Paul Norwood, USA
Info
Littorina sitkana is a tiny periwinkle native to the entire North Pacific coast.
The periwinkle is usually found in sheltered areas, on rocks, in crevices, or among algae such as seaweed, but can also be found on pilings and sea grass.
Higher concentrations can be found in areas protected from direct sunlight (photo). Often found in and around.
The species has several ecotypes along the wave-protected coasts of the northeastern Pacific, where the demography and life history of Littorina sitkana vary depending on the tidal zone.
Snails living in the lower intertidal zone reach sexual maturity at a smaller size and do not grow as large as individuals from the upper intertidal zone.
These differences in life cycle may be related to the risk of predation by the associated predatory crab, Cancer productus (Randall).
Snails in the lower intertidal zone may divert energy to reproductive organs more quickly, at the expense of somatic growth, as the risk of becoming prey to predators tends to increase with snail size and is significantly greater in the lower intertidal zone than in the upper.
Interestingly, snails originating from the upper coastal zone grow faster than individuals from the lower coastal zone when placed in the same location in the intertidal zone, suggesting that some of these phenotypic differences may have a genetic basis.
Description:
As with other snails of the family Littorinidae, the shell is spherical with a short spiral and a height approximately equal to or slightly greater than the diameter.
There is neither a siphon notch nor an anal notch, the operculum is horn-like, and the interior of the shell is not nacreous.
The columella has no folds or ribs, and there is no umbilicus.
Littorina sitkana has a diameter that is almost equal to its height and sometimes has pronounced spiral ribs; it has only about 4 whorls.
The tip is not pointed.
The aperture is large and almost circular, and the interior is purple or brown; the columella is whitish.
The outside is light brown to gray or black.
Synonyms:
Litorina gouldiana Weinkauff, 1882 · unaccepted
Litorina sitchana [sic] · unaccepted > misspelling - incorrect subsequent spelling
Litorina sitkana R. A. Philippi, 1846 · unaccepted (incorrect spelling of genus name)
Litorina sitkana var. atkana Dall, 1886 · unaccepted > superseded combination
Litorina sulcata P. P. Carpenter, 1864 · unaccepted
Litorina tenebrosa f. depressior Schrenk, 1867 · unaccepted
Litorina tenebrosa var. albida Schrenk, 1867 · unaccepted
Litorina tenebrosa var. fasciata Schrenk, 1867 · unaccepted
Litorina tenebrosa var. fusca Schrenk, 1867 · unaccepted
Litorina tenebrosa var. laevigata Schrenk, 1867 · unaccepted
Litorina terebrosa (Montagu, 1803) · unaccepted (erroneous spelling of the species...)
Littorina (Littorina) kurila Middendorff, 1848 · unaccepted > superseded combination
Littorina (Littorina) sitchana [sic] · unaccepted > misspelling - incorrect subsequent spelling
Littorina (Neritrema) sitkana R. A. Philippi, 1846 · alternative representation
Littorina atkana Dall, 1886 · unaccepted > junior subjective synonym
Littorina castanea A. Adams & Reeve, 1850 · unaccepted
Littorina cincta A. Gould, 1847 · unaccepted (junior synonym)
Littorina kurila Middendorff, 1848 · unaccepted
Littorina kurila var. costulata Middendorff, 1851 · unaccepted
Littorina kurila var. fasciatus Middendorff, 1851 · unaccepted
Littorina kurila var. fuscus Middendorff, 1851 · unaccepted
Littorina kurila var. griseolacteus Middendorff, 1851 · unaccepted
Littorina kurila var. zonatus Middendorff, 1851 · unaccepted
Littorina sitchana [sic] · unaccepted > misspelling - incorrect subsequent spelling
Littorina sitchana kurila Middendorff, 1848 · unaccepted > junior subjective synonym
Littorina sitchana subtenebrosa Middendorff, 1848 · unaccepted > junior subjective synonym
Littorina sitchana var. castaneus Middendorff, 1849 · unaccepted
Littorina sitchana var. zonatus Middendorff, 1849 · unaccepted
Littorina sitchensis G. Nevill, 1885 · unaccepted
Littorina sitkana var. subtenebrosa Middendorff, 1848 · unaccepted > junior subjective synonym
Littorina subtenebrosa Middendorff, 1848 · unaccepted
Neritrema sitkana (R. A. Philippi, 1846) · unaccepted > junior subjective synonym
Neritrema sitkana kurila (Middendorff, 1848) · unaccepted > junior subjective synonym
For sources, see further links.
