Suberites concinnus Lambe 1895

Suberites concinnus Lambe, 1895

Figs. 20, 21

Suberites montiniger: Koltun 1966; Austin 1985; Austin & Ott 1987 Non: Suberites montiniger Carter, 1880

Material examined. Syntype: CNM 1900–2822 (previously 2553), Bering I., Commander Islands, USSR, (55º 0.1′N, 166º 16.4′W), found on beach, coll. L. Stejneger, 1882–1883.

Other material: RBCM 976-1038-6, Hatie I., Portland Canal, BC, (55º 17'N, 129º 59'W), Mar. 23, 1976, coll. P. Lambert; RBCM 974-224-2, Winter Inlet, BC, (approx. 54º 49'N, 130º 26'W), no depth, Jun. 13, 1974, 3 specimens; RBCM 974-552-1, Wales I., BC, (approx. 54º 42'N, 130º 28'W), no depth, Jul. 29, 1974; RBCM 974- 390-5, Grace Point, BC, (approx 54º 38'N, 130º 26'W), no depth, 1974, coll. P. Lambert; RBCM 974-230, Brundage Inlet, Dundas I., BC, (approx. 54º 37'N, 130º 50'W), no depth, Jun. 19, 1974; RBCM 974-563-2, Coghlan Arch near Banks I., BC, (approx. 54º 27'N, 130º 41'W), no depth, 1974; RBCM 976-104-21, Langara I., BC, (approx. 54º N, 133º W), Apr. 30, 1976; KML 1060, KML sta. 174/76., Houston Stewart Channel, BC, (52º 09.5'N – 131º 05.6'W), 24 m depth, Aug. 31, 1976, coll. W.C. Austin; KML 1058, KML 602/77, Houston Stewart Channel, BC, (approx. 52º 9'N, 131º 5'W), 1977, coll., W.C. Austin; CMN H31, Kitasu Bay, BC, (approx. 51° 27'N, 127º 44'W), no depth, Jul. 20, 1964, coll. E.L. Bousfield; KML 1057, PEI 169, Dimsey Point, Rivers Inlet, BC, (51º 27'N, 127º 44'W), 5 m depth, no date, coll. & photo N. McDaniel; KML 1056, KML sta. 270/70, Pine I., BC, (50º 58.5'N, 127º 43.7'W), 20 m depth, Sept. 15, 1970, coll. W.C. Austin; RBCM 977-158-5, Boxer Pt., Nigei I., BC, (50º 50'N, 127º 39'W), 25 m depth, no date, coll. unknown.; RBCM 977-139-08, Minstrel I., BC, (approx. 50º 37'N, 126º 17'W), 25 m depth, Jul. 8, 1977; KML 1059, PEI 83, Steep I. W of Gowland Harbour,, BC, (50º 4.8'N, 123º 15.3'W), 20 m depth, Mar. 6, 1977, coll. & photo, N. McDaniel; KML 124/76, East of Effingham I., BC, (48º 52.7'N, 125º 17.2'W), 24, 50 m depth, Jul. 26, 1976, coll. W.C. Austin; KML 1061, KML sta. 124/76, E of Effingham I., BC, (48º 52.7'N, 131º 05.6'W), 24–50 m depth, no date, coll. W.C. Austin.

Field images without vouchers: Gordon Rock, E of Malcolm Island, BC, (approx. 50º 35'N, 126º 53'W), photo N. McDaniel; Plumper Rock, E. of Malcolm I., Weynton Pass, 4 km NW of NW Point on Hanson I., BC, (approx. 50º 35'N, 126º 49'W), photo N. McDaniel; Discovery Passage, BC, (approx. 50ºN, 125º 11'W), 4 photos N. McDaniel; Race Rocks, BC, (approx. 48º 18'N, 123º 32'W), photo N. McDaniel; Active Pass, BC, (approx. 48º 52'N, 123º 18'W), photo N. McDaniel.

Comparative material: Suberites montiniger, NOAA 27218, Stefansson Sd., Beaufort Sea, (70º 19'N, 147º 35'W), 6 m depth, no date, coll. unknown.

Description. Macroscopic features. (Fig. 20 A–E). Irregularly globular, typically 11 cm long by 7 cm wide by 5 cm thick. Oscula range from one to many; in life may be on short chimneys. Soft and porous alive; contracts 70% to moderately hard to soft rubbery texture when preserved in alcohol. In life surface may be white to orange covering a brownish orange to white interior.

Microscopic features. (Fig. 20 F). Surface megascleres in tufts oriented vertically. Choanosomal megascleres randomly oriented. Together these form layer about 300 µm thick.

