Plocamione matarani, Recinos & Pinheiro & Willenz & Hajdu, 2020

Recinos, Radharanne, Pinheiro, Ulisses, Willenz, Philippe & Hajdu, Eduardo, 2020, Three new Raspailiidae Hentschel, 1923 (Axinellida, Demospongiae) from Peru, Zootaxa 4778 (3), pp. 521-545: 537-540

publication ID

https://doi.org/10.11646/zootaxa.4778.3.5

publication LSID

lsid:zoobank.org:pub:4E26C6E8-2895-4D12-BB7B-E59F9E890532

DOI

http://doi.org/10.5281/zenodo.3848062

persistent identifier

http://treatment.plazi.org/id/0E7F878A-9D32-FF98-FF36-F999577EA97E

treatment provided by

Plazi

scientific name

Plocamione matarani
status

sp. nov.

Plocamione matarani   sp. nov.

( Figure 4 View FIGURE 4 , Table 3)

Type locality: Peru, Matarani, Isla Blanca, Arequipa Region.

Holotype. MNRJ 12131 View Materials , Isla Blanca (17.0088° S– 72.1222° W), Matarani, Peru, 33 m depth, coll. Y. Hooker & U. Zanabria (26/XI/2008). GoogleMaps  

Diagnosis. Only Plocamione   with two categories of subectosomal styles, ectosomal megascleres (styles) always larger than 200 µm, but never as large as 500 µm, echinating acanthostyles in a single category which can be as small as 100 µm, and choanosomal acanthostrongyles, also in a single category, which can reach over 300 µm in length.

Description ( Fig. 4A View FIGURE 4 ). Thinly encrusting sponge (ca. 1 mm thick), reaching over 15 cm in its largest diameter. Surface uneven, bumpy, with trapped sediment. Oscula not seen. Colour orange in life, beige in preservation.

Skeleton ( Fig. 4B View FIGURE 4 ). Ectosomal skeleton with large piercing subectosomal styles surrounded by a loose bouquet of smaller ectosomal styles (and possibly toxiform oxeas). Choanosomal skeleton microcionid with architecture constructed over a dense, criss-cross layer of acanthostrongyles; as fibre nodes cored by large, stout styles, and echinated by acanthostyles; on top of which, although seemingly not always, sit the ectosomal bouquets.

Spicules ( Figs 4C –P View FIGURE 4 ). Ectosomal styles (229–350.3–405 / 2–4– 6 µm): slender, smooth, slightly or markedly curved, tapering gradually, rounded heads and hastate tips ( Fig. 4G View FIGURE 4 ). Subectosomal styles I (1068–1295.6–1551 / 12– 19.7– 25 µm): large, slender, smooth, slightly curved, tapering gradually, rounded heads and hastate tips ( Figs 4 View FIGURE 4 C–D). Subectosomal styles II (263–452.5–689 / 11–19.6– 26 µm): coring fibre nodes, stout, smooth, straight or slightly curved, tapering gradually to sharp apices, rounded heads and hastate tips ( Figs 4 View FIGURE 4 E–F, 4H). Choanosomal acanthostrongyles (126–159.8–363 / 5–8.9–11/ 5–7.1– 10 µm, length/ width thicker/ thinner ends): aniso-, curved and slightly sinuous, spined at both ends only, spines conical and rounded heads, the heads vary in width ( Figs 4 View FIGURE 4 I–K). Echinating acanthostyles (93–156.7–231 / 8–10.8– 14 µm): echinating fibre nodes, short, straight or slightly curved, spines generally concentrated on their apical half, a few at the base, spines conical or bent as hooks, verrucose at tyle heads, acerate tips ( Figs 4 View FIGURE 4 L–P). One toxiform oxea was seen, possibly homologous to the styles of the bouquets.

Bathymetric distribution and ecology. The sponge was sprawling over vertical rocky substrate at 33 m depth, associated to many brachiopods, anthozoans, sea urchin, and another encrusting sponge (yellow coloured).

Distribution. Known only from Isla Blanca, Matarani, in Peru.

Etymology. The species name, matarani   , refers to the type locality of the species, Isla Blanca, off Matarani

Remarks. The new species is by far the shallowest ever found in Plocamione   , whose previously known shallowest depth was 182 m, off New Zealand ( P. ornata   ). The latter is one of only two species in the genus known from the Pacific, the other being P. pachysclera   (from 400 m deep waters off New Caledonia). Plocamione matarani   sp. nov. is quite distinct from every other known Plocamione   by a series of spicule characteristics highlighted below in a one by one comparison with other congeners ( Table 3, including taxonomic authorities). Considerably larger subectosomal spicules set P. dirrhopalina Topsent, 1927   apart from the new species, while considerably smaller set P. hystrix   ( Ridley & Duncan, 1881; ca. 2000 m depth) and P. ornata   apart. Plocamione dirropalina   further differs by its much larger ectosomal megascleres, and much smaller acanthostrongyles, aside its deeper than 1200 m Mediterranean habitat. Much smaller acanthostrongyles strengthen P. ornata   ’s distinction from the new species, as they do for P. carteri ( Ridley & Duncan, 1881)   and P. clopetaria   ( Schmidt, 1870; ca. 490 m depth). Lastly, P. pachysclera   , whose originally reported acanthostyles, given their abundance and stoutness, are to be equated with the acanthostrongyles of additional Plocamione   spp., can be easily set apart from the new species by this referred stoutness (albeit its shorter ‘plocamiid’ megasclere), as well as the seemingly unique occurrence of two categories of ectosomal megascleres. However, the likelihood that P. pachysclera   indeed belongs in Plocamione   appears weak to us, starting from its unique bushy-ramose habit, when every other Plocamione   has been reported to be encrusting. Lévi & Lévi (1983) chose Raspailia   as their preferred assignment for the species, recognizing though that the ectosomal acanthostyles in their species appeared quite distinct from the usual slender styles and oxeas in other Raspailia   spp., while mentioning that the stout acanthostyles in the New Caledonian sponge, concentrated at the base, albeit morphologically distinct, suggested affinity with Plocamione   . It is possible that this sponge actually belongs in a new genus.