||Echinolittorina jamaicensis Adams, 1850
||Littorina glaucocincta Mörch 1876
Littorina jamaicensis C.B. Adams 1850
Littorina riisei Mörch 1876
Nodilittorina mordax Bandel & Kadolsky 1982
Nodilittorina riisei Mörch 1876
A part of the Echinolittorina ziczac species complex, Echinolittorina jamacensis is so similar in appearance to its close relatives E. ziczac and E. angustior that genetic analysis is sometimes necessary to differentiate between them. It is also frequently misidentified as E. lineolata, even in the literature, although true E. lineolata do not occur in the Indian River Lagoon or surrounding areas. (COMMENT: What region?) (Reid, 2009; Janson, 1985). In most respects E. jamacensis matches descriptions of E. ziczac; a small, ridged, roughly conical littorinid with brown markings on a white base color, with a dark, purplish brown inner shell and dark brown operculum. (Abbot, 1954; Smith 1951) Its body is also dark brown, small, and rounded, with two small tentacles.
Characteristics differentiating E. jamaicensis from true E. ziczac and E. angustior are, taken together, a shell length greater than or equal to 5.8 millimeters, 6-8 primary spiral grooves between sutures, about 1.46 ratio of shell height to width, clear, marked spiral striation with approximately 12 dark brown lines on each whorl, a single band of color on the aperture's edge, and a wavy shell pattern (Reid, 2009; Janson, 1985). None of these characteristics can individually be used to correctly identify E. jamaicensis, since a member of another species can have one or several of these characteristics, or an E. jamaicensis can lack some (Janson, 1985).
HABITAT AND DISTRIBUTION
Habitat & Regional Occurence:
Like the other members of the E. ziczac complex,E. jamaicensis occurs throughout South Florida, although it seems to be more common in the northern part of the ziczac-complex range. Locally it can be found in Sebastian and the St. Lucie Inlets (Janson, 1985). It is frequently found mixed with E. ziczac and E. angustior (Janson, 1985), and so can be assumed to prefer the same habitat; i.e., hard substratum in the higher rocky intertidal zone, in areas prone to regular wetting but only occasional submersion (Stephenson and Stephenson, 1950). Differences in distribution between E. jamaicensis and the other ziczac-complex littorinids may be due to the effect of ocean current patterns on settling larvae (Janson, 1985).
Based on the high mortality rate occurring during colder months, Echinolittorina jamaicensis appears to be temperature sensitive and responds poorly to lower temperatures typical of southern Florida winters.
LIFE HISTORY AND POPULATION BIOLOGY
Size, LifeSpan & Reproduction
The life histories and reproductive habits of all three ziczac-complex species are similar (Borkowski, 1973). E. jamaicensis and its relatives seem to have an average lifespan of two years (Borkowski, 1973). Planktonic juveniles of E. jamaicensis and the other ziczac-complex species reach half a millimeter in height, then settle out of the water column on the upper rocky intertidal. This usually takes place in the late summer or fall (Borkowski, 1973). From the time they settle until the beginning of the following summer, young snails feed and grow until reaching adult size somewhere between December and May. During these winter months, high mortality in adult snails occurs, up to 80% of the incumbent population. Initial growth rates are slow and rapidly increase until peaking in the late spring or early summer. At this time,, their growth dramatically slows and they become sexually mature. Many individuals appear to put off spawning until their second year (Borkowski, 1973).
During copulation, males deposit sperm in the female's bursa copulatrix. Some of this sperm is transferred to the seminal receptacle where it is stored until the female fertilizes its eggs. Sperm not transferred to the seminal receptacle is broken down and digested by the female (Borkowski, 1973). Mating can occur at any time throughout the year and does not seem dependent on environmental conditions. Larval release appears to correspond to lunar patterns associated high tides even when individuals are removed from their habitat and placed in controlled laboratory conditions.
No information is available at this time
Like most littorinids, E. jamaicensis is herbivorous scrapping the surface of the rocks on which it lives in order to graze on microalgae. E. jamaicensis, may coincidentally also consume detritus, as well asbarnacle spat, attached egg capsules, and small amounts of sand and rock while scraping the surface (Norton et. al., 1990). Predators of E. jamaicensis may include crabs, waterbirds, fish and predatory gastropods.
No information is available at this time
Abbot, R. Tucker. 1989. American Seashells. D. Van. Nostrand Company Inc. Toronto.
Borkowski, Thomas V. 1973. Growth, Mortality, and Productivity of South Floridian Littorinidae (Gastropoda: Prosobranchia) Bulletin of Marine Science, 24: 409-438.
Janson, Kerstin. 1985. Genetic Variation in Three Species of Caribbean Periwinkles, Littorina angustior, L. lineolata, and L. ziczac (Gastropoda, Prosobranchia). Bulletin of Marine Science 37: 871-879.
Norton, T.A., S.J. Hawkins, N.L. Manley, G.A. Williams, D.C. Watson. 1990. Scraping a living: a review of littorinid grazing. Hydrobiologia 193: 117-138.
Reid, D. G. 2009. The genus Echinolittorina Habe, 1956 (Gastropoda: Littorinidae) in the western Atlantic Ocean. Zootaxa 2184: 1-103.
Smith, Maxwell. 1951. East Coast Marine Shells, 4th Ed. Edwards Brothers Inc. Ann Arbor, Michigan
Stephenson, T. A., and A. Stephenson. 1950. Life between Tide Marks in North America: the Florida Keys. Journal of Ecology, 38: 354-402.
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Page last updated: 22 October 2012