Haliclona (Halichoclona) paracas Bispo & Willenz & Hajdu 2022, sp. nov.
Creators: name: Bispo, André
name: Willenz, Philippe
name: Hajdu, Eduardo
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Haplosclerida
Chalinidae
Haliclona
Haliclona paracas

description: Haliclona (Halichoclona) paracas sp. nov.
(Figure 9, Table 3)
Holotype. MNRJ 12841 (Vouchers: RBINS-IG 32240 -POR 12841, MHNG 85674)— Unnamed Locality #2, Isla Santa Rosa, Reserva Nacional de Paracas, Ica Region (14°19’10.2” S, 76°09’52.4” W), depth 8 m, coll. Y. Hooker, F. Azevedo & Ph. Willenz (10/XII/2008).
Comparative material. Reniera algicola Thiele, 1905: ZMB POR 3320 — syntype (slides), Talcahuano, Chile.
Diagnosis. The only Haliclona in the Eastern Pacific with a combination of thinly encrusting habit, beige colour alive, abundant oscula about 1 mm wide, punctate surface, and an isotropic and dense reticulation of oxeas 157–211 µm long, without spicule tracts.
Description (Fig. 9A, B). Thinly encrusting, ca. 1–3 mm thick, occupying an area of ca. 6.0 x 3.5 cm. Surface smooth, punctate, with small volcaniform projections, 1.0– 1.6 mm high, topped by an oscule. Oscula common, circular, 0.8–1.2 mm wide. Consistency firm, but compressible. Colour alive beige, colour in ethanol yellowish cream.
Skeleton (Fig. 9C–E). Ectosomal skeleton a dense, uni- to paucispicular, isotropic reticulation, slightly confused, but with some discernible triangular to squared meshes (Fig. 9E). Choanosome of the same structure as the ectosome, albeit there are some subectosomal and choanosomal spaces, 600–1500 µm (Fig. 9C, D). Spongin scarce, only observed at the nodes of the reticulation.
Spicules (Fig. 9F, G). Oxeas, slightly curved, acerate, 157– 187 –211 x 5.1– 10.2 –12.8 µm (n = 30 x 30).
Ecology. Found on rocks at 8 m depth, together with other sponges and sea anemones. Water temperature during collections was 14° C.
Distribution (Fig. 3D). Only known from its type locality, Isla Santa Rosa (Ica Region), in Peru.
Etymology. The epithet “ paracas ” is used as a noun in apposition referring to the Marine Protected Area of Paracas, where Isla Santa Rosa (type locality) is located.
Remarks. The isotropic reticulation of the new species could fit both in H. (Reniera) or H. (Halichoclona). However, we decided for the assignment to H. (Halichoclona) based on the presence of a dense and confused reticulation in areas of the choanosome, in addition to the presence of choanosomal and subectosomal spaces. In addition, the ectosomal skeleton is supposed to be very regular and unispicular in H. (Reniera) (de Weerdt 2002), which diverge from the dense, uni- to paucispicular and slightly confused ectosome in H. (Halich.) paracas sp. nov.
Eastern Pacific Haliclona spp. with encrusting shape and/or colour similar to the new species include 13 species (Table 3). Those that can be readily set apart from the new species based on their smaller oxeas are H. (Re.) topsenti (Thiele, 1905) (up to 150 µm), H. (Halicl.) macropora (Thiele, 1905) (104–124 µm), H. (Halicl.) sonorensis Cruz- Barraza & Carballo, 2006 (100–145 µm), H. (Re.) oberi Sim-Smith, Hickman Jr. & Kelly, 2021 (118–154 µm), H. (Rh.) anceps (up to 150 um) H. (Rh.) enamela (up to 120 µm), H. (S.) roslynae (93–117 µm), H. (Halich.) thielei (125–150 µm) and H. translucida Desqueyroux-Faúndez, 1990 (94–116 µm).
The new species and H. (Re.) algicola share similarly sized and shaped oxeas. Nevertheless, the light grey colour of the latter alive and the brownish colour when fixed, somewhat diverges from the beige colour in life and yellowish cream in ethanol observed in the new species. We examined an original slide of H. (Re.) algicola syntype (ZMB POR 3320), where we did not observe very abundant spongin in the reticulation. Contrastingly, we could observe a much more irregular and much looser reticulation in H. (Re.) algicola than in the new species. We believe the distinct colour in life and these small skeletal differences set both species apart. The reticulation in H. (Re.) algicola looks less regular than that commonly found in H. (Reniera). Nevertheless, the examined slides are insufficient to review its subgeneric assignment.
The new species differs from H. (Re.) sordida based on the latter’s verrucose surface, grey-brown colour and presence of ascending paucispicular tracts in the choanosome (Thiele 1905). Haliclona (Halich.) gellindra differs by its pale-lavender colour, in addition to rare and irregular oscula (de Laubenfels 1932). In its turn, H. (S.) spuma has a subanisotropic reticulation of multispicular primary lines and pauci- to multispicular secondary lines and is thicker, 5–20 mm, than the new species (Sim-Smith et al. 2021).
description: Published as part of 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), pp. 201-252 in Zootaxa 5087 (2) on pages 230-232, DOI: 10.11646/zootaxa.5087.2.1, http://zenodo.org/record/5824017