with ascending, somewhat regular, primary uni- to paucispicular tracts (1–5 spicules thick), connected by mostly unispicular secondary tracts in varied angles of attachment; overall construction quite loose. Large lacunae present, up to 300 µm in diam., and a few, likely younger spicules, scattered all around. Spongin scarce, at the nodes of the reticulation.

Oxeas ( Fig. 14E–G ). Oxeas, fusiform, straight, or more frequently subtly bent at centre, long acerate points, 79– 123 –163 µm x 1.0– 5.1 –9.0 µm (n = 40 x 20).

Ecology. Occur on shallow rocky substrate in the subtidal zone, partly epibiont on large barnacles, and associated with red algae, shrimps, a blenny, and a dense mat of short polyps (likely Hydractinia sp. ). Though the depth during collection was not recorded, the maximum depth reached on this dive was 20 m.

Distribution ( Fig. 3E ). Only known from its type locality at Isla Blanca (Matarani, Arequipa Region), in Peru.

Etymology. We dedicate this species to Ulrich Zanabria for his efficient buddy diving assistance during our stay in Matarani, which involved several deeper dives.

Remarks. Haliclona (Rh.) zanabriai sp. nov. is better assigned to H. (Rhizoniera) given its anisotropic skeleton, somewhat regular, with scarce spongin, and long-pointed oxeas ( de Weerdt 2002). Several Haliclona spp. along the Eastern Pacific share with the new species the presence of uni- to multispicular primary lines with scarce spongin, demanding the comparisons provided below ( Table 3 ). The Californian H. (Rh.) enamela has a brown colour, smooth to verrucose surface, and anatomy including a dense reticulation with primary lines 6–8 spicules thick ( de Laubenfels 1932). In contrast, H. (Rh.) zanabriai sp. nov. has a flat surface without verrucose projections, and a much less dense skeleton, with primary lines only 1–5 spicules thick. Both species appear thus easily distinguishable.

The remaining eastern Pacific Haliclona spp. with uni- to multispicular primary lines are the Chilean H. (Rh.) anceps , H. (S.) auletta , H. (S.) chilensis , H. (S.) inepta ( Thiele, 1905) , H. (Halicl.) macropora, H. rugosa ( Thiele, 1905) , H. (Re.) sordida , H. (Halich.) thielei, and H. (Halicl.) verrucosa. The new species is promptly set apart from H. (S.) inepta and H. (Re.) sordida (both from the Magellanic Province) given its non-overlapping smaller oxeas (79–163 µm long in H. (Rh.) zanabriai sp. nov. vs. 180–200 µm in H. (S.) inepta and ca. 200 µm in H. (Re.) sordida ) ( Thiele 1905; Hajdu et al. 2013). In turn, H. (S.) auletta and H. (S.) chilensis (also from the Magellanic Province) have a distinct tubular shape, and conulose surface in the former ( Thiele, 1905), so that conspecificity with H. (Rh.) zanabriai sp. nov. is rather unlikely.

Other Magellanic species that also resemble the new species are H. rugosa and H. (Halicl.) verrucosa. Their suggestive names derive from their particular habit with an irregular surface that might bear swellings in H. rugosa , or prominent verrucose projections in H. (Halicl.) verrucosa. In addition, H. rugosa has a hemispherical shape, blue-grey colour alive, and oxeas 150 µm long; while H. (Halicl.) verrucosa has oxeas 150–165 um long, joined in basal areas by abundant spongin ( Thiele 1905). Therefore, their conspecificity with H. (Rh.) zanabriai sp. nov. is also unlikely.

The taxonomic problem of H. (Halich.) thielei was treated in the Remarks section of H. (Halich.) arequipaensis sp. nov. Still, none of the ‘forms’ of H. (Halich.) thielei are conspecific with H (Rh.) zanabriai sp. nov., as the “spicule reinforced” one has a dense, irregular skeleton, and blue-green or grey-violet colour; and the “spongin reinforced”, a much more regular skeleton, and apical oscula on conical elevations up to 3 mm high ( Thiele 1905).

Haliclona (Rh.) anceps and H. (Halicl.) macropora, from the Juan Fernandez Archipelago, approach the habit of H. (Rh.) zanabriai sp. nov., all sharing the presence of pauci- to multispicular tracts in the skeleton too. However, H. (Rh.) anceps is a grey-yellowish sponge, with irregular meshes in the choanosomal reticulation, bearing short pauci- to multispicular tracts beneath the surface, some of which may pierce the ectosome. Roughly speaking, this doesn’t match the new species’ brown colour and choanosomal architecture with deep, more regular longitudinal tracts, overlaid by spicules in confusion ( Thiele 1905). In spite of the punctate surface and skeletal architecture much alike the new species in H. (Halicl.) macropora, it has projecting spicule tracts that produce conules on the surface ( Thiele 1905), a feature not observed in H. (Rh.) zanabriai sp. nov. In addition, H. (Rh.) zanabriai sp. nov. has abundant oscula, while these are rare in H. (Halicl.) macropora, with only two reported in its type material ( Thiele 1905).

Figures

FIGURE 3. Map showing the geographic distribution of Peruvian haplosclerids. A, distribution of Chalinula chelysa sp. nov.; B, distribution of Chalinula ramiculosa sp. nov. and Haliclona (G.) concreta sp nov.; C, distribution of H. (Halich.) arequipaensis sp. nov., H. (Halich.) multiosculata sp. nov. and H. (Halich.) marcoriosi sp. nov.; D, distribution of H. (Halich.) paracas sp. nov., H. (Halich.) pellucida sp. nov. and (Reniera) parvuloxea sp. nov.; E, distribution of H. (Rhizoniera) spp. nov.; F, distribution of Niphates ruthecitae sp. nov. and Pachychalina lupusapia sp. nov.

FIGURE 14. Haliclona (Rhizoniera) zanabriai sp. nov. (MNRJ 12155). A–B, holotype alive; C, skeletal architecture in transverse ground section stained with acid fuchsine; D, detail of C; E–G, oxeas. Scale bars: A, 10 cm; B, 1 cm; C, 500 μm; D, 200 μm; E–G, 20 μm.