Eurypon tylospinosum, Aguilar-Camacho & Carballo, 2013

Aguilar-Camacho, Jose Maria & Carballo, Jose Luis, 2013, Raspailiidae (Porifera: Demospongiae: Axinellida) from the Mexican Pacific Ocean with the description of seven new species, Journal of Natural History (J. Nat. Hist.) 47 (25 - 28), pp. 1663-1706 : 1687-1690

Eurypon tylospinosum sp. nov.

( Figures 14B , 17 , 18 )

Material examined

Holotype: MCNM 1.01 / 659, 27 / 11 / 2002, Cabo Haro, ( Guaymas , Sonora) 15 m (27 ◦ 52 ′ 5 ′′ N, 110 ◦ 57 ′ 1 ′′ W) . Paratype: 769-LEB-ICML-UNAM, 27 / 11 / 2002, Cabo Haro, ( Guaymas , Sonora), 15 m (27 ◦ 52 ′ 5 ′′ N, 110 ◦ 57 ′ 1 ′′ W).

Description

Encrusting sponge, size 2–5 cm length × 1–2 cm width and 3–5 mm thick. Oscules and ostia not visible. Surface smooth. Consistency flexible and difficult to tear. Colour in life red, pale in preservation ( Figure 14B ).

Skeleton

Choanosomal subtylostyles with a pronounced head or modified to style: 200–575 × 7.5–15 µm ( Figures 17A , 18A ). Acanthostyles with swollen head with prominent spines. These spines are arranged as a crown around the head: 70–200 × 2.5–7.5 µm ( Figures 17B, C , 18B ). Straight or curved subectosomal styles / anisoxeas: 330–460 × 1.75–2.5 µm ( Figures 17D , 18C ) ( Table 9). The ectosomal skeleton is absent. The choanosomal skeleton has a hymedesmoid structure. Main subtylostyles and acanthostyles are embedded in a spongin layer (10–25 µm thick). The styles / anisoxeas are dispersed in trichodragmas in the subectosomal region ( Figure 18D ).

Remarks

Eurypon tylospinosum sp. nov. is a subtidal species distributed from the Gulf of California. It is characterized by having acanthostyles with swollen head and with prominent spines, which are arranged as a crown around the head. The only species described worldwide that have these features are E. simplex ( Bowerbank 1874) and E. coronula ( Bowerbank 1874) ( Table 12). Eurypon simplex ( Bowerbank 1874) is a yellow encrusting sponge described from the Shetland Islands. It has tylostyles (2116 × 27.1 µm) and acanthostyles (105.8–218.9 × 8.4 µm). The tylostyles are shorter in E. tylospinosum sp. nov. than in E. simplex . Besides, E. tylospinosum sp. nov. has subectosomal styles which are lacking in E. simplex . Eurypon coronula ( Bowerbank 1874) is a grey encrusting sponge recorded from the Shetland Islands. It has tylostyles (635–1411 µm) and acanthostyles (254 µm). The tylostyles are longer in E. coronula than in E. tylospinosum sp. nov. The remaining species assigned to the genus Eurypon have spicules in a different category or length than E. tylospinosum sp. nov. ( Table 12).

Etymology

Named tylospinosum by the swollen and spiny head of the acanthostyles.

Figures

Figure 14. Photographs of preserved sponges from this study. (A) Eurypon patriciae sp. nov. (B) Eurypon tylospinosum sp. nov. (C) Eurypon diversicolor sp. nov. (D) Eurypon brunus sp. nov. Scale bars: 1 cm (A, B, D), 2 cm (C).

Figure 17. Eurypon tylospinosum sp. nov. Scanning electron microscopy images of spicules. (A) Choanosomal tylostyles; (B) acanthostyle with swollen head I; (C) acanthostyle with swollen head II; (D) subectosomal style. Scale bars: 50 µm (A), 10 µm (B), 20 µm (C), 100 µm (D).

Figure 18. Drawings of Eurypon tylospinosum sp. nov. (A) Choanosomal tylostyles/styles; (B) acanthostyles recurved by prominent spines (two categories); (C) subectosomal styless/anisoxeas; (D) choanosomal skeleton (hymedesmoid). Scale bars: 40 µm (A–C), 75 µm (D).