Paraleucilla magna Klautau, Monteiro & Borojević, 2004

Paraleucilla magna Klautau, Monteiro & Borojević, 2004 View in CoL

( Figs. 14–16 View FIGURE 14 View FIGURE 15 View FIGURE 16 ; Table 8)

Synonyms: Leucilla? australiensis — Muricy et al. 1991: 1187. Leucilla aff. australiensis — Nassar & Silva 1999: 200. Paraleucilla magna — Klautau et al. 2004: 03; Longo et al. 2004: 440; Muricy & Hajdu 2006: 87; Longo et al. 2007: 1751; Junqueira et al. 2009: 157; Zammit et al. 2009: 135; Guardiola et al. 2012: 72; Longo et al. 2012: 2; Canning-Clode et al. 2013: 263; Cvitković et al. 2013: 95; Bertolino et al. 2014: 109; Dailianis et al. 2016: 610; Guardiola et al. 2016: 123; Mačić & Petović 2016: 65; Marra et al. 2016: 4; Klautau et al. 2016: 37; Topaloğlu et al. 2016: 53; Gerovasileiou et al. 2017: 368; Ulman et al. 2017: 35; Bachetarzi et al. 2019: 41; Chebaane et al. 2019: 620; Sghaier et al. 2019: 37; Bensari et al. 2020: 397; Cavalcanti et al. 2020: 3574; Evcen & Çınar 2020: 151; Katsanevakis et al. 2020: 173; Tamburini et al. 2021: 6; Santín et al. 2024: 8; Lopes et al. 2025: 189.

Type locality: Praia Vermelha , Rio de Janeiro, Rio de Janeiro State, Brazil .

Material examined: MNRJ2996 View Materials , between São Pedro and Veloso , São Sebastião Island, Ilhabela, São Paulo State, Brazil, depth 6–10 m, coll. E. Hajdu, 06/I/2000 . MNRJ5831 View Materials , Alcatrazes Archipelago , São Sebastião, São Paulo State, Brazil, depth 16 m, coll. U. Pinheiro & M. Carvalho, 03/ V /2002. MNRJ5921 View Materials , Alcatrazes Archipelago , São Sebastião, São Paulo State, Brazil, depth unknown, coll. U. Pinheiro & M. Carvalho, 02/ V /2002. UFRJPOR6893, Saquinho da Sumítica , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 9 m, coll. F. F. Cavalcanti, 01/XII/2008 . UFRJPOR6926, Parcel da Coroa , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 6 m, coll. F. F. Cavalcanti & V. Padula , 02/XII/2008 . UFRJPOR6936, 6937, Sumítica Island , Ilhabela, São Paulo State, Brazil, depth 9 m, coll. F. F. Cavalcanti , V. Padula & L. Kremer, 02/XII/2008 . UFRJPOR6999, Parcel da Pedra Lisa , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 7 m, coll. F. F. Cavalcanti, 01/XII/2008 . UFRJPOR7032, Saquinho da Sumítica , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 9 m, coll. F. F. Cavalcanti, 01/XII/2008 . UFRJPOR7055, Costa do Aquário , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 12 m, coll. F. F. Cavalcanti , V. Padula & R. Berlinck , 05/XII/2008 . UFRJPOR7058, Coroa , Búzios Island, Ilhabela, São Paulo State, Brazil, depth 15 m, coll. F. F. Cavalcanti & V. Padula , 05/XII/2008 . UFRJPOR9302, Alcatrazes Archipelago , São Sebastião, São Paulo State, Brazil, depth 5–7 m, coll. S. López, 18/III/2023 . UFRJPOR9303, Alcatrazes Archipelago , São Sebastião, São Paulo State, Brazil, depth 5–7 m, coll. S. López, 05/IV/2023 .

Colour: Beige in life and beige or white in ethanol ( Fig. 14A–C View FIGURE 14 ).

Morphology and anatomy: Sponge of tubular or massive body, with irregular, folded surface ( Fig. 14A–C View FIGURE 14 ). Oscula are apical and naked ( Fig. 14D View FIGURE 14 ). Both the external and atrial surfaces are smooth, and the consistency is friable. Aquiferous system leuconoid, with spherical or slightly elongated choanocyte chambers and several subcortical lacunae ( Fig. 14E View FIGURE 14 ).

The oscular margin is formed by T-shaped triactines ( Fig. 14D View FIGURE 14 ). The cortical skeleton is composed of numerous triactines and tetractines ( Fig. 15A View FIGURE 15 ), with apical actines pointing to the atrium, occasionally crossing it. In most specimens, the choanosomal skeleton is inarticulate near the surface (outer region) and disorganised below the subatrial skeleton (inner region), a typical feature of the genus. In the disorganised layer, scattered triactines and tetractines, similar to the subatrial ones, are present, with the tetractines being more abundant. However, in some specimens, there is no disorganised zone and the choanosomal skeleton remains inarticulate, formed by the apical actine of the cortical tetractines and the unpaired actine of the subatrial triactines and tetractines ( Fig. 15B–D View FIGURE 15 ). The atrial skeleton is formed by numerous triactines and, in some specimens, few tetractines ( Fig. 15E–G View FIGURE 15 ).

Spicules ( Table 8):

Cortical triactines: Sagittal. Actines are cylindrical to slightly conical, with blunt to sharp tips. The paired actines are straight or a little undulated and longer than the unpaired one ( Fig. 16A View FIGURE 16 ). Size: paired—225.0 (±31.7)/13.0 (±2.2) µm; unpaired—224.0 (±43.7)/13.5 (±2.2) µm.

