Clathria (Microciona) aquaradiata n. sp.

urn:lsid:zoobank.org:act: CF6F7864-95E8-465F-BF20-6E10BAD26FF6

Figure 11

Diagnosis. Papillae terminating in oscula. Subsurface aqueous canals radiate from oscula.

Etymology Species name refers to the subsurface radiating aquiferous canals terminating at oscula.

Material Examined Holotype RBCM 024-00008 - 004, Stn NM 407, Defence Isl., Howe Sd., BC, 49° 34.511’ N / 123° 16.425’ W, coll. N. McDaniel, 14 Dec 2019, 15 m depth, 1 specimen . Paratypes RBCM 018-00304 - 001, Stn NM 201, Piper Pt, Sechelt Inlet , BC, 49° 32.755’ N / 123° 47.537’ W, coll. N. McDaniel, 16 Feb 2008, 20 m depth, 1 specimen; RBCM 018-00142 - 001, Stn NM 235, Piper Pt, Sechelt Inlet , BC, 49° 32.755’ N / 123° 47.537’ W, coll. N. McDaniel, 11 May 2011, 13 m depth, one specimen; RBCM 018-00146 - 003, Stn NM 261, Defence Isl., Howe Sd , BC, 49° 34.544’ N / 123° 16.632’ W, coll. N. McDaniel, 5 Jul 2011, 18 m depth, 1 specimen; RBCM 018-00130 - 002, Stn NM 312, Anvil Isl., Howe Sd ., BC, 49° 31.99’3 N / 123° 17.468’ W, coll. N. McDaniel, 17 Jun 2015, 20 m depth, 1 specimen; RBCM 018-00131 - 001, Stn NM 315, Anvil Isl., Howe Sd ., BC, 49° 31.993’ N / 123° 17.468’ W, coll. N. McDaniel, 17 Jun 2015, 20 m depth, 1 specimen; RBCM 018-00137 - 002, Stn NM 323, Sakinaw Rock, Sechelt Inlet , BC, 49° 34.009’ N / 123° 48.150’ W, coll. N. McDaniel, 24 Feb 2016, 25 m depth, 1 specimen; RBCM 024-00010 - 004, Stn NM 396, Defence Isl, Howe Sd ., BC, 49° 34.511’ N / 123° 16.425’ W, coll. N. McDaniel, 24 Sept 2019, 15 m depth, 1 specimen . Other Material Stn NM 333, Sakinaw Rock, Sechelt Inlet, BC, 49° 34.07’ N / 123° 48.238’ W, coll. N. McDaniel, 18 Mar 2016, 20 m depth, 1 non-voucher specimen .

Description

External (Figure 11A) Holotype RBCM 024-00008-004. (Figure 11B representative whole sponge) Thin encrusting, spreading indefinitely, 1 mm thick. Surface microhispid. Widely spaced papillae, many with oscula 1 mm diameter. Ostia numerous over the entire surface; not always visible in live specimens. Radiating subdermal canals may be visible originating from oscula. Colour orange, yellow-orange or yellow. Consistency fairly easily torn.

Skeleton (Figure 11C) Hymedesmioid. Ectosome styles/subtylostyles tangential and randomly disposed. Choanosome large and small acanthostyles with heads on the basal spongin plate and rising vertically. Large acanthostyles protrude from the surface from 100–300 µm. Abundant palmate isochelas (holotype; variable in other specimens (see Table 8)) and uncommon recurved toxas within the choanosome; less commonly in the ectosome.

Spicules (Figures 11D, E, F, G and H) Styles to subtylostyles, small and large acanthostyles, palmate isochelas, toxas. Styles to subtylostyles (Figure 11D) straight, head swelling elliptical, sharp apices, dimension range 88–494 x 3.1–15.6 µm. Large acanthostyles (Figure 11E) slightly curved or straight, highly variable length, nubby spines only on head, long, sharp apices, dimension range 177–735 x 7.8–33.8 µm. Small acanthostyles (Figure 11F) straight, spined except apex (¼ from apex usual), heads round or square, sharp apices, dimension range 63–546 x 5.2–28.6 µm. Palmate isochelas (Figure 11G) shaft nearly straight, fused alae on the back side extend slightly beyond the front alae; front alae divide the chela into thirds, dimension range 11.7–26.0 µm. Toxas (Figure 11H) recurved variably, thin (2–3 µm), dimension range 55–229 µm long. Microscleres may be rare or apparently absent in some specimens. Table 10 lists spicule dimensions of specimens examined.

n = 50 or as indicated

Distribution Howe Sd and Sechelt Inlet, BC; 13–25 m depth.

Ecology Forms thin encrustations up to 10 cm in diameter on bedrock and overgrowing barnacles.

Remarks A common Clathria (Microciona) species in Southwest BC coastal waters.

Clathria (Microciona) is a cosmopolitan subgenus found in all oceans except the Arctic Ocean; one species was reported from the Bering Sea ( C. (M.) primitiva Koltun, 1955). Described species for the North Pacific include 7 species: one in the Northwest Pacific and six in the Northeast Pacific (Table 11).

In addition to the species listed in Table 11 the late Dr. Bill Austin listed range extensions for four species on his website Mareco.org: Clathria (Microciona) brepha to Jervis Inlet, BC, Clathria (Microciona) microjoanna to Washington State, USA, Clathria (Microciona) primitiva to Knight Inlet, BC, and Clathria (Microciona) spongigartina to Anthony Island, BC. Clathria (M.) brepha, C. (M.) primitiva and C. (M.) spongigartina are in the Austin sponge collections at RBCM:

C. (M.) brepha RBCM 018-00289-001

C. (M.) primitiva RBCM 018-00380-001

C. (M.) spongigartina RBCM 018-00312-003

Referring to Table 11, C. (M.) brepha, C. (M.) rumsena, C. (M.) spongigartina and C. (M.) sp. Hartman lack toxas, C. (M.) microjoanna, C. (M.) parthena, C. (M.) rumsena, C. (M.) spinatoxa and C. (M.) spongigartina have only one size class of acanthostyles. It is unclear on what basis C. (M.) pennata belongs to the subgenus as it lacks acanthostyles. Clathria (M.) primitiva Koltun, 1955 lacks isochelas and toxas based on the author’s description.