Bolosoma perezi, Castello-Branco & Collins & Hajdu, 2020

Castello-Branco, Cristiana, Collins, Allen G. & Hajdu, Eduardo, 2020, A collection of hexactinellids (Porifera) from the deep South Atlantic and North Pacific: new genus, new species and new records, PeerJ 8, pp. e 9431-e 9431 : 11-13

Bolosoma perezi sp. nov.

( Figs. 6 and 7 )

Type Material

Holotype. MNRJ 21955 , Rio Grande Rise, Southwest Atlantic (PROERG Expedition , ERG 15 — L 2; 31 7 ′ 3.36 ″ S / 34 1 ′ 48.72 ″ W), 1,022– 1,013 m depth, 07.VII.2011. LSID: urn:lsid:zoobank.org:act:CAD5EDB9-DB39-4684-A160-95EA2FA21210

Diagnosis

Bolosoma perezi sp. nov. is the only Bolosoma with discohexasters and codonhexasters microscleres.

EXTERNAL MORPHOLOGY. Sponge fragment, cushion-shaped and compressible, 162 mm in length × 78 mm in width × 16–27 mm in height; fragment apparently without a peduncle, color light gray in ethanol (fi g. 6).

SKELETON AND SPICULES. A few long cemented diactins (40–80 m m diameter and over 900 m m long), which we assume are fragments of a peduncle. Choanosomal diactins with rough ends and rudiments of tangential rays (1,275–3,125 × 5–8 m m). Dermal and atrial hexactins and rare atrial pentactins with rough ends and sometimes random spines along the ray (270‒830 × 5‒8 m m). Microscleres are ball-like discohexasters (70‒80 m m diameter), its derivates (stauractins, 42–50 m m diameter), and codonhexasters (155–175 m m diameter, primary rosettes 27–43 m m diameter). The last one with six primary rays and secondary rays in number of four; discs with nine teeth (fi g. 7).

DISTRIBUTION AND ECOLOGY. Known only from its type locality in the Rio Grande Rise (Southwest Atlantic), 1,022–1,013 m depth. This is the fi rst record of Bolosoma for the entire Atlantic Ocean.

ETYMOLOGY. The speci fi c epithet honors Prof. Dr. Angel Perez (UNIVALI, Brazil) for granting us access to Rio Grande Rise materials, and for our long-standing collaboration in the study of South Atlantic deep-sea ecosystems.

Remarks

Bolosoma comprises eight species (see comparative Table 1 ), up to now recorded only from the Paci fi c Ocean. The new species presents a unique set of spicules, indicating its distinctiveness from the remaining species in the genus. None of its congeners present the combination of delicate codonhexasters and “ball-like” discohexasters, which confers B. perezi sp. nov. obvious status as a new species. This is the fi rst record of Bolosoma for the Atlantic Ocean.

Figures

Figure 6 Bolosoma perezi sp. nov. holotype (MNRJ 21955). (A) Specimen; (B, D and E) hexactins; (C) Choanosomal diactin; (F) detail of hexactin’s distal end of ray; (G and H) discohexasters; (I and J) codonhexasters; (K) anchorate end of a codonhexaster. Scales: (A) 10 mm; (B) 50 mm; (F, I, J and K) 10 mm; (C–E) 100 mm; (G and H) 20 mm. Full-size DOI: 10.7717/peerj.9431/fig-6

Figure 7 Schematic illustration of Bolosoma perezi sp. nov. codonhexaster (Illustration by Nicholas Bezio). Full-size DOI: 10.7717/peerj.9431/fig-7