Antho (Acarnia) flavoaurantiaca, 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 : 175-177

Antho (Acarnia) flavoaurantiaca n. sp.

urn:lsid:zoobank.org:act:C8ECF029-6BA3-4725-8EBB-F584002980AD

Figure 10

Diagnosis. Thin encrusting orange sponge, spreading irregularly, spicules include subtylostyles, acanthostyles and palmate isochelas; lacks toxas.

Etymology Species name references the yellowish orange colour of specimens examined.

Material Examined Holotype RBCM 018-00130 - 003 , Stn NM 313 , Anvil Isl, Howe Sd, BC, 49° 31.113’ N / 123° 17.468’ W, coll. N. McDaniel, 17 June 2015, 20 m depth, 1 specimen . Paratypes RBCM 018-00139 - 002 , Stn NM 328 , Sakinaw Rock, Sechelt Inlet , BC, 49° 33.956’ N / 123° 48.254’W, coll. N. McDaniel, 25 Feb 2016, 20 m, 1 specimen ; RBCM 024-00011 - 001 , Stn NM 367 , Prominent Pt., Knight Inlet , BC, 50° 40.063’ N / 126° 0.609’ W, coll. N. McDaniel, 9 May 2018, 10 m depth, 1 specimen . Other Material Stn. NM 320 , Sakinaw Rock, Sechelt Inlet, BC, 49 33.997° N / 123 48.150° W, coll. N. McDaniel, 5 January 2016, 25 m depth, 1 non-voucher specimen .

Description

External ( Figure 10A ) Holotype RBCM 018-00130 - 003 . Thin encrusting 0.5–1 mm. Surface smooth, nubbly. Colour orange brown. Consistency easily torn. Growing on a boulder. The sponge covered an area approximately 10 to 15 cm across as shown in Figure 10A , including partly covering the valves of the three small barnacles.

Skeleton ( Figure 10B ) Ectosome composed of a dense layer of tangentially oriented subtylostyles apparently without order. Choanosome composed of basal plate with acanthostyles head end embedded in the plate and a dense layer of acanthostrongyles adjacent to the plate and randomly arranged.

Spicules ( Figures 10C, D, E, F and G ) Stylotornotes, large acanthostyles, small acanthostyles, acanthostrongyles and palmate isochelas. Stylotornotes ( Figure 10C ) straight with long apices; heads only slightly swollen. The tips of heads may be microspined, dimension range 108–250 x 3.9–8.6 µm. Large acanthostyles ( Figure 10D ) slightly curved to long apices, spine up to one quarter length, dimension range 80–935 x 7.8–31.2 µm. Small acanthostyles ( Figure 10E ) mostly straight, two thirds to entirely spined, dimension range 75–224 x 7.8–20.8 µm. Acanthostrongyles ( Figure 10F ) most slightly curved, inequiended, entirely spined, dimension range 57–140 x 7.8–26/0 µm. Palmate isochelas ( Figure 10G ) small, moderately curved, with a slightly raised central dorsal ridge extending to within ¼ of the two tips, palmate alae equal and 1/3 chord length, lateral alae narrow, same length as palmate alae, dimension range 8.2–31.2 µm. Table 9 lists spicule dimensions of specimens examined.

Distribution Howe Sound, Sechelt and Knight Inlets, BC; 10–20 m depth.

Ecology Forms encrustations up to 20 cm in diameter on bedrock and often overgrowing Balanus spp. shells.

Remarks The maximum length of large acanthostyles varies considerably amongst the specimens collected, but is not considered a sufficient difference to warrant separate species. Three Antho (Acarnia) species are located in the North Pacific: A. (A.) bakusi Sim & Lee, 1998 , A. (A.) illgi ( Bakus, 1966) (as Plocamilla ) and A. (A.) spinulosa ( Tanita, 1968) (as Lissodendoryx ). Antho (A.) bakusi Sim & Lee, 1998 was described from Korea, 25 m depth. Its habitus and colour are similar to A. (A.) flavoaurantiaca n. sp. but the ectosomal spicules are oriented perpendicularly and the sponge has a cortical layer between the ectosome and choanosome. Toxas are present but uncommon. Antho (A.) illgi ( Bakus, 1966) was described from Puget Sound, Washington State, a number of specimens from low tide to 31 m depth. Habitus and colour were similar to A. (A.) flavoaurantiaca n. sp. but the choanosome principle megascleres are styles not acanthostyles and the sponge complement includes toxas. A. (A.) spinulosa ( Tanita, 1968) was described from Japan; no depth or colour in life were provided. Habitus was irregularly massive with a hispid surface, not encrusting. Tanita’s sponge lacks acanthostyles, has rare arcuate isochelas and toxas. None of the three previously described North Pacific Antho (Acarnia) is conspecific with A. (A.) flavoaurantiaca n. sp. The BC species is a range extension into the Northeast Pacific.

Figures

FIGURE 10. Antho (Acarnia) flavoaurantiaca n. sp. Holotype RBCM 018-00130-003 (A) In-situ. (B) Skeleton cross section. (C) Stylotornotes. (D) Large ancanthostyles. (E) Small acanthostyle. (F) Acanthostrongyle. (G) Palmate isochelas.