Fig. 23
Suberites latus Lambe, 1893 b.
Lee et al. 2007: Key 16 Suberites montalbidus of Lambe, 1895. Ficulina suberea var. lata de Laubenfels, 1932.
Choanites suberea var. lata de Laubenfels, 1961.
Suberites domuncula (Olivi, 1792) ficus of Koltun 1966. Suberites ficus (Johnston, 1842) of Bakus & Green 1987.
Material examined. NOAA 0 27212, Boulder Patch, Stefansson Sd., Beaufort Sea, Alaska, (70 º 19.25 'N, 147 º 35.1 'W), 6 m depth, no date, 1 specimen; NOAA 0 22120, Chukchi Sea, South Alaska, (65 º 45.50 'N, 167 º 50.00'W), no depth, no date, 1 specimen; NOAA 0 18307, Bering Sea, Alaska, (65 º 16.0'N, 166 º 36.0'W), 12.7 m depth, no date; KML 1080, PBS sta. 63, 74, Kodiak, Alaska, (58 º 07.8'N, 150 º 51.0'W), 126 m depth, Aug. 31, 1963, coll. PBS, 1 specimen; KML 1082, PBS sta. 69, 11, S. of Rose Spit, Graham I., BC, (54 º 10.3 'N, 131 º 5.5 'W), 17 m depth, Jun. 1969, coll. PBS, 2 specimens; KML 1081, 16 km SW Archibald, BC, (approx. 54 º 06'N, 131 º 06'W), May 16, 1964, coll. PBS/JAT, 4 specimens; KML 1083, KML sta. 77 / 76, Skincuttle Inlet, BC, (52 º 19.8 'N, 131 º 12.4 'W), 150 m depth, Sept. 1, 1976, coll. W.C. Austin, 2 specimens; RBCM 780 - 267, Nakwakto Rapids, BC, (51 º 06'N, 127 º 30 'W), 1 specimen; KML 1084, KML sta. 63, 3, Malcolm I., BC, (50 º 37.7 'N, 127 º 01.8'W), 60 m depth, Jan. 12, 1963, coll. D.B. Quayle, 10 specimens; KML 1085, PBS sta. N- 7, Lawn Point, Haida Gwaii, BC, (approx. 53 º 25 'N, 131 º 55 'W), Beacon bearing 243 º, 28 m depth, Aug. 25, 1960, coll. D.B. Quayle, 1 specimen; KML 1090, KML sta. 70 / 75, Thiepval Channel, Barkley Sd., BC, (48 º 54.2 'N, 125 º 19.7 'W), 22 m depth, May 16, 1975, coll. W.C. Austin, 1 specimen; KML 1089, KML sta. 160 / 75, W. Satellite Passage, BC, (approx. 48 º 52 'N, 125 º 11 'W), no depth, 1975, coll. W.C. Austin, 1 specimen; KML 1087, KML sta. 105 / 76, N of Diana I., Barkley Sd., BC, (48 º 51.1 'N, 125 º 11.9 'W), 22–31 m depth, Jul. 8, 1976, coll. W.C. Austin, 1 specimen; KML 1102, KML sta. 67 / 87, Barkley Sd., BC, (approx. 48 o 51 'N, 125 o 14 'W), no depth, Jul. 19, 1987, coll. W.C. Austin, 1 specimen; KML 1088, KML sta. 261 / 72, off Barkley Sd., BC, (48 º 47 'N, 125 º 34 'W), 66 m depth, Aug. 15, 1976, coll. W.C. Austin, 1 specimen; KML 1091, KML sta. 63 / 68, Saltspring I., BC, (48 º 42.6 'N, 123 º 29.2 'W), 45 m depth, Aug. 25, 1963, coll. W.C. Austin, 1 specimen; KML 1086, KML sta. 201 / 76, W side Gilbert I., Barkley Sd., BC, (38 º 52.0'N, 125 º 19.8 ' W), 9 m depth, Nov. 24, 1971, coll. W.C. Austin, 1 specimen.
