Paraleucilla perlucida Azevedo & Klautau, 2007

Paraleucilla perlucida Azevedo & Klautau, 2007 View in CoL

( Figs. 17–19 View FIGURE 17 View FIGURE 18 View FIGURE 19 ; Table 9)

Synonyms: Leucilla australiensis (in part.)— Borojević & Peixinho 1976: 1031 [non L. australiensis ( Carter, 1886) ]. Paraleucilla perlucida — Azevedo & Klautau 2007: 07; Muricy et al. 2011: 26; Cóndor-Luján et al. 2019: 1816.

Type locality: Botinas Islands , Angra dos Reis, Rio de Janeiro State, Brazil .

Material examined: MNRJ30131 View Materials , MNRJ30133 View Materials , Búzios Island , Ilhabela, São Paulo State, Brazil, depth 8 m, coll. E. Hajdu & M. Ventura, 30/IV/2002 . MNRJ30134 View Materials , Celada , São Sebastião Island, Ilhabela, São Paulo State, Brazil, depth 8 m, coll. E. Hajdu & M. Carvalho, 01/ V /2002. UFRJPOR6891, 6892, Saco do Poço , São Sebastião Island, Ilhabela, São Paulo State, Brazil, depth 7 m, coll. F. F. Cavalcanti, 03/XII/2008 . UFRJPOR6894, Saquinho da Sumítica , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 9 m, coll. F. F. Cavalcanti, 01/XII/2008 . UFRJPOR7015, 7019, close to Dart shipwreck, São Sebastião Island, Ilhabela, São Paulo State, Brazil, depth 4 m, coll. F. F. Cavalcanti, 30/XI/2008 . UFRJPOR7056, Costa do Aquário , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 12 m, coll. F. F. Cavalcanti , V. Padula & R. Berlinck , 05/XII/2008 .

Comparative material examined: Holotype of Paraleucilla perlucida —UFRJPOR4961, Botinas Islands , Angra dos Reis, Rio de Janeiro, Brazil ( -23.05000, -44.32833), depth 3 m, coll. M. Klautau, 11/VI/2005. UFRJPOR4928, Botinas Islands, Angra dos Reis, Rio de Janeiro, Brazil, depth 3 m, coll. M. Klautau & E. Lanna, 17/IV/2004. GoogleMaps

Colour: Beige in life and beige or white in ethanol ( Fig. 17A, B, C View FIGURE 17 ).

Morphology and anatomy: Sponge body highly variable in morphology, from oval ( Fig. 17A View FIGURE 17 ) to tubular ( Fig. 17B View FIGURE 17 ) or almost spherical in shape ( Fig. 18A View FIGURE 18 ), with variable hispidation as well, but a single, apical osculum surrounded by a crown of trichoxeas is present in all specimens. The external surface varies from slightly hispid, when the protruding diactines are rare or broken, to quite hispid when these spicules are abundant ( Fig. 17C View FIGURE 17 ). The atrial cavity is wide and hispid ( Fig. 17A View FIGURE 17 ). Aquiferous system leuconoid.

The oscular crown of trichoxeas is supported by tetractines and some oblique diactines. The cortical skeleton is composed of the basal system of large tetractines and triactines, the latter variable in shape, size, and abundance, depending on the specimen and on the region of the body. For instance, in the specimen MNRJ30133, cortical triactines seem to be concentrated in the basal region of the body ( Fig. 18B View FIGURE 18 ), whereas in the specimen MNRJ30131 they are much rarer ( Fig. 17D View FIGURE 17 ). Sparse tufts of diactines ( 2–6 in each) also occur in the cortex ( Fig. 17E View FIGURE 17 ), and rare cortical microdiactines were found only in one specimen (MNRJ30133), near its base. The choanosomal skeleton is inarticulate near the surface (outer region) and disorganised below the subatrial skeleton (inner region), what is typical of the genus ( Fig. 17F View FIGURE 17 ). The inner region is supported by large triactines and tetractines similar to those of the subatrial skeleton ( Fig. 17G View FIGURE 17 ), irregularly scattered. Sometimes, there is a second subatrial skeleton, adjacent to the atrial one, composed of triactines and tetractines smaller and thinner than those of the original subatrial skeleton. In specimens with a thicker body wall, this second subatrial skeleton is not evident, consequently, the subatrial triactines II and subatrial tetractines II may be very rare. The atrial skeleton is exclusively composed of tetractines ( Fig. 17H View FIGURE 17 ).

Spicules ( Table 9):

Trichoxeas: Long, very thin and cylindrical, usually broken. Size:>1250.0/7.5 µm.

Diactines: Straight or slightly curved, fusiform and with sharp tips. Most of them were broken ( Fig. 19A View FIGURE 19 ). Size:>780.0/25.0 µm.

Microdiactines: Slightly curved, smooth, fusiform, with both tips sharp. Size: 145.7 (±38.0)/3.9 (±0.7) µm.

Cortical triactines: Sagittal, variable in shape and size. Few are large, robust, with conical actines, being similar to the basal system of the cortical tetractines. Most of them are small, with slightly conical, sharply to bluntly pointed actines, and curved paired actines which are longer than the unpaired one ( Fig. 19B View FIGURE 19 ). Size: paired—292.0 (±35.6)/24.5 (±3.7) µm; unpaired—190.0 (±62.0)/24.0 (±3.8) µm.

