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Physa acuta Draparnaud, 1805
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Species name:
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Physa acuta Draparnaud, 1805
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Taxon name:
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Physa acuta Draparnaud, 1805
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Originally described in:
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Draparnaud, J.-P.-R. [1805]. Histoire naturelle des mollusques terrestres et fluviatiles de la France. Ouvrage posthume. Avec XIII planches. - pp. [1-9], j-viij [= 1-8], 1-134, [Pl. 1-13]. Paris, Montpellier. (Plassan, Renaud).
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Distribution:
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Worldwide, originally from either SW Europe or North America (in Switzerland since the 1840s)
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Diagnosis:
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Shell light horny yellowish, sometimes slightly transparent, pale shiny, apex pointed, 4-5 not very convex whorls without deep suture, aperture 3/4 of shell height, columella and apertural lip in fully grown shells white.
Aperture higher than in Ph. heterostropha.
Animal blackish or dark grey with violet hue, mantle with golden spots which are visible below the shell, tentacles greyish and almost transparent with small blackish eyes, foot lighter with fine black pigment spots.
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Size:
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8-16 x 5-9 mm
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Biology:
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Warm standing and slowly moving waters, at margins of lakes, tolerates eutrophic conditions. In coastlands of central Portugal very frequently in waters supplying rice crops. Feeds mainly on detritus and green algae. In Switzerland in up to 800 m altitude, but not frequent except in warm springs, in Germany in lowlands.
Oval eggs (0.8-1 x 0.5 mm) are laid in elongate packages (4-20 x 2.5-5 mm) containing 20-400 eggs (usually below 50), juveniles hatch after 20 days in temperate France (15 days in S Europe), initial size 0.5-0.7 mm, maturity is reached after 17-18 months. Two generations per year.
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Threatened:
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In many regions the most frequent freshwater mollusc in Spain.
Vulnerable in Switzerland.
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Family:
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Physidae
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Higher group:
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Gastropoda
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Comments:
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Google (02.2011, Germany) general search: Physa 37300, Physella 13300, Haitia 400; Google Scholar: Physa 1700, Physella 435, Haitia 20.
References: Moquin-Tandon 1855: 452, Germain 1931: 510, Nobre 1941: 207, Falkner 1990: 130, Manganelli et al. 1995: 10, 35, Pujante Mora et al. 1998, Turner et al. 1998: 113, Glöer 2002: 238, Pérez-Quintero et al. 2004, Welter-Schultes 2012: 56 (range map Europe).
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