Field images, no vouchers: Welcome Passage, BC, (approx. 49 º 30 'N, 123 º 56 'W), 2 photos, N. McDaniel; Howe Sd., BC, (approx. 49 º 25 'N, 123 º 23 'W), 2 photos, N. McDaniel; Port Hardy, BC, (approx. 48 º 45 'N, 127 º 28 'W), photo, N. McDaniel.
Description. Macroscopic features. (Fig. 23 A, B, C). Body form ranges from thin crust on a snail shell to massive amorphous forms up to 10 cm long by 4 cm high by 6 cm wide. Individuals almost always contain one hermit crab (Pagurus stevensae Hart, 1971). Oscula sparse, flush with the surface, 2–3 mm in diameter in preserved samples. In life a firm rubbery consistency which is smooth to the touch. Brownish yellow to brownish red-orange in life.
Microscopic features. (Fig. 23 D). Ectosome with dense layer of relatively short tylostyles aligned normal to surface; pointed ends extend less than 0.1 mm beyond surface. Choanosome with irregularly distributed, relatively long tylostyles.
Spicules. Megascleres are two size classes of tylostyles, data given from KML 1085. Tylostyles 1 (shorter, Fig. 23 F) are restricted to ectosome. Tylostyles 2 (longer, Fig. 23 E) occur in both ectosome and choanosome. Both long and short tylostyles may be straight (Fig. 23 F) but are generally curved or sinuous (Fig. 23 E). The tyle is symmetrical or sometimes tilted to one side. It is occasionally lobed or expanded below the apex which is then styloid.
Tylostyles terminating at the cavity containing the hermit crab are strongylote rather than oxeote (Fig. 23 G). We also measured large tylostyle lengths of seven specimens from southern BC to 2500 km north off Kodiak (Alaska) (Table 13).
Microscleres are choanosomal centrotylote strongyles (Figs. 23 H–I) or oxeas; common, rare or apparently absent. In our material shaft is microspined; may be thick (5 µm) or thin (2.5 µm); tyle may occasionally be excentric. KML 1085 except for those with * which are from KML 1102.
Location Spicule Type Fig. Length Width Ectosome Tylostyle 1 23 F 103 –(130)– 153 5.0–(6.9)–10.0 Tylostyle 2 23 E 203 –(261)– 360 5.0–(8.4)– 12.5 Choanosome Tylostyle 2 23 E 218 –(300)– 345 5.0–(7.4)–10.0
Centrotylote strongyles 23 H, I 20 –(29)– 60 N= 12
18 –(23)– 33 N= 25 *
Remarks. Lambe (1895) commented that his rationale (Lambe 1893 b) for considering S. latus a distinct species was based on the absence of centrotylote strongyles. He subsequently found one or two of these spicules in some of the specimens he had named S. latus. He concluded that S. latus was, therefore, not distinct from S. suberea (Montagu, 1818). De Laubenfels (1932) pointed out that the tylostyles of Lambe’s specimens were on average longer (294–524 µm) than those of S. suberea (Montagu 1818) in British seas, and recommended that Ficulina suberea latus be retained as a subspecies.
Lambe (1893 b) stated that his specimens included two size classes of tylostyles; the larger ranging from 294–524 µm x 13 µm, and the smaller averaging 170 µm x 9 µm. The larger tylostyles are about 1 / 3 longer than the longest in specimens examined by us (Table 13). Lambe’s specimens came from localities off northern Vancouver I. and the adjacent mainland. Five of the specimens in Table 13 came from 20 to 200 km of the localities reported by Lambe.
In 1895 Lambe reported on 60 specimens from Alaska. He stated that the maximum length of the tylostyles for these was 406 µm. This size is much closer to those we provide in Table 13 which also includes two specimens from Alaska.
De Laubenfels (1961) reported Choanites suberea var. lata as common and frequently occurring on hermit crab shells in the vicinity of Friday Harbor, Washington. He reported tylostyles ranging from 5 µm x 280 Μm to 6 µm x 180 µm (a misprint for 380 or 480?) and centrotylote microstrongyles 24 µm long.