Cortical tetractines: Large, sagittal. Basal actines are straight, conical, with sharp tips. The unpaired actine is a little shorter than the paired ones ( Fig. 19C View FIGURE 19 ). The apical actine is long, straight, conical to slightly conical and sharp. Size: paired—454.5 (±97.5)/45.4 (±9.0) µm; unpaired—393.1 (±126.5)/48.5 (±9.9) µm; apical—627.5 (±115.8)/43.5 (±9.2) µm.

Subatrial triactines and tetractines I: Large, sagittal, variable in width. Basal actines are conical to slightly conical and sharp. The unpaired actine is straight and similar to or longer than the paired ones, which are inwardly curved ( Fig. 19D, E View FIGURE 19 ). The apical actine is greatly variable in length, straight, conical and sharp. Triactines size: paired—395.3 (±75.9)/36.8 (±10.0) µm; unpaired—508.0 (±81.9)/39.8 (±8.8) µm. Tetractines size: paired—435.0 (±74.7)/44.0 (±8.7) µm; unpaired—519.7 (±97.6)/47.6 (±9.4) µm; apical—228.3 (±141.3)/40.0 (±7.3) µm.

Subatrial triactines and tetractines II: Small and thin, sagittal. Basal actines are cylindrical and sharp. The unpaired actine is straight and much longer than the paired ones, which are curved ( Fig. 19F View FIGURE 19 ). The apical actine is short, conical and sharp. Triactines size: paired—235.4 (±48.2)/16.0 (±4.3) µm; unpaired—396.4 (±112.7)/18.8 (±4.1) µm. Tetractines size: paired—175.0/7.5 µm; unpaired—250.0/8.8 µm; apical—25.0/5.0 µm.

Atrial tetractines: Slightly sagittal (but strongly sagittal near the osculum). Basal actines are cylindrical and sharp. The unpaired actine is straight and usually shorter than the paired ones, which are slightly curved ( Fig. 19G View FIGURE 19 ). The apical actine is smooth, curved, conical, sharp and shorter than the basal ones. Size: paired—223.6 (±40.8)/10.8 (±1.7) µm; unpaired—160.5 (±83.1)/11.8 (±1.2) µm; apical—85.3 (±15.7)/9.9 (±0.9) µm.

Ecology: Specimens MNRJ30131 and MNRJ30133 were collected in a cave, protected from sunlight, while the other specimens were found exposed to sunlight.

Geographic distribution: São Pedro and São Paulo Islands ecoregion—São Pedro and São Paulo Archipelago ( Cóndor-Luján et al.2019), Brazil.Northeastern Brazil ecoregion— Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas and Bahia states ( Borojević & Peixinho 1976; Chagas 2021), Brazil. Eastern Brazil ecoregion—Vitória-Trindade Seamounts Chain, Espírito Santo State ( Borojević & Peixinho 1976; Chagas 2021), Brazil. Southeastern Brazil ecoregion—Angra dos Reis and Cabo Frio, Rio de Janeiro State ( Borojević & Peixinho 1976; Azevedo & Klautau 2007; Chagas 2021); São Sebastião and Búzios Islands (Ilhabela), São Paulo State (present study), Brazil.

Remarks: The specimens from Ilhabela fit well the description of P. perlucida , with overall similar skeletal composition and spicules shape. Besides, sequences of our specimens grouped with a sequence of P. perlucida from São Pedro and São Paulo archipelago with 100% similarity and high support (BS = 96%) ( Fig. 2 View FIGURE 2 ).

Although most of our specimens do not present microdiactines and subatrial tetractines II, these categories are rare in the holotype, as indicated by the low number of measured spicules in the original description ( Azevedo & Klautau 2007). Regarding spicule dimensions, the specimens MNRJ30131 and MNRJ30133 have larger, more robust spicules, especially cortical tetractines [paired actines: 454.5 (±97.5)/45.4± (9.0) µm, unpaired actine: 393.1 (±126.5)/48.5 (±9.9) µm] and subatrial triactines I [paired actines: 395.3 (±75.9)/36.8 (±10.0) µm, unpaired actine: 508.0 (±81.9)/39.8 (±8.8) µm], compared to the holotype [cortical tetractines—paired actines: 272.0 (±49.0)/28.0 (±4.0) µm, unpaired actine: 246.0 (±49.0)/28.0±7.0 µm; subatrial triactines I—paired actines: 178.0 (±34.0)/14.0 (±3.0) µm, unpaired actine: 270.0 (±34.0)/14.0 (±3.0) µm]. However, we measured these spicule categories in specimen UFRJPOR4928 (from the type locality and examined in the original description) and there was an overlap of spicule size ranges ( Table 9), indicating that the differences in spicule dimensions can be attributed to variability.

Paraleucilla perlucida View in CoL is widely distributed along the Brazilian coast, since specimens from several localities previously identified as Leucilla australiensis View in CoL by Borojević & Peixinho (1976) actually correspond to P. perlucida (Chagas 2021) View in CoL . Indeed, the description and illustrations provided by Borojević & Peixinho (1976) closely match the original description of P. perlucida View in CoL . This wide distribution is further supported by the results of our phylogenetic analysis.

taken in the present work).