Cliona lobata Hancock 1849

Cliona lobata Hancock, 1849 Figs. 3 A–E; 4A–G Cliona howsei Hancock, 1849; Topsent 1891. Material examined. KML 1012, sta. 07-11-15.1 212, Rapid Assessment Inventory of Species, Point Grenville, WA, (47° 18.3′N, 124° 16.6′W), low intertidal, Aug. 10, 2002, coll. J. Goddard, 1 specimen in skeleton of a dictyoceratid sponge; RBCM 981-144-6, sta. PBS No. 2242-2S, shore of Nootka I., BC, (approx. 49° 40′N, 126° 30′W), intertidal, Jul./ Aug. 1934, coll. W.A. Clemens, 1 specimen on barnacle; KML 1016, sta. 46-97, Razor Bank Point, Hollister Ranch, Santa Barbara, CA, (34° 26.0′N, 119° 52.2′W), depth unknown, Nov. 18, 1975, coll. F. Hochberg, 1 specimen. Description. Macroscopic features. KML 1012; specimen up to 2 cm high extending over several cm2 as a mat in the field, beta stage. In a 1 cm x 2 cm portion the surface is penetrated by four holes into which the oscula have retracted. One hole is 1.1 mm in diameter, the other three are 0.35 mm in diameter; oscula closed. Much of the surface covered by pore sieves which in the preserved material are flush with the surface (Fig. 3 B); sieve formed by a series of arched fingerlike structures connected by fine filaments; spaces between the intersections represent the pores averaging about 22 µm in diameter; 10–20 pores together form the sieve covering 1 to 2 ostia each 55–92 µm in diameter, and spaced at intervals of 185–440 µm. Ectosome 0.2–0.5 mm thick; where thin, forms dimples over tips of fibres spaced at 90 to 100 µm intervals (Fig. 3 A). Ectosome with tylostyles aligned with points extending about 100 µm beyond the surface. Mat of anastomosing fibres extends below the C. lobata ectosome two or more cm, colour golden brown, consistency unyielding and almost rock hard in alcohol. Fibres form tight mesh with openings of 180–240 µm (Fig. 3 C); all interfibre spaces filled by C. lobata choanosome and a few sand grains; fibres cored, knarled and lumpy; secondary fibres dominate; 60–250 µm diameter; laminated in part (Fig. 3 D); and free of debris except for occasional tylostyles incorporated into walls (Fig. 3 E). Primary fibres 350–900 µm diameter formed from fusion of secondary fibres to form lumpy plates about 1 mm below the surface. No tertiary fibres; no identifiable ectosome. No evident excavation chambers. Colour in life dull yellow. RBCM 981-144-6: this specimen has been misplaced but is included in the material examined in anticipation of its recovery. KML 1016: substrate possibly coralline algae, largely consumed, cannot identify remnants. Spicules. Spicules from the three specimens qualitatively similar; tylostyle heads varying from tylote and subtylote (Fig. 4 A, B, D) to stylote with subterminal swelling (Fig. 4 E). Some tylostyles with multilobate heads (Fig. 4 C). Spirasters in two size classes, large with shaft bent back and forth, typically 9–10 times; the spines roughly following a spiral around the shaft. Small spirasters with spines more equally distributed along the shaft, which still bends 2–3 times. Large spirasters (Fig. 4 G–I) with relatively sparse spines, their lengths equal to or greater than one half the shaft diameter. Small spirasters (Fig. 4 F) with relatively abundant spines, their length less than one-half the shaft diameter. In larger spirasters length to diameter ratio varies considerably but greater than 10 to 1; in small spirasters length to diameter ratio less than 5 to 1. The two size classes may or may not overlap. RBCM 981-144-6 Remarks. KML 1012 is the first published record in the NE Pacific of a boring clionaid occurring within a reticulum of coarse spongin fibres. Pat Bergquist in a letter to Jeff Goddard, the discoverer, (pers. comm.) suggested that it might be a chimera of a Cliona sp. and a dictyoceratid close to, but distinct from Petrosaspongia. Chimeras between sponge species in the field are extremely rare (Little 1966, Maldonado 1998). However, epizoics among sponges are more common (Rützler 1970, Sarà 1970, Wulff 2006). Spheciospongia symbiotica Hechtel, 1984 is an example of an association between a clionaid and a verongid. Two species of Petrosaspongia have been described, P. nigra Bergquist, 1995 from New Caledonia and P. pharmamari Uriz & Cebrian, 2006 from the Canary Islands. The fibre skeleton of KML 1012 is similar to these two species in relative proportion of primary and secondary fibres and their diameters, the presence of foreign debris in primary but not secondary fibres, coring in primary fibres, laminated secondary fibres, and a tight meshwork of anastomosing fibres. It has a very hard, incompressible skeleton unique to the genus. However, the KML 1012 skeleton differs significantly from the two known species in being knarled and lumpy rather than relatively smooth and in having cored secondary fibres. Our specimen was tightly adherent to the rock substrate and had a rock-like texture. We suggest that it could have provided a stable, attached skeletal framework (perhaps with a shell-sand component) for the