Pericharax vallii, 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 : 328-331

Pericharax vallii sp. nov.

Etymology. From the Latin noun vallus (=stake, palisade), for the conspicuous hispid atrial cavity of the species. Diagnosis. Pericharax with conspicuous oscula surrounded by huge tripods and a hispid atrial cavity with a palisade arrangement of apical actines. Skeleton composed of tripods, one category of triactine and two categories of tetractines.

Type material. Holotype, WAM Z45632; from 34º03’00”S, 122º38’00”E Twin Peak, Recherche Archipelago , Western Australia ; station: TPEV; depth: 15 meters. Fragment from Holotype deposited under UFRJPOR 7126. Paratype, WAM Z40489; from 29º18.85”S, 114º54.07”E Jack Reef, Dongara , Western Australia ; station: JWAM31/T1; depth: 6.5 meters; collectors: Fromont, J.; Whisson, C. S. & Moore, G. I.; Date 15/March/2006. Fragment from Paratype deposited under UFRJPOR 7271.

Type locality. Twin Peak , Recherche Archipelago, Western Australia, Australia.

Additional Material Analysed. WAM Z45626=UFRJPOR 7125, from the same locality as the holotype, but station TPEH ; WAM Z40348=UFRJPOR 7742, from the same locality as the paratype, but station JWAM 31 /Q3.

Description. Sponge beige in ethanol, massive (5.7 cm x 5.7 cm), with a conspicuous osculum apically (1 cm in diameter) ( Figure 5 A). The surface is irregular and rough to the touch. The atrial cavity is large and conspicuously hispid ( Figure 5 B). The aquiferous system is leuconoid.

The skeleton is disorganized. The cortical skeleton is composed of huge tripods and triactines with the tripods mainly concentrated near the osculum ( Figures 5 A, 5C). Subcortical lacunae are present. The choanosomal skeleton is composed of triactines and tetractines I. The tetractines I mainly surround the inhalant canals with their apical actines pointing inwards ( Figures 5 D, 5E). Exhalant canals are hispid and surrounded by tetractines II ( Figure 5 F). The atrial skeleton is principally composed of tetractines II forming a conspicuous palisade of apical actines (i.e. a perpendicular arrangement of the apical actines) in the atrial cavity ( Figure 5 F, 5B).

Spicules. ( Table 6). Tripods ( Figure 5 G): regular or subregular (actines with different lengths). Actines are stout and conical with blunt (sometimes rounded) tips (400–798–1050 µm / 150–237–350 µm).

Length (µm) Width (µm)

Spicule Actine Min Mean sd Max Min Mean sd Max n Tripods

WAM Z45632 (H) 450.0 611.0 88.1 700.0 220.0 257.0 21.1 290.0 10 WAM Z40489 (P) 500.0 798.0 151.2 1050.0 150.0 236.8 37.5 350.0 20 Triactines

WAM Z45632 (H) 87.5 118.3 12.3 137.5 12.5 16.8 1.8 20.0 20 WAM Z40489 (P) 97.2 124.9 16.8 165.2 12.2 14.9 2.1 19.4 20 Tetractines I Basal

WAM Z45632 (H) 92.5 116.9 17.8 150.0 11.2 14.4 1.7 17.5 20 WAM Z40489 (P) 94.8 122.1 15.5 170.1 9.7 14.1 2.1 21.9 20

Apical

WAM Z45632 (H) 37.5 60.6 13.4 100.0 5.0 5.8 1.0 7.5 20 WAM Z40489 (P) 15.0 34.3 18.5 87.5 2.5 5.5 1.2 7.5 20 Tetractines II Basal

WAM Z45632 (H) 100.0 144.7 18.3 175.0 17.5 20.9 3.2 27.5 20 WAM Z40489 (P) 120.0 164.7 19.4 200.0 15.0 17.0 1.8 20.0 20

Apical

WAM Z45632 (H) 285.0 422.7 73.7 545.0 25.0 39.2 8.4 55.0 20 WAM Z40489 (P) 280.0 475.5 91.0 725.0 17.5 22.6 2.0 25.0 20 Triactines ( Figure 5 H): regular. Actines are conical with sharp tips (88–144–170 µm / 12–18–22 µm). Tetractines I ( Figure 5 I, left): regular. The basal actines are conical with sharp tips. The apical actines are slightly conical and curved with sharp tips (basal: 97–125–163 µm / 10–14–22 µm; apical: 15–61–100 µm / 3–6–8 µm).

Tetractines II ( Figure 5 I, right): regular or subregular. The basal actines are conical and undulating with blunt tips. The apical actines are conical, thicker and longer than the apical actines of tetractine I, with sharp tips and a conspicuous constriction at the base (basal: 100–165–200 µm / 15–21–28 µm; apical: 280–476–725 µm / 18–39– 55 µm).

Remarks. No species of Pericharax had previously been reported with tripods although there are two species of Leucetta with this kind of spicule: L. insignis Row & Hôzawa, 1931 and L. prolifera ( Carter, 1878) . However, the tripods of these two species are much shorter and thinner than those of P. vallii sp. nov. ( L. insignis : 200-260/ 30-60 µm; L. prolifera : 263-578/32-63 µm; P. vallii : 611-798/237-257 µm). In addition L. prolifera has tetrapods not seen in P. vallii sp. nov. The new species is also distinguished from all other Pericharax and Leucetta species by the presence of a palisade of apical actines in the atrial skeleton.

Figures

FIGURE 5. Pericharax vallii sp. nov. (WAM Z 45632, holotype). (A) Preserved specimen. (B) Cross-section of specimen WAM Z 40489 = UFRJPOR 7741 showing the cortex (ctx) and atrium (at) with canals surrounded by a palisade of apical actines. (C) Tangential section of the cortical skeleton. (D) Cross-section showing cortex (ctx), subcortical lacunae (sl) and canals (ch). (E) Detail of a hispid canal (ch). (F) Tangential section of the atrial skeleton showing exhalant canals (ex). White arrowheads point to apical actines. (G) Tripod. (H) Triactine. (I) Tetractines: tetractine I (left), tetractine II (right).