The periwinkle is usually found in sheltered areas, on rocks, in crevices, or among algae such as seaweed, but can also be found on pilings and sea grass.
Higher concentrations can be found in areas protected from direct sunlight (photo). Often found in and around.
The species has several ecotypes along the wave-protected coasts of the northeastern Pacific, where the demography and life history of Littorina sitkana vary depending on the tidal zone.
Snails living in the lower intertidal zone reach sexual maturity at a smaller size and do not grow as large as individuals from the upper intertidal zone.
These differences in life cycle may be related to the risk of predation by the associated predatory crab, Cancer productus (Randall).
Snails in the lower intertidal zone may divert energy to reproductive organs more quickly, at the expense of somatic growth, as the risk of becoming prey to predators tends to increase with snail size and is significantly greater in the lower intertidal zone than in the upper.
Interestingly, snails originating from the upper coastal zone grow faster than individuals from the lower coastal zone when placed in the same location in the intertidal zone, suggesting that some of these phenotypic differences may have a genetic basis.
Description:
As with other snails of the family Littorinidae, the shell is spherical with a short spiral and a height approximately equal to or slightly greater than the diameter.
There is neither a siphon notch nor an anal notch, the operculum is horn-like, and the interior of the shell is not nacreous.
The columella has no folds or ribs, and there is no umbilicus.
Littorina sitkana has a diameter that is almost equal to its height and sometimes has pronounced spiral ribs; it has only about 4 whorls.
The tip is not pointed.
The aperture is large and almost circular, and the interior is purple or brown; the columella is whitish.
The outside is light brown to gray or black.
Synonyms:
Litorina gouldiana Weinkauff, 1882 · unaccepted
Litorina sitchana [sic] · unaccepted > misspelling - incorrect subsequent spelling
Litorina sitkana R. A. Philippi, 1846 · unaccepted (incorrect spelling of genus name)
Litorina sitkana var. atkana Dall, 1886 · unaccepted > superseded combination
Litorina sulcata P. P. Carpenter, 1864 · unaccepted
Litorina tenebrosa f. depressior Schrenk, 1867 · unaccepted
Litorina tenebrosa var. albida Schrenk, 1867 · unaccepted
Litorina tenebrosa var. fasciata Schrenk, 1867 · unaccepted
Litorina tenebrosa var. fusca Schrenk, 1867 · unaccepted
Litorina tenebrosa var. laevigata Schrenk, 1867 · unaccepted
Litorina terebrosa (Montagu, 1803) · unaccepted (erroneous spelling of the species...)
Littorina (Littorina) kurila Middendorff, 1848 · unaccepted > superseded combination
Littorina (Littorina) sitchana [sic] · unaccepted > misspelling - incorrect subsequent spelling
Littorina (Neritrema) sitkana R. A. Philippi, 1846 · alternative representation
Littorina atkana Dall, 1886 · unaccepted > junior subjective synonym
Littorina castanea A. Adams & Reeve, 1850 · unaccepted
Littorina cincta A. Gould, 1847 · unaccepted (junior synonym)
Littorina kurila Middendorff, 1848 · unaccepted
Littorina kurila var. costulata Middendorff, 1851 · unaccepted
Littorina kurila var. fasciatus Middendorff, 1851 · unaccepted
Littorina kurila var. fuscus Middendorff, 1851 · unaccepted
Littorina kurila var. griseolacteus Middendorff, 1851 · unaccepted
Littorina kurila var. zonatus Middendorff, 1851 · unaccepted
Littorina sitchana [sic] · unaccepted > misspelling - incorrect subsequent spelling
Littorina sitchana kurila Middendorff, 1848 · unaccepted > junior subjective synonym
Littorina sitchana subtenebrosa Middendorff, 1848 · unaccepted > junior subjective synonym
Littorina sitchana var. castaneus Middendorff, 1849 · unaccepted
Littorina sitchana var. zonatus Middendorff, 1849 · unaccepted
Littorina sitchensis G. Nevill, 1885 · unaccepted
Littorina sitkana var. subtenebrosa Middendorff, 1848 · unaccepted > junior subjective synonym
Littorina subtenebrosa Middendorff, 1848 · unaccepted
Neritrema sitkana (R. A. Philippi, 1846) · unaccepted > junior subjective synonym
Neritrema sitkana kurila (Middendorff, 1848) · unaccepted > junior subjective synonym
For sources, see further links.
