Leucetta purpurea, Leocorny, Pedro, Alencar, Aline, Fromont, Jane & Klautau, Michelle, 2016

Leocorny, Pedro, Alencar, Aline, Fromont, Jane & Klautau, Michelle, 2016, New Leucettidae de Laubenfels, 1936 (Porifera, Calcarea) from Western Australia, Zootaxa 4175 (4), pp. 319-334 : 324-326

Leucetta purpurea sp. nov.

Etymology. From the Latin adjective purpureus, meaning purple, for the colour of the species in ethanol.

Diagnosis. Species with a reduced atrium and a conspicuous cortical reticulation of triactines. The skeleton is composed of tripods and one category each of triactine and tetractine.

Type material. Holotype, WAM Z31426; 30º20.36’S, 114º58.81’E Escape Island , Jurien Bay, Western Australia ; station: JWAM06/T2; depth: 12–13 meters; collectors: Fromont, J.; Titelius, M. A.; Whisson, C. S. & Moore, G.I.; date: 01/May/2005. Fragment from Holotype deposited under UFRJPOR 7255.

Type locality. Escape Island , Jurien Bay, Western Australia, Australia.

Description. Sponge purple in ethanol with a massive form (1.9 cm x 1.8 cm) and a single osculum in the apical region (0.1 cm in diameter) ( Figure 3 A). The surface is smooth but is rough to the touch. The atrial cavity is reduced to exhalant canals connected to the osculum. The aquiferous system is leuconoid.

The skeleton is disorganized and composed of tripods, triactines, and tetractines. The cortical skeleton has huge tripods arranged tangentially to the surface and triactines organised in a conspicuous reticulation ( Figure 3 B, 3C). No subcortical lacunae were present. The choanosomal skeleton is composed of triactines and tetractines. The tetractines mainly surround the canals with their apical actines pointing inwards ( Figure 3 D, 3E). Spicules. ( Table 3). Tripods ( Figure 3 F): regular or subregular. Actines are conical and curved with blunt tips (625–785–1125 µm / 100–166–225 µm).

Triactines ( Figure 3 G): regular, or sagittal when forming the cortical reticulation. Actines are conical with blunt tips (72–121–153 µm / 10–17–23 µm).

Length (µm) Width (µm)

Spicule Actine Min Mean sd Max Min Mean sd Max N Tripods 625.0 785.0 120.4 1125.0 100.0 166.3 28.7 225.0 20 Triactines 72.5 121.0 26.1 152.5 10.0 16.7 4.3 22.5 20 Tetractines Basal 100.0 131.4 18.5 160.0 12.5 16.8 2.4 20.0 20

Apical 40.0 51.8 10.8 77.5 5.0 7.2 2.0 11.2 20 Tetractines ( Figure 3 H): regular. The apical and basal actines are conical or slightly conical with blunt tips (basal: 100–131–160µm / 13–17–20 µm; apical: 40–52–78 µm / 5–7–11 µm).

Remarks. Leucetta insignis Row & Hôzawa, 1931 , from Australia, is the only species within Leucetta that has the same spicule composition as L. purpurea sp. nov., however, the new species has longer and thicker tripods ( L. insignis : 200–260 µm / 30–60 µm versus L. purpurea sp. nov.: 625–1125 µm / 100–225 µm). Furthermore, L. purpurea sp. nov. is the only species in the genus with a purple colour in ethanol, although more specimens should be collected to confirm the constancy of this character.

Figures

FIGURE 3. Leucetta purpurea sp. nov. (WAM Z 31426, holotype). (A) Preserved specimen. (B) Tangential section of the cortical skeleton. (C) Detail of the cortical reticulation. (D) Cross-section showing cortex (ctx) and canals (ch). (E) Detail of a hispid canal (ch). (F) Tripod. (G) Triactine. (H) Tetractine.