Eurypon microtuberculatum, Ott & Mcdaniel & Humphrey, 2024

Ott, B., Mcdaniel, N. & Humphrey, E., 2024, Fourteen new species of demosponges (Porifera) from three coastal fjords in southern British Columbia, Canada, Zootaxa 5463 (2), pp. 151-200 : 160

Eurypon microtuberculatum n. sp.

urn:lsid:zoobank.org:act:75FF17C9-9928-4C8B-BA99-331B41AAEE4B

Figure 4

Diagnosis. Very thin encrusting with tuberculate finely hispid surface.

Etymology The species name refers to the sponge surface texture.

Material Examined Holotype RBCM 018-00130 - 004 , Stn NM 314 , Anvil Isl, Howe Sd, BC, 49° 31.993’ N / 123° 17.468’ W, coll. N. McDaniel, 17 Jun 2015, 20 m depth, one specimen.

Description

External ( Figure 4A ) Holotype: RBCM 018-00130 - 004 . Thinly encrusting, 10 cm across by about 1 mm. Surface micro tuberculate, microhispid. Colour orange. Consistency: fairly easily torn.

Skeleton ( Figure 4B ) No specialized ectosome. Hymedesmioid choanosome composed of tylostyles and acanthostyles embedded in base and arising vertically. Tylostyles penetrate the surface. Acanthostyles form a dense palisade on the base, heads down. Subtylostyles form brushes around the large tylostyles above the acanthostyles and up to the surface but do not penetrate it.

Spicules (Holotype Figures 4C, D , and E). Tylostyles, subtylostyles and acanthostyles. Tylostyles ( Figure 4C ) with hemispherical or multilobed heads, straight or slightly curved, tapering uniformly to rounded apices, 431 (944) 1134 x 28.6 (47.7) 59.8 µm. Subtylostyles ( Figure 4D ) with eliptical heads, most straight, fusiform, apices mucronate, 147 (279) 578 x 7.8 (10.9) 13.0 µm. Acanthostyles ( Figure 4E ) head with large spines perpendicular to head surface or rounded head; shafts completely spined with spines normal to the shaft long axis, apices sharp, 57 (84) 130 x 20.8 (37.9) 46.8 µm (head width).

Distribution Known only from the type location, Howe Sound, BC, 20 m depth.

Ecology Forms small encrustations on vertical or near-vertical bedrock faces.

Remarks Eurypon microtuberculatum n. sp. has a different skeletal architecture and spicules from the other two Eurypon species herein described. Eurypon duoacanthostyla has two sizes of acanthostyles; E. inuisitatiacanthostyla is tubular. Eurypon tylospinosum has similarly embedded megascleres in a basal spongin plate but near surface styles form trichodragmas rather than brushes. Similarly, E. patriciae has strongyloxeas and styles in small groups around large tylostyles and not forming brushes. Eurypon nigrum is similar to E. microtuberculatum n. sp. in skeletal architecture but lacks subtylostyles and is blue in life not orange; spicule sizes also vary from E. microtuberculatum .

Figures

FIGURE 4. Eurypon microtuberculatum n. sp. Holotype RBCM 018-00130-004. (A) In-situ. (B) Skeleton cross section. (C) Tylostyles. (D) Subtylostyles. (E) Acanthostyle.