Leucetta foliata, 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 : 322-324

Leucetta foliata sp. nov.

Etymology. From the Latin adjective foliatum (=laminated, leafy), referring to the peculiar foliaceous form of the body of this species.

Diagnosis. Leucetta with a foliaceous form and a large atrium showing conspicuous hispid exhalant canals. The surface is smooth and the skeleton is composed of two categories of triactines and three of tetractines.

Type material. Holotype, WAM Z40351; 30º33.37’S, 115º04.08’E, Margaria Reef , Cervantes, Western Australia ; station: JWAM18/T3; depth: 7 meters; collectors: Fromont, J., Whisson, C. S. & Moore, G. I.; date: 08/ March/2006. Fragment from Holotype deposited under UFRJPOR 7149. Paratype, WAM Z45623; 34º03’00”S, 122º38’00”E Middle Island , Recherche Archipelago, Western Australia ; station: MIDE 1V; depth: 15 meters. Fragment from Paratype deposited under UFRJPOR 7108.

Type Locality. Cervantes , Western Australia, Australia.

Description. Sponge beige in ethanol with a foliaceous form (13 cm x 5.5 cm) and a large apical osculum (12 cm x 2 cm) ( Figure 2 A). The surface is smooth but rough to the touch, and inhalant canals are conspicuous. The atrial cavity is very large, smooth, and centrally located. It has conspicuous exhalant canals and the aquiferous system is leuconoid.

The skeleton, composed of triactines and tetractines, is disorganized, which is typical for the genus. The cortical skeleton is composed of large tetractines tangentially disposed together with small triactines that form a reticulation ( Figure 2 B). Large triactines and small tetractines I can also be found in the cortex, but are much less common. No subcortical lacunae are present. The choanosome is composed of small triactines and small tetractines I ( Figure 2 C), the latter found mainly surrounding the inhalant canals where they project the apical actines inwards ( Figure 2 D). Small tetractines II are found in the exhalant canals ( Figures 2 E, 2F). The atrial skeleton is principally composed of large and small triactines ( Figure 2 E). Large tetractines are rarely found in the atrial skeleton.

Spicules. ( Table 2). Large tetractines ( Figure 2 G): regular or subregular (i.e. spicules whose actines have different lengths and/ or different angles). The basal actines are conical with blunt tips (basal: 184–310–486 µm / 15–57–95 µm).

Large triactines ( Figure 2 H): regular or subregular. Actines are conical with blunt tips (197–332–410 µm / 27– 57–76 µm).

Small triactines ( Figure 2 I): regular (equiangular and equiradiate), although sagittal spicules form the cortical reticulation. Actines are conical with blunt or sharp tips (89–130–162 µm / 11–18–21 µm).

Small tetractines I ( Figure 2 J, left): regular. Basal actines are conical with blunt tips. Apical actines are conical, thin and short, straight or slightly curved at the end, with sharp tips (basal: 81–130–154 µm / 11–16–19 µm; apical: 27–40–78 µm / 3–6–8 µm).

Length (µm) Width (µm)

Spicule Actine Min Mean sd Max Min Mean sd Max n

Large triactines

WAM Z40351 (H) 197.1 265.4 60.6 405.0 27.0 42.8 12.6 75.6 20

WAM Z45623 (P) 200.0 331.5 51.7 410.0 40.0 57.3 9.0 70.0 20

Small triactines

WAM Z40351 (H) 89.1 128.3 19.0 162.0 10.8 15.5 2.7 18.9 20

WAM Z45623 (P) 100.0 129.6 14.5 160.0 13.7 17.8 2.3 21.2 20

Large tetractines Basal

WAM Z40351 (H) 183.6 301.7 80.4 486.0 32.4 50.8 14.5 86.4 20

WAM Z45623 (P) 235.0 309.5 57.7 475.0 15.0 56.7 22.6 95.0 20

Small tetractines I Basal

WAM Z40351 (H) 108.0 129.6 10.3 153.9 10.8 14.3 1.6 16.2 20

WAM Z45623 (P) 81.0 116.5 13.9 148.5 13.5 15.7 1.6 18.9 20

Apical

WAM Z40351 (H) 29.7 40.4 11.5 78.3 2.7 6.0 1.7 8.1 20

WAM Z45623 (P) 27.0 39.4 6.9 51.3 4.0 5.8 1.1 8.1 20

Small tetractines II Basal

WAM Z40351 (H) 48.6 73.6 12.5 97.2 8.1 10.1 1.4 13.5 20

WAM Z45623 (P) 82.5 128.6 21.3 155.0 12.5 16.8 1.7 20.0 20

Apical

WAM Z40351 (H) 105.3 147.0 29.5 216.0 8.1 11.3 1.3 13.5 20

WAM Z45623 (P) 105.0 156.8 37.0 237.5 10.0 13.3 2.0 17.5 20 Small tetractines II ( Figure 2 J, right): regular. Basal actines are slightly conical and undulated, with blunt tips. Apical actines are slightly conical, thick, long, slightly curved at the end, and sharp (basal: 49–129–155 µm / 8–17– 20 µm; apical: 105–157–238 µm / 8–13–18 µm).

Remarks. There are two species of Leucetta that, as also seen in L. foliata sp. nov., have more than one category of triactine and tetractine: L. floridana ( Haeckel, 1872) , known from the Caribbean and the Northeast of Brazil, and L. potiguar Lanna et al., 2009 , endemic to the Northeast coast of Brazil ( Lanna et al. 2009). Leucetta foliata sp. nov. contains three different types of tetractines, while L. floridana and L. potiguar have only two. In addition, L. foliata sp. nov. has large triactines and tetractines (although rare) in its atrial skeleton, which are not observed in L. floridana or L. potiguar . Finally, L. foliata sp. nov. has a distinctive external foliose morphology, not previously seen in the genus.

Figures

FIGURE 2. Leucetta foliata sp. nov. (WAM Z 40351, holotype). (A) Preserved specimen. (B) Tangential section of the cortical skeleton. (C) Cross-section showing cortex (ctx) and canals (ch). (D) Detail of hispid canal (ch). (E) Tangential section of the atrial skeleton showing exhalant canals (ex). (F) Detail of hispid exhalant canal (ex). (G) Large tetractine. (H) Large triactine. (I) Small triactine. (J) Small tetractines: small tetractine I (left), small tetractine II (right).