C. lobata. In a similar association the poecilosclerid Desmacella austini Lehnert, Conway, Barrie & Krautter 2005 occupies the fused glass skeleton remaining when all or a portion of the hexactinellid Aphrocallistes vastus Schulze, 1887 dies (Austin 2012, Lehnert et al. 2005). Some of the fibres had incorporated tylostyles into the spongin coating. These spicules were the same form and size as in C. lobata. Therefore, the dicyoceratid was alive when it was first invaded by C. lobata. However, only the fibres of the dictyoceratid were present when the sponge was collected. Samples of the choanosome and ectosome from all parts of the specimen had large populations of tylostyles and were, therefore, unlikely to represent part of the dictyoceratid. At least superficially the C. lobata would be classified as a β form, with an ectosome over the surface. We are unable to find any reports of a β form of C. lobata. However, the lack of a solid layer of calcium carbonate would disallow the development of exclusively subsurface galleries with only papillae at the surface. The papillae with pore sieves are flush with the surface in our specimen while Topsent (1888, 1900) described them as up to 230 µm in height with a diameter of 400 µm in exhalent papillae and 150–170 µm in inhalant papillae. It is likely that most species of Cliona have contractile papillae (e.g. Fig. 1 A, B, C). Von Lendenfeld (1897) illustrated a pore sieve papilla flush with the surface of a coralline alga in a specimen of Pione vastifica while Goreau & Hartman (1963) illustrated an expanded pore sieve papilla and oscular papilla in Cliona celata. Pore sieves in the related Spheciospongia are 15 to 70 times larger than those in Cliona (e.g., Rützler 2002, Carballo et al. 2004, de Laubenfels 1930). In Cliona we suggest that the pores are of an appropriate size (22 µm) to filter out extracted calcium carbonate chips (e.g., 20–60 µm per Rützler & Rieger 1973) during burrowing. The tylostyle sizes were fairly similar among the three specimens. However RBCM 981-144-6 (from Nootka I., BC) had a spiraster which was much longer (99 Μm) than any others. This spiraster was the same diameter as the shorter ones but had 13 twists or zig-zags compared to up to 10 in shorter spirasters. Arndt (1935) reported that when gemmules are formed in C. lobata, spirasters of 126 Μm or more are covering their surfaces. We may have a similar case in the Nootka I. specimen. The sizes of the small spirasters were similar among the three samples. Table 1 lists descriptions of specimens regarded as Cliona lobata. Records without descriptions or repeating those of others are largely excluded. When Hancock (1849) described C. lobata from Guernsey (English Channel) he reported that tylostyle heads were often irregularly rounded, sometimes slightly elliptical, and generally not exactly terminal. This conforms to our material. However, Hancock gave the tylostyle length as 1/100th of an inch (= 254 µm) which is considerably longer than the maximum tylostyle length in our material. He did not mention any spirasters. In 1867 Hancock reported spirasters from a specimen of C. lobata obtained from the west coast of Scotland. He described the spirasters as cylindrical, rather stout, arched, zig-zagged, strongly spined, ends obtuse and about 50 µm in length. These are comparable in form to the large spiraster in our material. Hancock did not mention a second type of spiraster. Rützler & Stone (1986) re-examined the spicule slides Hancock had made 120 years earlier. For the holotype of C. lobata they discovered that the tylostyles were shorter than Hancock had indicated (180 and 200 µm instead of 250 µm). They also stated that there were apparently two size classes of spirasters averaging 50 µm and 15 µm in length). These are evident in their Fig. 3 C. These average sizes are approximately the same as in our material except for a larger average size (65 Μm) of the large spirasters in RBCM 981-144-6 from BC. Topsent (1900) described material from France as C. lobata. The tylostyles are similar in form and also in size to our material (range 139–(158)–178 µm). He found the spirasters in the same individual varied in length and in spination. Topsent (1888, 1900) illustrated two basic types of spirasters which appear identical to those in our material. Based on his illustration the large spiraster ranged from 47 Μm or less up to 65 Μm, about the same as in KML 1016 but less than in KML 1012 and RBM 981-144-6. The small spirasters ranged from 10 µm to 30 µm, about the same as in our material. Stephens (1915) found a Cliona off Cape Town, South Africa which she said agreed in every particular with C. lobata as described by Topsent (1900). In the NW Atlantic, Old (1941) identified material collected from Long Island, NY to Chesapeake Bay (VA) as C. lobata. However, he did not describe or figure two different categories of spirasters. Hartman (1958) found C. lobata to be common on oyster bed

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