Antho (Plocamia) sarasiri,

Costa, Gabriele, Pansini, Maurizio & Bertolino, Marco, 2019, A new sponge species of the genus Antho (Demospongiae, Microcionidae) from the Tyrrhenian deep Sea, Zootaxa 4674 (3), pp. 397-400: 397

publication ID

https://doi.org/10.11646/zootaxa.4674.3.9

publication LSID

lsid:zoobank.org:pub:AF6F4F2C-F5B3-4F03-AA94-D24CFD342AD0

persistent identifier

http://treatment.plazi.org/id/03AA87A3-FFE1-072B-FF3F-9DF1422BFB81

treatment provided by

Plazi

scientific name

Antho (Plocamia) sarasiri
status

sp. nov.

Antho (Plocamia) sarasiri  sp. nov.

MATERIAL Holotype: Rete Bruno B, Secca P.ta Fetovaia , Elba Island , North Tyrrhenian Sea , 13.06.2012, 70 m depth [ MSNG 60890]  . Comparative material: (15), Gaiola , Gulf of Naples , 17.11.1959, detritic bottom, exact depth unknown  ; (319), Gaiola , Gulf of Naples , detritic bottom, 40–50 m, Sarà & Siribelli , 1960  . (450:3), Benda Palummo , Gulf of Naples , on rocky fragments, 10.5.1961, 50– 70 m depth  ; (567:5), Benda Palummo , Gulf of Naples , on mollusc shell, 19.7.1961, 50– 70 m depth, Sarà & Siribelli , 1962. 

DESCRIPTION Holotype ( Figure 1AView FIGURE 1) is a small (2 cm across) incrustation on a piece of coralligenous concretion. The surface is rather hispid and the colour brown in the dry state. No oscules are detectable. The comparative material, encrusting on rock and a mollusc shell, looked red in colour and slimy according to Sarà & Siribelli (1960, 1962) who observed it fresh after collection.

Skeleton. No discrete ectosomal skeleton. A damaged dermal membrane is supported by the reticulation below ( Figure 1BView FIGURE 1). Ectosomal subtylostyles and structural styles, apparently not forming brushes, rendering the sponge surface slightly hispid ( Figure 1DView FIGURE 1). Choanosome with a rather dense reticulation forming irregular meshes of one to three dumbbell spicules at a side ( Figure 1CView FIGURE 1), echinated by acanthostyles ( Figure 1DView FIGURE 1). Mesh size 143 (218) 285 µm. Ascending tracts are sometimes detectable ( Figure 1EView FIGURE 1). Isochelae densely packed ( Figure 1FView FIGURE 1) and included in the network.

Spicules (micrometers in Table 1). Ectosomal subtylostyles, gently curved, with smooth or finely spined heads. Spines short and often blunt ( Figure 2AView FIGURE 2). Ectosomal subtylostyles, straight, with a few spines on the head, and on the proximal third of the shaft ( Fig. 2DView FIGURE 2). Dumbbell spicules, slightly curved, generally with well formed heads but also in form of almost straight strongyles. The head spines are sharp or blunt ( Fig. 2BView FIGURE 2). Acanthostyles slightly curved with microspines on the heads, and on the proximal third of the shaft ( Figure 2CView FIGURE 2). Microscleres toxas with a slight curvature reminding the oxhorn morphotype, or sometimes straight ( Fig. 2EView FIGURE 2). Palmate isochelae with a straight regular shaft, often twisted ( Fig. 2FView FIGURE 2).

ETYMOLOGY The name “sarasiri” is derived from the union of the names of the authors, Sarà and Siribelli, who first recorded this new species from the Gulf of Naples that confused her with Antho (Acarnia) circonflexa (Lévi, 1960)  . ECOLOGY The species has been found on hard substrata in the Thyrrenian Sea (from the Gulf of Naples to Elba Island). The depth range is 40– 70 m.

REMARKS The new species has been ascribed to the genus Antho  , subgenus Plocamia Schmidt, 1870  according to the presence of dumbbell spicules that form the reticulation of the basal choanosomal skeleton. Van Soest et al. (2013) reassign to Antho (Plocamia)  14 species in total (11 in WPDB), no one of which is present in the Mediterranean Sea. However three of them: Antho (Plocamia) erecta (Ferrer Hernandez, 1923)  , A. (P.) hallezi (Topsent, 1904)  and A. (P.) anisotyla (Lévi, 1960)  have an East Atlantic distribution. These three are erect species and differ from the new one proposed by their different shape and spicule measurements. Sarà & Siribelli (1960, 1962) firstly recorded A. (P.) sarasiri  sp. nov. from two detritic banks of the Gulf of Naples, but attributed it to A. (Acarnia) circonflexa (Lévi, 1960)  . Actually, the two species are rather similar, but A. (Plocamia) sarasiri  differs from A. (A.) circonflexa  in the larger size of megascleres ( Tab. 1), in the swollen extremities of the dumbbell spicules, and in the thickness of toxas. As to the subgenus assignment of the new species, we believe it is justified by the swollen dumbbell spicules, whereas the attribution to the same subgenus of A. circonflexa  is not considered correct by Van Soest et al. (2013), probably due to the shape of the acanthostrongyles which are faintly tylote (Lévi 1960).