Paraleucilla perlucida, Azevedo, Fernanda & Klautau, Michelle, 2007

Azevedo, Fernanda & Klautau, Michelle, 2007, Calcareous sponges (Porifera, Calcarea) from Ilha Grande Bay, Brazil, with descriptions of three new species, Zootaxa 1402, pp. 1-22 : 7-11

Paraleucilla perlucida sp. nov.

TYPE MATERIAL—UFRJPOR 4961 (holotype / alcohol). Angra dos Reis (Botinas Islands). Collected by M. Klautau (11 June 2005), 3 m depth. UFRJPOR 4925, 4930 (paratypes / alcohol). Angra dos Reis (Botinas Islands). Collected by M. Klautau & E. Lanna (17 April 2004), 3 m depth.

TYPE LOCALITY—Botinas Islands, Angra dos Reis, Rio de Janeiro, Brazil.

MATERIAL EXAMINED—UFRJPOR 4897, UFRJPOR 4898, UFRJPOR 4899, UFRJPOR 4900, UFR­ JPOR 4901, UFRJPOR 4902, UFRJPOR 4903, UFRJPOR 4914, UFRJPOR 4928, UFRJPOR 4929, UFR­ JPOR 4931, UFRJPOR 4934. Angra dos Reis (Botinas Islands). Collected by M. Klautau & E. Lanna (17 April 2004), 3 m depth. UFRJPOR 4936. Angra dos Reis (Bonfim Island). Collected by F. Azevedo (16 October 2004), 1 m depth.

COLOUR—Specimens of this species are white in life and in alcohol.

ETYMOLOGY—Latin perlucidus (= very bright). Derived from its bright surface.

DESCRIPTION—The holotype is 12 x 8 x 5 mm. The body is elongate and oval, with apical osculum ( Fig. 4 A). Frequently each osculum is surrounded by a fringe of trichoxeas. Nevertheless, some specimens do not possess any fringe. Below each osculum there is an atrium with few canals. The aquiferous system is leuconoid and the choanocyte chambers are spherical. Diactines protrude through the surface ( Fig. 4 B). The cortical skeleton is composed of sagittal triactines and tetractines, which lay tangentially to the surface ( Fig. 4 C). The tetractines are large and their basal actines are almost equiangular. The apical actine is longer than the basal ones, and crosses the choanosome. It runs parallel to the unpaired actine of the subatrial tetractines and triactines, which points to the surface. The skeleton is typical of the genus, being inarticulate near the surface (outer region) and without organization below the subatrial skeleton (inner region) ( Fig. 4 D). Consequently, the subatrial skeleton is not adjacent to the atrial skeleton. Below it (inner region), there are scattered large tetractines and some triactines similar to those of the subatrial skeleton. Occasionally, a second subatrial skeleton is present (subatrial II skeleton), adjacent to the atrial one ( Fig. 4 E). This subatrial II skeleton is composed of triactines and tetractines smaller than those of the subatrial skeleton. When the body wall is thin, the skeleton is inarticulate. The atrial skeleton is composed of sagittal tetractines, and their apical actine penetrates the atrium ( Fig. 4 F).

SPICULES ( Table 5). Diactines: They are cylindrical, straight, with sharp tips. These spicules are rare and disposed in tufts of two to six spicules. Their size is very variable ( Fig. 4 G).

Cortical triactines: Sagittal. They lay tangentially to the surface and their actines are conical with sharp tips ( Fig. 4 H).

Cortical tetractines: Sagittal. Their basal actines are conical, straight, with sharp tips. The apical actine is also conical, straight and sharp at the end. It is longer than the basal ones ( Fig. 4 I).

Subatrial triactines and tetractines: Sagittal. Actines are conical, straight and sharp. The paired actines are slightly curved, and the apical actine of the tetractines is shorter than the basal ones ( Fig. 4 J and K). Subatrial II skeleton (triactines II and tetractines II): Sagittal. Actines are slightly conical, straight and sharp. The unpaired actine is longer than the paired ones. The apical actine of the tetractines is very short, conical and sharp ( Fig. 4 L and M).

Atrial tetractines: Sagittal. Actines are conical, sharp, and the paired actines are longer than the unpaired one. The apical actine is straight or slightly curved, smooth, conical and sharp ( Fig. 4 N).

