Chlorostoma Funebralis (=Tegula Funebralis) Phylum: Mollusca Class: Gastropoda, Prosbranchia Order: Archeogastropoda the Black Turban Or Top Shell Snail (A
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View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by University of Oregon Scholars' Bank Chlorostoma funebralis (=Tegula funebralis) Phylum: Mollusca Class: Gastropoda, Prosbranchia Order: Archeogastropoda The black turban or top shell snail (A. Adams, 1855) Family: Trochidae, Monodontinae Description Possible Misidentifications Size—to 50 mm or more high (Carlton and The Trochidae are herbivorous, conical Roth 1975), usually less than 25 mm (Keep snails, pearly within, with round, entire 1935); this specimen 20 mm diameter, 17 mm apertures and thin horny circular opercula high. (Griffith 1975). The Turbinidae, a similar Color—exterior purplish-black, not shiny; with family, are also conical, but they have a white eroded apex. Gray when dry. Interior calcareous operculum, and are represented white with a black margin; a pearly or here only by Astraea, a large subtidal and "rainbow" deep interior patch. White around offshore species. columella (McLean 1969) (fig. 1) The other common genus of the Trochidae Shell Shape—strong; 4 inflated whorls; rather is Calliostoma, a conical top shell, which is top-shaped, (conical) with a flat base; round distinguished from Chlorostoma chiefly by its aperture, nearly round, horny operculum: lack of denticles or nodes on the columella. family Trochidae (Griffith 1975). Small snails Its whorls are not inflated like Chlorostoma's. are about as high as wide (figs. 1, 2); older Calliostoma is found on the outer shores, not ones become higher than wide (Frank in bays; it has many spiral ribs, no umbilicus, 1965b). and various distinctive colorations. Sculpture—below the suture is an impressed Snails of the genus Chlorostoma have line (Oldroyd 1924), or a scaly band (Carlton strong columellar nodes, a round, thin, horny and Roth 1975): "foliaceous incremental operculum with many spiral lines, and a lamellae" (Oldroyd 1924) (figs. 1. 2). Whorls pearly interior. They sometimes have a "spirally lirate," i.e. having up to 17 thread-like periostracum. The 3 other species of spiral lines (figs. 1, 2); sometimes smooth Chlorostoma found on the Pacific coast are except for base, or strongly sculptured above not known to be estuarine: (fig. 2). Tegula montereyi probably does not occur Umbilicus—covered by a callus, nearly above Bolinas Bay, north of San Francisco; it always closed (Carlton and Roth 1975) (fig. occupies the low intertidal off-shore zone, 3). Specimens with an open umbilicus do not often in kelp beds. This species is brown, with have a flange between umbilicus and a strong, open umbilicus and a strictly conical aperture. (not inflated) profile. Columella—spirally twisted (Oldroyd 1924), Tegula pulligo, the dusky turban, occurs in with 2 denticles (nodes) near base (fig. 3), the low intertidal in California; it is the lower node worn or indistinct. dominant Tegula in Puget Sound (Griffith Aperture—round, complete; no anterior notch 3 1975), where it occurs in open coasts and in or canal (fig. 3): aperture length less than /4 protected situations (Kozloff 1974a). T. pulligo shell length. has an open umbilicus with the inner lip Outer Lip—smooth, black-rimmed, without produced into a flange (it is closed in T. sculpture (fig. 3). funebralis). It has a brown (not purple or Operculum—thin; round, numerous spiral black) periostracum; its basic color is brown lines; horny, not calcareous (fig. 4). or gray, sometimes with orange, white or Radula—with a single central tooth; 5-7 brown spots on the edge. Its habitat is open pointed lateral teeth, 8-10 marginal teeth (fig. rocky beaches (Griffith 1975). 6). Chlorostoma brunnea, the brown turban, is Foot—long, relatively narrow; with epipodal the closest to C. funebralis in Oregon; it does tentacles along sides: family Trochidae (4 on not seem to occur in Puget Sound (Kozloff each side: species funebralis (fig. 5). 1974a), and is very common on the outer shores in Oregon and around San Francisco (Packard 1918). It has only one node on the Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected] columella, as opposed to C. funebralis' two; mm diameter. Breeding probably once a year its shell is brown or orange brown, and it lacks (Paine 1979); reproductive size of snails 14 the scaly subsutural band of funebralis mm (Paine 1971). Planktonic veliger larvae (Carlton and Roth 1975). C. brunnea is found emerge on 7th day, settle 12th day. Long life of lower in the intertidal than funebralis, or in off- T. funebralis ensures increased lifetime shore kelp beds near the surface; probably reproductive effort (Frank 1975). never in estuaries. Longevity—lives up to 30 years; average age Tegula gallina, the speckled tegula, is gray may be 10 years (Frank 1975). to green, lacks the scaly subsutural band, and Growth Rate—young snails grow rapidly: is found south of Santa Barbara. It is closely from 4-5.6 mm and 27 mg