Leucandra serrata, 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 : 11-16

Leucandra serrata sp. nov.

TYPE MATERIAL—UFRJPOR 4878 (holotype / alcohol). Angra dos Reis (Bonfim Island). Collected by M. Klautau (5 April 2003), 2 m depth. UFRJPOR 4879, UFRJPOR 4881 (paratypes / alcohol). Angra dos Reis (Botinas Islands). Collected by M. Klautau (5 April 2003), 2 m depth.

LOCALITY—Bonfim Island, Angra dos Reis, Rio de Janeiro, Brazil.

MATERIAL EXAMINED—UFRJPOR 4880, UFRJPOR 4882. Ilha do Bonfim. Collected by M. Klautau (6 April 2003), 2 depth, UFRJPOR 4883, UFRJPOR 4884, UFRJPOR 4885, UFRJPOR 4886, 4887, UFR­ JPOR 4888, UFRJPOR 4889, UFRJPOR 4890, UFRJPOR 4891, UFRJPOR 4892, UFRJPOR 4893, UFR­ JPOR 4894. Angra dos Reis (Botinas Islands). Collected by M. Klautau & E. Lanna (17 April 2004), 3 depth, UFRJPOR 4895, UFRJPOR 4896. Bonfim Island. Collected by F. Azevedo (15 August 2004), 1 m depth.

COLOUR—White in life and in alcohol.

ETYMOLOGY—Latin serratus (= jagged). It describes a special jagged microdiactine present in the cortex.

DESCRIPTION—This sponge has a friable globular body ( Fig. 5 A). The holotype is 17 x 17 x 17 mm. The external surface is slightly hispid, mainly near the osculum, where there are large diactines protruding through the surface. Microdiactines are also present on the surface. The osculum is apical, 10 mm high, and it is surrounded by a fringe of trichoxeas. Some of the specimens analysed showed naked oscula. The wall of the sponge is 4 mm in its greatest thickness. The atrium is located below the osculum, and it is hispid due to the presence of the apical actines of the atrial tetractines. Few canals of variable sizes reach the atrial cavity, as the aquiferous system is leuconoid. The cortical skeleton is formed of tangentially disposed triactines, and perpendicular large diactines ( Fig. 5 B) and microdiactines ( Fig. 5 C). The triactines of the choanosome have no special organization ( Fig. 5 D). In that region there are canals surrounded by tetractines, which project their apical actines into them ( Fig. 5 E). Few triactines can also be observed surrounding these canals. The atrial skeleton is composed of tetractines and few triactines ( Fig. 5 F).

SPICULES ( Table 7). Diactines: Large, almost fusiform. Occasionally, the side that penetrates the body is thicker ( Fig. 5 G).

Microdiactines: Short and thin, with one jagged tip and the other (which penetrates the body) smooth and sharp. Sometimes, both tips are smooth ( Fig. 5 H).

Cortical triactines: Almost regular. Actines are slightly conical to cylindrical and sharp. The paired actines are longer than the unpaired one, and their size is very variable ( Fig. 5 I).

Choanosomal triactines: Almost regular. Actines are conical and sharp, and the paired actines are longer than the unpaired one ( Fig. 5 J).

Tetractines of the canals: Sagittal. Actines are slightly conical and sharp. The paired actines are longer than the unpaired one. The apical actine is smooth, slightly curved and sharp ( Fig. 5 K).

Atrial tetractines: Sagittal. Actines are slightly conical and sharp. The unpaired actine is shorter than the paired ones. The apical actine is smooth, conical, sharp and slightly curved ( Fig. 5 L).

Length Width

(µm) (µm)

Spicule Actines min mean S max mean S n Diactines 360.0 806.0 299.9 1,300.0 31.0 7.4 10 Microdiactines 87.0 111.0 17.9 138.0 1.5 0.0 0 8 Cortical triactines Paired 106.0 197.0 40.0 285.0 7.0 1.0 30 Unpaired 80.0 155.0 48.0 266.0 7.0 1.0 30 Choanosomal triactines Paired 234.0 420.0 69.0 523.0 30.0 6.0 30 Unpaired 125.0 279.0 63.0 421.0 30.0 6.0 30 Choanosomal tetractines (canals) Paired 125.0 179.0 29.0 277.0 8.0 1.0 30 Unpaired 99.0 158.0 44.0 293.0 8.0 1.0 30 Apical 38.0 61.0 11.0 87.0 5.0 1.0 30 Atrial tetractines Paired 133.0 205.0 39.0 274.0 7.0 0.8 28 Unpaired 49.0 93.0 27.0 141.0 7.0 1.0 28 Apical 30.0 53.0 16.0 95.0 4.0 0.4 28 REMARKS—Eight species of Leucandra have been cited for the Brazilian coast. L. barbata (Duchassaing & Michelotti, 1864) , L. caminus Haeckel, 1872 , L. caminus var. crassior ( Ridley, 1881) , L. sacculata ( Carter, 1890) , L. armata Urban, 1908 , L. crosslandi Thacker, 1908 , and L. hentschelii Brondsted, 1929 were cited to the Northeast of Brazil ( Carter 1890, Borojevic & Peixinho 1976), while L. globosa Tanita, 1943 was cited to the Southeast ( Muricy et al. 1991). L. serrata sp. nov. differs from the original descriptions of L. barbata from the Caribbean, L. caminus from the North Atlantic, and L. caminus var. crassior and L. sacculata from Brazil mainly by the absence of microdiactines in these four species. Comparing our species to the original description of L. armata from the South Africa, it differs by the shape of the diactines, which is fusiform in L. serrata sp. nov. and arrow­headed in L. armata . Moreover, L. armata has no microdiactines. In relation to the original description of L. hentschelii from the South Africa, our species can be distinguished by the absence of diactines in that species. The most similar species to L. serrata sp. nov. is L. crosslandi from the Cape Verde Islands. Nevertheless, we decided to distinguish them as the size of their spicules is very different ( Table 8). Besides, the microdiactines of L. crosslandi are smooth and not jagged as in L. serrata sp. nov.