Length Width

(µm) (µm)

Spicule Actines min mean S max mean S n

Microdiactines 87.5 89.1 4.4 100.0 4.1 0.9 8

Diactines 175.0 303.6 127.4 562.5 11.8 1.2 7

Cortical triactines Paired 188.0 250.0 42.0 363.0 24.0 5.0 30 Unpaired 150.0 218.0 37.0 300.0 26.0 5.0 30

Cortical tetractines Paired 163.0 272.0 49.0 350.0 28.0 4.0 30 Unpaired 163.0 246.0 49.0 400.0 28.0 7.0 30 Apical 238.0 219.0 61.0 475.0 29.0 4.0 30

Subatrial tetractines Paired 213.0 294.0 46.0 375.0 30.0 6.0 30 Unpaired 150.0 261.0 64.0 400.0 30.0 5.0 30 Apical 139.0 323.9 115.4 514.3 29.2 7.2 10

Subatrial triactines Paired 125.0 178.0 34.0 263.0 14.0 3.0 30 Unpaired 213.0 270.0 34.0 350.0 14.0 3.0 30

Subatrial triactines II Paired 141.9 180.2 30.2 227.7 11.7 2.4 10 Unpaired 237.6 276.2 32.2 330.0 13.4 3.5 10

Subatrial tetractines II Paired 115.5 179.9 43.3 250.8 8.9 1.4 10 Unpaired 191.4 240.2 35.6 277.2 9.9 1.1 10

Atrial tetractines Paired 113.0 179.0 33.0 263.0 10.0 3.0 30 Unpaired 75.0 140.0 38.0 200.0 10.0 3.0 30 Apical 46.0 68.0 13.0 89.0 7.0 1.0 30 REMARKS—There are six species currently described in the genus Paraleucilla : P. cucumis ( Haeckel 1872) , P. saccharata ( Haeckel 1872) , P. crosslandi (Row 1909) , P. proteus ( Dendy 1913) , P. princeps (Row & Hôzawa 1931) , and P. magna Klautau et al. 2004 . Except for P. magna , which was originally described from Rio de Janeiro, Brazil, the others show an Indo­Pacific distribution, particularly from the Australian coast ( Klautau et al. 2004). P. perlucida sp. nov. can be easily distinguished from P. magna by the presence of tetractines forming the atrial skeleton, while P. magna has triactines in the atrial skeleton.

Comparing P. perlucida sp. nov. with the other species of the genus, we consider that P. princeps is the most similar species. However, they can be distinguished by the size of their spicules ( Table 6) and by the absence of trichoxeas in our species. The diactines of P. perlucida sp. nov. are shorter and thicker (303.6 / 11.8 µm) than those of P. princeps (1,800.0 / 4.0 µm), the subatrial tetractines are longer and thicker in our species (294.0 / 30.0 µm) than in P. princeps (120.0–200.0 / 12.0–18.0 µm), and the apical actines of the atrial tetractines of P. perlucida sp. nov. are much shorter and thinner (46.0–89.0 / 7.0 µm) than those of P. princeps (180.0–450.0 / 8.0–12.0 µm).

In relation to the other species, P. perlucida sp. nov. differs from P. c u c u m i s and P. saccharata by the presence of tetractines in the atrial skeleton of the former. Comparing P. perlucida sp. nov. with P. crosslandi and P. proteus , it can be distinguished by the presence of diactines in our species, which are absent in P. crosslandi and P. proteus .

Length Width (µm) (µm)

Spicule Actines

Trichoxeas 300–600 2–4 Diactines 1,800 4.0 Cortical triactines Paired 200 12–16 Unpaired 240 12–16 Subcortical tetractines Paired 180 10–20 Unpaired 260 12–20 Apical 180–280 12–20 Choanosomal tetractines Paired 120–200 12–18 Unpaired 200–260 12–18 Apical 40–60

Subatrial tetractines Paired 120–200 12–18 Unpaired 200–260 12–18 Apical 40–60

Atrial tetractines Paired 100–200 10–12 Unpaired 140–230 10–12 Apical 180–450 8–12

Figures

FIGURE 4. External and internal morphology of Paraleucilla perlucida sp. nov. A—Preserved holotype; B—Cross­section showing the cortex and a tuft of diactines (arrow); C—Tangential section of the cortex; D—Cross­section of the choanosome with the outer region (arrow 1) and inner region (arrow 2); E—Cross­section showing the subatrial skeleton (arrow 1) and the subatrial II skeleton (arrow 2); F—Cross­section of the atrial skeleton showing the apical actine of tetractines protruding into the atrium