Cortical tetractines: Large, sagittal. Basal actines are straight and conical, with sharp tips. The paired actines are straight or slightly curved and longer than the unpaired one ( Fig. 16B View FIGURE 16 ). The apical actine is long, straight, conical to slightly conical, with sharp to blunt tips. Size: paired—352.0 (±43.6)/31.0 (±3.8) µm; unpaired—307.5 (±41.0)/30.0 (±3.2) µm; apical—424.5 (±85.4)/30.1 (±7.0) µm.

Subatrial triactines: Sagittal. Actines are conical to slightly conical, with sharp tips. The unpaired actine is straight and only slightly longer than the paired ones, which are inwardly curved ( Fig. 16C View FIGURE 16 ). Size: paired—271.4 (±55.3)/19.3 (±2.9) µm; unpaired—291.4 (±38.2)/19.2 (±2.7) µm.

Subatrial tetractines: Sagittal and as large and robust as the cortical tetractines. Basal actines are straight and conical, with sharp tips. The unpaired actine is usually a little longer than the paired ones ( Fig. 16D View FIGURE 16 ). The apical actine is often longer than the basal ones and slightly curved, conical, with sharp to blunt tips. Size: paired—269.3 (±61.7)/22.3 (±6.2) µm; unpaired—283.5 (±55.4)/25.3 (±5.5) µm; apical—243.8 (±74.4)/21.9 (±6.7) µm.

Atrial triactines and tetractines: Sagittal. Basal actines are slightly conical, with sharp tips. The paired actines are straight or curved, sometimes undulated, while the unpaired actine is straight, shorter and thinner than the paired ones ( Fig. 16E–G View FIGURE 16 ). The apical actine of the tetractines is short, straight, conical, sharply pointed, and smooth or spined at the tip ( Fig. 16F, G View FIGURE 16 ). Triactines size: paired—256.3 (±40.7)/17.4 (±2.2) µm; unpaired—187.8 (±68.0)/16.3 (±1.9) µm. Tetractines size: paired—235.8 (±50.0)/16.1 (±2.4) µm; unpaired—170.0 (±66.1)/15.8 (±2.2) µm; apical—49.1 (±11.6)/16.1 (±2.6) µm.

Ecology: Specimen MNRJ2996 was growing attached to a fishing line, with several polychaete tubes on its surface. Specimen MNRJ5831 was associated with a branching bryozoan colony.

Geographic distribution: Eastern Brazil ecoregion— Espírito Santo State ( Lopes et al. 2025), Brazil. Southeastern Brazil ecoregion—Angra dos Reis, Arraial do Cabo, Sepetiba Bay, Itacuruçá, Niterói and Rio de Janeiro, Rio de Janeiro State ( Muricy et al. 1991; Klautau et al. 2004; Muricy & Hajdu 2006; Junqueira et al. 2009; Cavalcanti et al. 2020); São Sebastião, Búzios and Sumítica Islands (Ilhabela) and Alcatrazes Archipelago (São Sebastião), São Paulo State ( Klautau et al. 2004; Muricy & Hajdu 2006; Junqueira et al. 2009; Cavalcanti et al. 2020; present study); Florianópolis and Moleques do Sul Islands, Santa Catarina State ( Junqueira et al. 2009; Cavalcanti et al. 2020), Brazil. Azores Canaries Madeira ecoregion— Azores Archipelago and Madeira Island ( Canning-Clode et al. 2013; Guardiola et al. 2016; Santín et al. 2024), Portugal. South European Atlantic Shelf ecoregion— Portugal ( Guardiola et al. 2016). Alboran Sea ecoregion— Algeria ( Bensari et al. 2020). Western Mediterranean ecoregion— Spain, Italy, Algeria and Tunisia ( Longo et al. 2007; Bertolino et al. 2014; Dailianis et al. 2016; Marra et al. 2016; Ulman et al. 2017; Bachetarzi et al. 2019; Katsanevakis et al. 2020; Tamburini et al. 2021). Tunisian Plateau/Gulf of Sidra ecoregion— Tunisia and Libya ( Chebaane et al. 2019; Sghaier et al. 2019; Katsanevakis et al. 2020). Ionian Sea ecoregion— Malta and Italy ( Longo et al. 2007; Zammit et al. 2009; Ulman et al. 2017). Adriatic Sea ecoregion— Italy, Slovenia, Croatia and Montenegro ( Longo et al. 2007; Cvitković et al. 2013; Klautau et al. 2016; Mačić & Petović 2016; Cavalcanti et al. 2020; Katsanevakis et al. 2020). Aegean Sea ecoregion— Turkey (Sea of Marmara) and Greece ( Topaloğlu et al. 2016; Gerovasileiou et al. 2017; Ulman et al. 2017; Evcen & Çınar 2020). Levantine Sea ecoregion— Cyprus and Egypt ( Ulman et al. 2017; Sghaier et al. 2019).

Remarks: We found for the first time a few tetractines in the atrial skeleton of some specimens of P. magna (MNRJ2996, MNRJ5831, MNRJ5921). Initially we thought they could be Leucilla , as they did not present the disorganised choanosomal zone characteristic of Paraleucilla . However, we also found some tetractines in the atrial skeleton of specimens of P. magna from the Eastern Mediterranean (SEP, pers. obs.). In that study, DNA sequences were successfully obtained from two specimens with atrial tetractines, only one of which exhibited the disorganised zone. Both specimens clustered with sequences of P. magna with 100% similarity. Thus, we interpret the presence of a few atrial tetractines as part of the intraspecific variability of P. magna , as well as the lack of the disorganised zone (the latter previously shown by Lanna et al. 2017).