Leucaltis nuda, Azevedo, Fernanda, Hajdu, Eduardo, Willenz, Philippe & Klautau, Michelle, 2009

Azevedo, Fernanda, Hajdu, Eduardo, Willenz, Philippe & Klautau, Michelle, 2009, New records of Calcareous sponges (Porifera, Calcarea) from the Chilean coast, Zootaxa 2072, pp. 1-30 : 9-12

Leucaltis nuda sp. nov.

( Figs. 5 A–F, 9C; Table 5)

Type material. IZUA-POR-0117 = MNRJ 10798 (holotype / alcohol). MNRJ 10795 = RBINSc POR 118 and MNRJ 10810 = RBINSc POR 119 (paratypes / alcohol)

Type locality. Reñihue Fjord I, X th Region, Chile.

Material examined. MNRJ 10795; Reñihue Fjord I; collected by Ph.W. & J. Biro; 20 May 2007; - 23.3 m. IZUA-POR-0117 = MNRJ 10798; Reñihue Fjord I; collected by E.H. & Ph.W.; 22 May 2007; - 22 m. MNRJ 10804 = RBINSc POR 120; Reñihue Fjord II; collected by E.H. & Ph.W.; 23 May 2007; - 30 m. MNRJ 10810 = RBINSc POR 121; Reñihue Fjord III collected by E.H. & Ph.W.; 23 May 2007; - 30 m. MNRJ 10846; Reñihue Fjord IV; collected by E.H. & Ph.W.; 25 May 2007; - 31 m.

Colour. White in life and in alcohol.

Etymology. Latin nudus (= naked). Describing the almost absence of the choanosomal and atrial skeletons.

Description. The body of this species is composed of large ramified tubes covered by a thick cortex (0.5 mm) and surrounding a large atrium (0.5 to 3.0 mm) ( Figs. 5 A, 9C). The entire body wall is only 1.0 mm thick. Its consistency is slightly compressible and friable, and the surface is smooth. Oscula are present at the apical region and they do not have any fringe. Choanocyte chambers are elongated and ramified. Oocytes were present in all the collected specimens. The cortical skeleton is well developed, having almost the same thickness as the choanosome, and is composed of very variable tangential triactines. Subcortical large tetractines are present, but they are rare. These spicules project their apical actine into the choanosome, sometimes crossing even the atrial wall ( Fig. 5 B). The choanosomal skeleton may be absent or composed of the same tiny triactines and tetractines that form the atrial skeleton, which can be absent or formed by few triactines and rare tetractines ( Fig. 5 C).

Spicules ( Table 5). Cortical triactine [245.0 (±108.8) / 15.3 (±6.0) µm]: Regular (equiangular and equiradiate). Actines are cylindrical with blunt tips ( Fig. 5 D).

10795, MNRJ 10810).

Spicule Lenght (µm) Width (µm) n min mean s max mean s

IZUA-POR-0117 Cortical triactine 69.3 245.0 108.8 430.9 15.3 6.0 100 Cortical tetractine basal 291.9 417.0 90.6 500.4 30.6 7.9 5 apical 347.5 437.4 46.4 486.5 35.2 7.2 15 Atrial triactine 26.4 33.4 4.1 46.2 5.8 0.8 30

MNRJ 10795 Cortical triactine 115.5 244.9 70.6 399.0 15.7 4.6 100 Cortical tetractine basal 252.0 367.5 79.0 451.5 21.0 4.3 7 apical 262.5 21.0 1 Atrial triactine 23.4 28.7 2.6 33.8 4.9 0.7 20

MNRJ 10810 Cortical triactine 84.0 250.8 83.5 388.5 19.0 5.9 100 Cortical tetractine basal 367.5 455.0 125.3 598.5 43.8 8.0 3 apical 315.0 42.0 1 Atrial triactine 23.1 35.5 8.4 59.4 5.1 1.0 30

