Prosuberites laughlini ( Díaz, Alvarez & van Soest, 1987 )

Bettcher, Larissa, Fernandez, Julio C. C., Gastaldi, Marianela, Bispo, André, Leal, Camille V., Leite, Dora, Avelino-Alves, Dhara, Clerier, Pedro H. B., Rezende, Dafinny, Gulart, Clara M. R., Pinheiro, Ulisses & Hajdu, Eduardo, 2023, Checklist, diversity descriptors and selected descriptions of a highly diverse intertidal sponge (Porifera) assemblage at Costa do Descobrimento (Bahia, Brazil), Zootaxa 5277 (3), pp. 443-489 : 458-459

Prosuberites laughlini ( Díaz, Alvarez & van Soest, 1987)

( Tab. 1–2, 4; Fig. 7A–E )

Synonymy. Eurypon laughlini, Díaz et al. (1987) .

Studied material. MNRJ 21505 , P.M. M. Recife de Fora (16°24.294′ S, 38°59.143′ W, Porto Seguro, BA, Brazil), intertidal, coll. Hajdu, E. & Avelino, D., 21 st April 2019 .

Description. Thinly encrusting (<1 mm thick); 4 cm in maximum diameter. Surface rugose, due to irregularities in the underlying substrate, pierced by apices of megascleres. Color in vivo orange-yellow, and beige in fixative ( Tab. 4; Fig. 7A ).

Skeleton. Unspecialized ectosome, pierced by large choanosomal megascleres. Choanosome with a basal layer of spongin, a little sediment (including sand grains) and megascleres erect on the substrate/basal layer of spongin, bases down. Some megascleres (smaller ones) totally embedded in the choanosomal region ( Figs. 7B–C )

Spicules. Megascleres only ( Tab. 4; Figs. 6D–E ): tylostyles, slightly curved, pronounced head, with slight variation in overall shape, 231–431.1– 1174 x 9.7–14.0–18 µm.

Distribution. Previously, West Indies (Southern Caribbean— Diaz et al. 1987), Central America ( Belize — Ŗtzler et al. 2000; Panama — Diaz 2005), Suriname ( van Soest 2017). New record—Southwestern Atlantic (Costa do Descobrimento, BA, Brazil).

Ecology. Encrusting calcareous substrate on the underside of a boulder, next to a diverse assemblage of organisms comprising other sponges, polychaetes and bryozoans. The species appears to be rare in the study area as only a single specimen was collected in five expeditions. Study of the specimen in the lab revealed the presence of Cliona cf. mucronata Sollas, 1878 excavating its substrate (see below).

Remarks. The specimen reported upon here perfectly matches the few available previous descriptions for the species. Live color, surface characteristics, shape and dimensions of spicules fit well with the description of Diaz et al. (1987) and van Soest (2017). The large apparent distribution gap between the southern Bahia / Brazil and Suriname records is most likely an artefact of insufficient sampling or taxonomic effort.

Figures

FIGURE 6. Venn diagram showing the numbers of unique and shared species among the reefs surveyed at Costa do Descobrimento (Bahia, Brazil). P.M.M. Coroa Alta (CA), Coroa Vermelha/Mutá (CVM), Arraial D’Ajuda (AA) and P.M.M. Recife de Fora (RF).

FIGURE 7. Prosuberites laughlini (Díaz, Alvarez & van Soest, 1987), MNRJ 21505: A, specimen in life; B, transverse sections showing tylostyles oriented perpendicularly to the substrate; C, detail of the heads embedded in a basal plate of spongin; D, tylostyles in different sizes and E, detail of the extremities of the tylostyles (from largest to smallest tylostyle, respectivelly).