Hamacantha (Vomerula) acerata Lévi, 1993

Ekins, Merrick, Baker, Soraya & Hooper, John N. A., 2023, First records of Hamacantha species from seamounts off eastern Australia (Porifera, Demospongiae, Merliida), with description of four new species, Zootaxa 5318 (3), pp. 382-400 : 383-384

Hamacantha (Vomerula) acerata Lévi, 1993

Figs 1 , 2 , Tables 1 , 2

Hamacantha acerata Lévi, 1993: 36–37 , Fig. 13A

Material examined: Holotype MNHN DCL 3594

Description: The skeletal structure was as described by Lévi (1993) so the original description is translated in full here (from the French). “ Description. Sponge attached to various small calcareous debris, light gray-white in colour, measuring 20/15/ 2 mm. The surface is reticulated. The superficial film, very thin, contains sigmanistres and some diancistres. The main skeleton consists of bundles of styles in groups of three, associated in thick or crisscross bundles. Some packets arrange themselves radially around grains of sand.” The spicules of the holotype were, however, examined in this study and measurements of spicules are included in Table 1 and compared to the original description of Lévi as well as another closely related species H. (V.) umisachii Ise, Woo, Tan & Fujita, 2019 from Japan and a new species Hamacantha (Vomerula) novacula sp. nov. from Australia.

Remarks: Hamacantha (V.) acerata Lévi, 1993 is very similar to H. (V.) umisachii differing only in the shape of the diancistra and the cyrtancistra-like diancistra, which Lévi (1993) referred to as sigmancistras. Lévi’s species also has smaller sigmas and slightly larger but overlapping style lengths than H. (V.) umisachii ( Tables 1 & 2 ). Interestingly, when H. (V.) umisachii was initially described by Ise et al. (2019) it was not compared to H. (V.) acerata . The smaller category of diancistra of H. acerata was also overlooked in Table 2 by Castello-Branco & Hajdu (2018) The recovery of more specimens in the future and their molecular sequencing may confirm whether these two nominal species are conspecific. Hamacantha (V.) carteri Topsent, 1904 also has a similar spicule composition as H. (V.) umisachii but with more significantly different spicule sizes ( Table 2 ). As well as H. (V.) acerata , H. (V.) umisachii and H. (V.) mamoi Ise, Woo, Tan & Fujita, 2019 , cyrtancistra-like diancistra have also been reported from H. (V.) jeanvaceleti Castello-Branco & Hajdu, 2018 , H. (V.) klausruetzleri Castello-Branco & Hajdu, 2018 , H. (Zygherpe) desmacelloides Hajdu, Hooker & Willenz, 2015 .

Figures

FIGURE 1. Sampling sites of Hamacantha species described in this study.

FIGURE 2. Hamacantha (Vomerua) acerata Lévi, 1993. A. Holotype MNHN DCL 3594 preserved specimen. B. Large diancistras. C. Diancistras (II) (referred to as Sigmancistras by Lévi (1993) and cyrtancistra-like diancistra by Ise et al. (2019). D. Sigma. E. Style.