We compared our specimens with those reported from central and southern California. De Laubenfels (1932) gave spicule measurements for two specimens from central and southern California as 70 µm x 5 µm to 590 µm x 12 µm. He does not state whether hermit crabs or their cavities were present.
Bakus & Green (1987) described a sponge from 183 m off Pt. Conception, California. It was growing on a gastropod shell. It had two classes of tylostyles 190 –(424)– 680 µm x 7 –(09)– 11 µm and 120 –(413)– 657 µm x 1 –(3)– 4 µm and centrotylote strongyles 20 –(30)– 48 µm by 1 –(2)– 2.5 µm. They considered it as a member of S. ficus. The mean and maximum length of the tylostyles are 30 % and 75 % greater than the maximum mean and maximum longest lengths we measured in BC material.
Lee et al. (2007) described Suberites latus from southern to northern California as subtidal and often associated with a hermit crab or mollusk shell. The tylostyle range was from 90 –(197–321)– 680 µm x 2.5–5.1 –(8.6)– 12 µm. Centrotylote strongyles were rare. They ranged from 12.3 –(21.2–28.5)– 56 µm. The maximum length of the tylostyles was again 75 % longer (680 µm) than the longest found by us (394 µm).
De Laubenfels (1935) described Suberites mineri from the surveys of the Albatross during 1911 off Baja California. No data were recorded on precise locality or depth, and while the Albatross was working off the Baja California coast, stations ranged from the intertidal to depths of 3200 m (Anon. 1921). According to de Laubenfels, microstrongyles were abundant, ranging from 18–36 µm in length, but tylostyles were of one kind only, averaging 340 µm by 10 µm. He found no small cortical tylostyles which would preclude the species from membership in the genus Suberites as defined by van Soest (2002) in the Systema Porifera. One of our reviewers commented that the species was common on the flat bottoms of the Mexican Pacific area; but if its spicule complement is as described by de Laubenfels, it is not closely related to Suberites latus.
Is S. latus a distinct species, or a subspecies of a cosmopolitan S. ficus ? The types and size range of spicules given by van Soest (2002) for S. ficus (small tylostyles 100–250 µm, large tylostyles 350–500 x 5–10 µm, centrotylote microstrongyles 15–50 µm) approximate those in S. latus from the NE Pacific. Van Soest (2002) further observed that the large tylostyles of S. ficus occur in a wide size range. This is comparable to the wide variation in maximum size reported above by various authors for S. latus. Solé-Cava & Thorpe (1986) reported that three morphotypes of S. ficus from the Irish Sea had spicule types and mean sizes which were indistinguishable. However, they had significant genetic differences which, since they were sympatric, indicated genetic isolation. They concluded that the morphotypes represent three separate species within a S. ficus complex. Van Soest (2002) agreed that S. ficus is very likely to be a complex of sibling species.
Conclusions. Van Soest et al. (2012) consider S. latus to be a valid species separate from S. ficus (World Porifera Database, consulted November 2012). We concur and suggest that all sponges with hermit crabs, two size classes of tylostyles and centrotylote strongyles from southern California to Alaska are members of a S. latus species complex. The two Suberites latus populations from southern to central California, and BC to Alaska may represent sibling species. This species complex would be a good candidate for DNA bar coding.
Bathymetric range. 6–183 m depth.
Geographic distribution. Southern California to the Bering Sea (Alaska, USA) and possibly north.
Ecology. The association of Suberites latus with Pagurus stevensae provides the hermit crab with a home which can be enlarged as it grows. The mobile sponge can range beyond rock substrate onto soft or unconsolidated sediment. The styloid ends of those tylostyles ending at the hermit crab canal may be responsible for the slippery surface which could aid the rapid retreat of the hermit crab from predators. The gastropod shell on which the sponge initially settled has disappeared in larger sponges (de Laubenfels 1961 and pers. observation).