Clathria (Clathria) Schmidt, 1862

Bertolino, Marco, Costa, Gabriele, Reboa, Anna, Bavestrello, Giorgio, Pansini, Maurizio, Betti, Federico, Bo, Marzia & Daneri, Giovanni, 2019, The sponge fauna of the Seno Magdalena and Puyuhuapi Fjord (Chile), with a description of two new species, Zootaxa 4623 (2), pp. 306-320 : 318

Subgenus Clathria (Clathria) Schmidt, 1862

Clathria (Clathria) microxa Desqueyroux, 1972

( Fig. 6 )

Material. CILE 80, Seno Magdalena E (44.613885°S 72.941490°W), Puerto Cisnes (Chile), depth 25 m, on a vertical cliff, 2014 .

Description. Small (4 cm 2), massive sponge, 2 cm thick. Surface rugose, with slightly elevated, round oscules. The colour in life is dark purple ( Fig. 6A ). The sponge is soft and fragile.

Skeleton. The skeleton shows a typical plumo-reticulate arrangement present in Clathria (Clathria) .

Spicules. Megascleres: choanosomal principal styles, straight or slightly curved, with smooth shaft and microspinate heads, 326.4 (376.9) 520.2 x 16.4 (18.6) 20.5 µm ( Fig. 6B ); subectosomal auxiliary subtylostyles, straight or sinuous, spines restricted to the heads, 244.8 (402.9) 561 x 5.7 (9) 12.3 µm ( Fig. 6C ); echinating acanthostyles, straight, with spines along the entire spicule length, spines of the head may be bifid or trifid ( Fig. 6D ), 119 (144.5) 170 x 8.5 µm. Microscleres: toxas variously curved in the middle, or even straight ( Fig. 6E ), 82 (216.9) 369 µm; straight microxeas, often showing a biconical shape ( Fig. 6F ), 36.9 (42) 45.1 x 2.6 (2.7) 5.2 µm.

Ecology. This species was first recorded at 50–90 m depth ( Desqueyroux, 1972) and then found as epibiotic on mollusc shells ( Zygochlamys patagonica and Fusitriton magellanicus ) between 92 and 100 m depth ( Schejter et al., 2006, 2011). Our specimen lived on a vertical cliff at 25 m depth.

Distribution. Corcovado Gulf ( Chile) ( Desqueyroux, 1972), Argentina ( Schejter et al., 2006, 2011) and Puyuhuapi Fjord (Queulat Fjord, Chilean Patagonia).

Remarks. Desqueyroux (1972) observed a single type of angulate toxas in the holotype. Also, Schejter et al. (2006) recorded a single type of long, and multiply bent toxa. Since we observed toxas of different shapes, even if they cannot be divided into categories, the spicule variability of the species increases. Furthermore, due to more detailed SEM photos, we could detect the microspination of the heads of styles and subtylostyles.

Figures

FIGURE 6. Clathria (Clathria) microxa: (A) live sample; (B) Principal styles; (C) Subectosomal auxiliary subtylostyles; (D) Echinating acantostyles; (E) Toxas; (F) Straight microxeas.