Spicules (Fig. 21 A–I). Megascleres of KML 1056 examined in detail; exclusively styles, most straight, some with slight bend. No difference in spicule type or size between the ectosome and choanosome. Megascleres of nine additional specimens from range of BC localities examined for presence of styles and incipient subtylostyles summarized in Tables 11 and 12, and Figs. 21 E–G). SEMs from a specimen of Suberites montiniger from the Beaufort Sea included for comparison (NOAA, cat. 27218) (Figs. 21 H–I).

KML 1056

Location Spicule Type Fig. Length Width

Ectosome Style 21A–B 190–(224)–260 5–(5.0)–6 Choanosome Style 21C–D 200–(229)–250 5–(5.2)–6 Microscleres absent.

Remarks. We searched for records of Suberites from the northern hemisphere with styles or subtylostyles but not tylostyles. Three species are recorded in the Porifera database by van Soest et al. (2012): Suberites concinnus Lambe, 1895, Suberites montiniger Carter, 1880, and Suberites montalbidus Carter, 1880. Suberites montalbidus invariably has centrotylote microxea or microstrongyles (Carter 1880; Vosmaer 1882; Fristedt 1885, 1887; Lambe 1895) and so can be excluded from further consideration.

Lambe’s specimens of S. concinnus ranged from the Gulf of Alaska to Bering I. at the west end of the Aleutians. Burton (1935) recorded a typical specimen from Saghalien Bay, Kol, Sea of Okhosk from 3– 8 m.

Lambe (1895) described and figured the smooth styles in his specimens. They ranged from 229–301 x 5 µm. The maximum size is 40 µm larger than that found in the material we examined. However, we did not search for the largest spicule but rather measured a random sample of 20 spicules.

Koltun (1966) placed S. concinnus in synonymy with Suberites montiniger (Carter 1880). His rationale was not explicit. He stated that, typically, the megasclere size range in S. montiniger is 200–270 x 3–6 µm, comparable to the size range we find in S. concinnus. But Koltun also observed that a few specimens had megascleres ranging from 330–600 x 10 µm—much longer than we find in specimens in British Columbia or southern Alaska. The megascleres in our specimen of S. montiniger from the Beaufort Sea are significantly longer (Table 12, mean 318 Μm) than in our specimens of S. concinnus (means 212–237 Μm). The megascleres in Koltun’s material were characterized as subtylostyles not styles. One might surmise that Koltun did not consider the difference between styles and subtylostyles as significant. Our examination of spicules in nine additional specimens (Table 11) revealed one example with significant numbers of incipient subtylostyles. But 50% of the spicules were styles. It was collected in the same region as many of the other specimens with a low % of subtylostyles. On the other hand, 99% of the spicules observed were subtylostyles and 1% were styles on examination of a specimen we consider to be Suberites montiniger sensu strictu from the Beaufort Sea. The subtylostyles in this specimen of S. montiniger have a significantly longer swollen head (Fig. 21 H, I) than the incipient subtylostyles of one specimen of S. concinnus (Fig. 21 F, G).

Except for Koltun (1966) who merged the two species, neither Carter (1880), Vosmaer (1882) nor Hentschel (1916) mentioned the relative proportion of styles to subtylostyles among megascleres in their descriptions of S. montiniger.

Suberites montiniger and S. cocinnus may differ in biogeographic zones. Records of S. montiniger are from 70–80 degrees N in the Barents Sea and Greenland Sea (Carter 1880; Vosmaer 1882; Hentschel 1916, 1929; Swartschewsky 1906) and from the Beaufort Sea (this paper). Records of S. concinnus are from 50–60 degrees N in the Sea of Okhotsk, Bering Sea, Gulf of Alaska and British Columbia (Lambe 1895, Burton 1935, this paper). One exception is an identification of S. montiniger from 48 degrees N in the northern part of the Sea of Japan by Burton (1935). We suggest that this record needs verification.

Topsent (1915), Hentschel (1916) and Koltun (1966) note that a specimen referred to S. montiniger by Lambe (1895) is not this species as it has subtylostyles averaging 16 Μm in diameter compared to 5–6 Μm for S. montiniger. We agree but will not attempt to assign it to another species.

Conclusions. In our opinion the difference in prevalence of styles versus subtylostyles and differences in spicule mean size and range, coupled with largely different zoogeographic zones (Arctic vs. cold temperate and boreal) supports maintaining S. concinnus as a separate species from S. montiniger. The one specimen among eleven which has a significant number of (incipient) subtylostyles (RBCM 974-563-2, Table 11) may be an anomaly or possibly a hybrid. Also, these subtylostyles are different from those in our specimen of S. montiniger: the tyle is shorter and with a more angular apex. Finally, the size range and mean of spicules in RBCM 974-563-2 fit the other S. concinnus specimens, not the S. montiniger specimen (NOAA 27218) (Table 12).

Bathymetric range. 3 to 118 m depth.

Geographic distribution. Sea of Okhotsk (Russia) east to the Gulf of Alaska (USA) and south to southern BC (Canada).

Ecology. This species is restricted to current swept rocks.