Eurypon tylospinosum, Aguilar-Camacho & Carballo, 2013

Eurypon tylospinosum sp. nov.

( Figures 14B View Figure 14 , 17 View Figure 17 , 18 View Figure 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 View Figure 14 ).

Skeleton

Choanosomal subtylostyles with a pronounced head or modified to style: 200–575 × 7.5–15 µm ( Figures 17A View Figure 17 , 18A View Figure 18 ). 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 View Figure 17 , 18B View Figure 18 ). Straight or curved subectosomal styles / anisoxeas: 330–460 × 1.75–2.5 µm ( Figures 17D View Figure 17 , 18C View Figure 18 ) ( 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 View Figure 18 ).

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.