Clathria (Thalysias) oxeota

Zea, Sven, Rodríguez, Angélica & Martínez, Ana María, 2014, Taxonomy of Clathria (Thalysias) (Demospongiae: Poecilosclerida: Microcionidae) from the Colombian Caribbean, with description of three new species, Zootaxa 3835 (4), pp. 401-436 : 420-421

Clathria (Thalysias) oxeota (van Soest, 1984)

Figure 11 ; plate 2, figures C, D

Rhaphidophlus oxeotus van Soest, 1984: 120, fig. 48; Rozemeijer and Dulfer 1987, Appendix 1: 2; Rützler et al. 2009: 298 (records).

Clathria oxeotus ; Alcolado 2002: 64; Rützler et al. 2009: 298.

? Clathria cf. oxeotus ; Alcolado and Busutil 2012: 69.

Microciona sp. 5; Sánchez 1984: 55, Fig. 6.19.

Material examined. Holotype tissue slide, ZMA POR.4880, Curaçao, 300 m SE of Hilton Hotel, 33 m, on dead Meandrina coral, coll. R.W.M. van Soest, 17 Dec. 1980. Santa Marta: uncatalogued # PSM 328 spicule and tissue preparations of material from Rozemeijer & Dulfer (1987), Granate Bay, 1 m, overhanging rock, Jul.-Nov. 1986. Panama: uncatalogued fragments #PPA 14 (Casa Blanca, 6 m, 3 Mar. 2012), USNM 1204917 (PorTol project #P 12X 408, Airport, 12 m, 9 Aug. 2012), Bocas del Toro, Isla Colón, both on dead Agaricia tenuifolia coral, coll. S. Zea. The description below is based on Panamanian material.

Shape, color and consistency. Slightly thick (up to 1–2 mm) and fleshy encrustation. Surface smooth, with a transparent membrane elevated over subdermal canals and at oscules. Oscules about 1–5 mm in diameter. Ectosome is mottled whitish or yellowish, sometimes more intensively over canals; underlying tissue orange. Consistency soft.

Skeleton. The ectosome is a thin pinacoderm supported by brushes of small auxiliary subtylostyles. In the choanosome, single, large principal choanosomal styles are placed erect on the base, more or less evenly spaced, surrounded by erect accessory acathostyles. From each of these follow upwards one or more tracts of large auxiliary choanosomal subtylostyles, which diverge, ending in ectosomal brushes of the smaller category of subtylostyles, supporting the pinacoderm. Often there are tangential tracts of large and medium subtylostyles and oxeote toxa more or less parallel to the surface; tracts may be sometimes echinated by acanthostyles. Abundant small wing-shaped toxa and chelae dispersed throughtout the choanosome. Spicules (Table 1): (1) Choanosomal principal styles, somewhat curved, most with smooth heads but sometimes minutely spined, in a wide range of sizes, 215– 363.8 –700 µm by 10– 15.6 –30 µm. (2) Straight auxiliary subtylostyles with smooth to microspined heads; mid and large, choanosomal ones, 240– 427.4 –580 µm by 2.8– 6.2 –9.5 µm; small, ectosomal ones, 110– 143.7 –190 µm by 2.0– 2.7 –3.8 µm. (3) Echinating accessory acanthostyles, often with a distinct head, 53– 70.1 –90 µm by 2.5– 6.2 –8.0 µm. (4) Long, oxeote toxa, 620– 893.5 –1380 µm by 2.8– 5.1 9.8 µm. (5) Thin toxa in two shapes, large, accolada-type (straight with a central low curve), 50– 259.3 –450 µm and small, wing-shaped, 30– 56.1 –80 µm, and (6) Palmate isochelae, 12.5– 13.7 –15.3 µm.

Distribution and ecology. Cuba ( Alcolado 2002), Gulf of Mexico (Veracruz, see Rützler et al. 2009), Colombia (Santa Marta; also Sánchez 1984), Panama (Bocas del Toro). At Santa Marta, it inhabits dock pilings ( Sánchez 1984). At Bocas del Toro, Panama, and Curaçao, it is a reef species (6-33 m in depth).

Remarks. Although we did not collect material of this species in the Colombian Caribbean, we have included it in this report owing to previous records from Santa Marta. We were able to know directly the species from specimens observed and collected at Bocas del Toro, Panama, from which we made the description given above. These specimens have the same spicule complement of the holotype, excepting an additional category of small, wing-shaped toxa. Also, Panama specimens have generally larger spicules than the holotype, but this is a common feature of Southern Caribbean-Central American sponge populations (see Zea 1987; Valderrama & Zea 2013).

Although R.W.M. van Soest identified Rozemeijer and Dulfer’s (1987) Clathria (Thalysias) oxeota material from Santa Marta, we are somewhat doubtful of its identity. The tissue and spicule slides we were able to make from the small fragment made available to us shows smaller choanosomal styles (130–315 µm by 4.5–10.5 µm) than the holotype (228–456 µm) and the Panama specimen (215–700 µm); their heads are also slightly rugose and engrossed, in comparison to minutely spined in the holotype and mostly smooth in Panama. Also, the oxeote toxa are smaller (285–441 µm) in comparison to the holotype (530–995 µm) and the Panama specimen (620–1380). It also appears to be different from Microciona sp. 5 reported by Sánchez (1984) from Santa Marta, which we have decided belongs to C. oxeota from the drawing of its smooth choanosomal styles and its long, 700–1006 um oxeote toxa; however, Microciona sp. 5 chelae are smaller (8–9 um vs. 11–15 µm in other specimens). The identity of Clathria cf. oxeotus from Guadeloupe by Alcolado & Busutil (2012) remains to be confirmed.

Figures

FIGURE 11. Clathria (Thalysias) oxeota. SEM micrographs of spicules of a specimen from Bocas del Toro, Panama. (a) Choanosomal principal style, (b) choanosomal and subectosomal auxiliary subtylostyle, (c) ectosomal auxiliary subtylostyle, (d) echinating accessory acanthostyle, (e) oxeote toxa, (f) accolada toxa, (g) wing-shaped toxa, (h) palmate chelae.