Reading the descriptions made by Borojevic & Peixinho (1976) of Leucandra species from Brazil, and comparing them to the original descriptions of L. barbata , L. caminus , L. armata , L. hentschelii , and L. crosslandi , we were not convinced of their identifications. Hence, we also decided to compare L. serrata sp. nov. to the descriptions made by those authors, and none of them matched the specimens of Ilha Grande Bay. L. barbata sensu Borojevic & Peixinho (1976) has cortical triactines similar to their choanosomal triactines, while L. serrata sp. nov. has very distinct triactines, in shape and size. L. caminus sensu Borojevic & Peixinho (1976) has diactines that never protrude through the surface as in L. serrata sp. nov. L. armata sensu Borojevic & Peixinho (1976) shows triactines and tetractines forming the choanosomal skeleton, while L. serrata sp. nov. has only triactines. L. hentschelii , again sensu Borojevic & Peixinho (1976), does not have diactines. L. crosslandi sensu Borojevic & Peixinho (1976) is very similar to L. serrata sp. nov. The composition of the skeleton of L. crosslandi sensu Borojevic & Peixinho (1976) is identical to that of L. serrata sp. nov., however the size of the spicules is very different ( Table 9). Diactines in L. serrata sp. nov. are much larger (360.0–1,300.0 / 31.0) than in L. crosslandi sensu Borojevic & Peixinho (1976) (maximum 200 μm), and all the other spicules are smaller in our species. L. globosa was only cited in a list of species from Arraial do Cabo ( Muricy et al. 1991), consequently, we could not compare it with our species. Nonetheless, comparing the specimens of the Ilha Grande Bay to the original description of L. globosa from Japan made by Tanita (1943), our species are very similar, but differs by the spicule size and by the shape of the diactines. All the spicules of L. globosa are larger ( Table 10) than those of L. serrata sp. nov., moreover the diactines of our species have one tip different from the other. We have also compared our species with the specimens from Arraial do Cabo that were previously identified as L. globosa and cited by Muricy et al. (1991), and our species is morphologically very different from them.

Length Width (µm) (µm)

Spicule Actines

Diactines 1,000–1,500 80–100 Microdiactines 150 3.5 Cortical triactines Paired 180 12 Unpaired 70 12 Choanosomal triactines 250 35 Atrial tetractines Paired 150 20

Apical 50–75

Length Width (µm) (µm)

Spicule Actines

Diactines 200

Microdiactines 70–100 3–5 Cortical triactines Paired 200–250 14 Unpaired 215–300 12–18 Choanosomal triactines 350–1,000 40–80 Atrial tetractines Paired 140–250 10–15 Unpaired 150–300 10–15 Apical 30–60

Length Width (µm) (µm)

Spicule Actines

Diactines 630–1500 45–60 Microdiactines 85 3

Cortical triactines Paired 400–450 45–54 Unpaired 300–380 45–54 Choanosomal triactines Paired 350–500 22–33 Unpaired 360–400 22–33 Choanosomal tetractines (canals) Paired 130–190 18 Unpaired 160–220 18 Apical 70–90 15 Subatrial triactines and tetractines Paired 140–210 16–20 Unpaired 200–360 16–20 Apical 80 13–16 Atrial tetractines Paired 220–280 18 Unpaired 200–260 18 Apical 200–420 15–18

Figures

FIGURE 5. External and internal morphology of Leucandra serrata sp. nov. A—Preserved holotype; B—Cross­section of the choanosome showing the perpendicular diactines (arrow); C—Detail of the cortex with microdiactines protruding through the surface (arrow); D—Cross­section of the choanosome with a canal; E—Cross­section of a canal with apical actines of tetractines; F—Cross­section of the atrium with apical actines of tetractines protruding into it.