Assiminea Californica (=Syncera Ranslucens) Class: Gastropoda, Prosobranchia Order: Mesogastropoda a Small Salt Marsh Snail (Tryon, 1865) Family: Assimineidae

Phylum: Mollusca Assiminea californica (=Syncera ranslucens) Class: Gastropoda, Prosobranchia Order: Mesogastropoda A small salt marsh snail (Tryon, 1865) Family: Assimineidae Description Size—less than 4 mm high; most specimens horizontal lines. The animal has long collected near 3 mm. tentacles, not Assiminea's unusual ocular Color—glossy chestnut (Keen 1971), smooth, peduncles. Littorina scutulata, the checkered transparent (largest whorl); interior porcelain- littorine, is occasionally found in the saltier like, not pearly; spire often almost black (Coos parts of marshes. It is quite a bit larger than Bay specimens); animal white with black all the preceding snails, and is patterned on markings (fig. 4). its exterior and purple inside. Shell Shape—5 whorls: rounded, convex; globose to turbinate (Keen and Coan 1974), Ecological Information taller than wide; aperture subcircular, without Range—Vancouver Island, British Columbia, notch or canal; inner lip spread out as a small to Cabo San Lucas, Baja California (Keen thickened callus (Keen and Coan 1974) (fig. 1971). 3). Local Distribution—Coos Bay, many Columella—continuous with inner lip: no stations: South Slough, Haynes Inlet. shelf, no folds, appressed to whorl. Spreads Habitat—under driftwood, debris, Salicornia, into callus. (fig. 3). in mud. Animal—eyes on short ocular peduncles, no Salinity—generally a wide toleration of tentacles: family Assimineidae (Keen 1971) salinities: to 2.4 ‰ seawater; possibly to 16 ‰ (fig. 4). Radula with 3 basal cusps on both (Matthews 1979). sides of central plate: genus Assiminea (not Temperature—varied (salt marsh figured). temperatures). Operculum—very thin, transparent, Tidal Level—family Assimineidae are subspiral, convex (fig. 2). intertidal4; all live above the low tide level; this species likes upper, usually dry parts of the Possible Misidentifications marsh, about 3-4 feet (South Slough, Coos Assiminea californica is one of a small Bay). association of salt marsh snails. Within our Associates—littorines L. sitkana, L. (A.) range it is often found with or near Littorina newcombiana, pulmonate Ovatella myosotis, (Algamorda) newcombiana. This is a slightly amphipod Traskorchestia traskiana; plants: larger littorine (to 6 mm) with 4 whorls, a Salicornia, Distichilis, Fucus. nearly circular aperture, and with a simple chink between the large whorl and inner lip. Quantitative Information The general shape and appearance of the Weight— two gastropods is quite similar. L. (A.) Abundance—common in Salicornia marshes newcombiana does not have ocular (Smith and Carlton 1975). peduncles. A 2nd snail common found in salt marshes Life History Information is Ovatella myosotis, a pulmonate of rather Reproduction— olive shape, up to 8 mm long. It is Growth Rate— subcylindrical, not turbinate, with a short Longevity— spire, three columellar folds, and no Food— operculum. (See plate) Predators—fish: many snails found in gut Littorine snails are larger than Assiminea, content analysis (Coos Bay) (Matthews 1979). but can be superficially similar: Littorina sitkana, often found in this association, is Bibliography globose, almost as wide as long, and has 1. KEEN, A. M. 1971. Sea shells of either heavy striated sculpture or dark Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected] tropical west America; marine mollusks from Baja California to Peru. Stanford University Press, Stanford. 2. KEEN, A. M., and E. COAN. 1974. Marine Molluscan Genera of Western North America: An Illustrated Key. Stanford University Press, Stanford, California. 3. MATTHEWS, R. 1979. A comparative study of preferred salinities among South Slough snails. Oregon Institute of Marine Biology (University of Oregon). Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected] Digitized 2010 – Last Updated 1979 – E-mail corrections to [email protected] .

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