All specimens Cortical triactine 69.3 246.9 3.4 430.9 16.7 2.0 - Cortical tetractine basal 252 413.2 43.8 598.5 31.8 11.4 - apical 347.5 338.3 89.7 486.5 32.7 10.7 - Atrial triactine 23.1 32.5 3.5 59.4 5.3 0.5 - Cortical tetractine [basal 417.0 (±90.6) / 30.6 (±7.9) µm, apical 437.4 (±46.4) / 35.2 (±7.2) µm]: Regular (equiangular and equiradiate). Actines are conical with blunt tips ( Fig. 5 E). The apical actine is frequently longer than the basal ones. It is also conical with blunt tip.

Choanosomal and atrial triactine [33.4 (±4.1) / 5.8 (±0.8) µm]: Regular (equiangular and equiradiate). Actines are conical with blunt tips ( Fig. 5 F).

Choanosomal and atrial tetractine: Regular (equiangular and equiradiate). Actines are conical with blunt tips. The apical actine is thicker than the basal ones. It is conical, smooth, blunt and slightly curved at the end.

Ecology. Specimens were found on vertical hard substrate from -22 to - 31m.

Remarks. The genus Leucaltis was proposed by Haeckel (1872) for the specimen Leucaltis clathria Haeckel, 1872 and redefined by Dendy & Row (1913), which concluded that it was a monospecific genus. Since then, L. clathria has been considered to be cosmopolitan, being present in all tropical seas, from the type locality, Florida, to Australia. In 1929, Hôzawa described another species for the genus, L. tenuis , a species from Japan. Although this species has not been recollected since its original description, it was mentioned by Tanita (1943) and Burton (1963) as a valid species. In the revision of the subclass Calcinea ( Borojevic et al. 1990), however, L. tenuis was probably overlooked and L. clathria was considered again “the unique species” of the genus, which was stated again in the Systema Porifera ( Borojevic et al. 2002).

Leucaltis nuda sp. nov. is the third species of the genus. This new species is more similar to L. clathria , but it can be differentiated mainly by the choanosomal and atrial skeletons, which are almost absent in L. nuda sp. nov. Moreover, in our species, the spicules of the atrial skeleton (triactines and tetractines) are equiradiate and equiangular, and not sagittal as in L. clathria . L. nuda sp. nov. can be differentiated from L. tenuis by the atrial skeleton, which is almost absent in the new species and “fairly well developed” in L. tenuis ( Hôzawa, 1929) . Besides, even when the atrial skeleton is present in L. nuda sp. nov., the triactines are much smaller (23 to 59 / 5.5 µm) than in L. tenuis (200 to 550 / 16 to 40 µm).

The original measurements of spicules of L. clathria and L. tenuis are given here. L. clathria – cortical triactine: 400–600/30–50 µm, cortical tetractine: basal 800–1,200/100–150 µm, apical approximately with the same length, sagittal choanosomal and atrial triactine and tetractine: paired 50–70/2–3 µm, unpaired 30–40/ 2–3 µm, apical usually as long as the basal actines, rare regular and subregular choanosomal and atrial triactine and tetractine: 40–70/1–2 µm; L. tenuis —cortical triactine 300–570/20–650 µm, cortical tetractine: basal 250–700/30–80 µm, apical 400–970 µm long, atrial triactine and tetractine: 200–550/16–40 µm; L. nuda sp. nov. —cortical triactine 69.3–430.9/15.3 (±6) µm, cortical tetractine: basal 291.9–500.4/30.6 (±7.9) µm, apical 347.5–486.5 µm long, atrial triactine and tetractine: 26.4–46.2/5.8 (±0.8) µm.

Figures

FIGURE 5. External and internal morphology of Leucaltis nuda sp. nov.; A – Fixed specimen; B—Transversal section of tube wall (cx: cortex, cn: choanosome, at: atrium); C—Detail of the atrial skeleton (at: atrium); D—Cortical triactines; E—Cortical tetractine; F—Atrial triactine.