average weight related to C. funebralis; the radulae are quite (June) to 5.6-9.8 mm. 177.3 mg (following similar (Merriman 1967). March) (Morris et al 1980). California snails do not show growth rings of Oregon snails, Ecological Information which in older animals reveal an annual Range—Vancouver, B.C., to central Baja winter cessation of growth (Frank 1975). California (McLean 1969). Food—"a catholic feeder" (Frank 1975): Local Distribution—marine portions of large almost any common alga. Prefers Macrocystis Oregon. estuaries; Coos Bay: Pigeon Point. integrifolia, Nereocystis luetkeana, Habitat—avoids exposed outer coast Rhodoglossum affine, Gigartina canaliculata: situations although it is found in rocky i.e. fleshy forms. If not available, will eat protected outer tidepools (Carlton and Roth encrusting green alga, Ralfsia pacifica, 1975); marine portions of estuaries in rocky detritus (Abbott et al 1964). situations amongst seaweed (Griffith 1975). Predators—Pisaster ochraceus in low Strongly built: can withstand surf. Females intertidal. Although Chlorostoma is not its found in more exposed places than males at preferred prey, Pisaster can consume over ¼ low tide (Frank 1975). Species is negatively the available snails (Frank 1965b). Possibly phototactic: seeks the light (Morris et al 1980). limpet Collisella; carnivorous snail Nucella; Salinity—collected at 30 ‰ salt. Cannot crab Cancer antennarius. withstand continued exposure to low salinity. Behavior—larger animals migrate to lower Temperature—found in temperate waters intertidal. Species is sedentary, aggregates at only. With black color can get quite warm low tide, moves up to rock tops at nighttime during exposure to sun at low tides. high tides (not diurnal ones) (Morris et al Tidal Level—on outer shores, most common 1980). Territory: tends to live in a radius of at high inter-tidal (2-0 m) (Frank 1975); found about 1.5 m for months; a daily movement of in midintertidal as well." In estuary found at 0- about 1m (Frank 1975). Snails move well on +1 ft. Small snails settle high, live there 5-6 rocks, are clumsy on sand. They place years, then migrate to lower levels (to +0.6- - pebbles on the foot to alter balance (Morris et 0.2 m) (Paine 1979). al 1980). Escape predators by sensory Associates—on outer coast: slipper shell perception (seastars), or by crawling onto top Crepidula and several limpets (Collisella), of predator's shell (carnivorous snails). which can be predatory. Empty shells used by hermit crabs. Bibliography 1. ABBOTT, D. P., L. R. BLINKS, J. H. Quantitative Information PHILLIPS, and R. H. STOHLER. Weight—this specimen 4g wet, with shell. 1964. The biology of Tegula Abundance—most abundant mid-intertidal funebralis. The Veliger. 6 Supplement. grazer (Frank 1975). 2. CARLTON, J. T., and B. ROTH. 1975. Phylum Mollusca: Shelled Gastropods, Life History Information p. 467-514. In: Light's manual; Reproduction—dioecious; eggs and sperm intertidal invertebrates of the central exuded into water. Sexes can be determined California coast. S. F. Light, R. I. by color of foot sole: males are light, females Smith, and J. T. Carlton (eds.). darker; female gonad bright green from egg University of California Press, yolk. Egg masses gelatinous, about 3 mm Berkeley. diameter; several hundred eggs, about 0.19 3. FRANK, P. W. 1965b. Shell growth in Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected] a natural population of the turban snail 14. ——.1979. The Pisaster-Tegula Tegula funebralis. Growth. 29:395- interaction: Prey patches, predator 403. food preference and intertidal 4. ——. 1975. Latitudinal variation in the community structure. Ecology. 50:950- life history features of Tegula 961. funebralis (Prosobranchia: Trochidae). Marine Biology. 31:181-192. 5. FRITCHMAN, H. K. 1965. The radulae of Tegula species from the west coast of North America and suggested intrageneric relationship. The Veliger. 8:11-14. 6. GRIFFITH, L. M. 1975. The intertidal univalves of Britsh Columbia. British Columbian Provincial Museum Handbook. 26:1-101. 7. KEEP, J., J. Longstreth (eds). 1935. West coast shells; a description in familiar terms of principal marine, fresh-water, and land mollusks of the United States, British Columbia, and Alaska, found west of the Sierra. Calif., Stanford University Press; London, H. Milford, Oxford University Press, Stanford University. 8. KOZLOFF, E. N. 1974a. Keys to the marine invertebrates of Puget Sound, the San Juan Archipelago, and adjacent regions. University of Washington Press, Seattle & London. 9. MCLEAN, J. H. 1969. Marine shells of southern California. [Los Angeles] Los Angeles County Museum of Natural History. 10. MERRIMAN, J. A. 1967. Systematic implications of radular structures of west cost species of Tegula. The Veliger. 9:399-403. 11. MORRIS, R. H., D. P. ABBOTT, and E. C. HADERLIE. 1980. Intertidal invertebrates of California. Stanford University Press, Stanford, California. 12. OLDROYD, I. S. 1924. Marine shells of Puget Sound and vicinity. University of Washington Press, Seattle. 13. PAINE, R. T.