Cycle de développement, croissance et production de Pisidium amnicum (Mollusca: Bivalvia) dans le Saint-Laurent (Québec)

Abstract

The population dynamics of Pisidium amnicum have been studied in one population of the St. Lawrence River over a 2-year period during which 19 samples were taken. The species can live up to 3 years and it is iteroparous; individuals generally attain sexual maturity after 1 year and they reproduce twice, once at 2 and once at 3 years of age. In adults, mortality is lower in winter than during the rest of the year and mortality rates are twice as high during the 1st year than during the 2nd year. Total dry weight (PT, in milligrams) is related to maximum length (L, in millimetres) according to the equation PT = 0.0283∙L3,80 and flesh dry weight (PC, in milligrams) is related to length as follows: PC = 0.007∙L3,18. The annual production to mean biomass (P/B) ratio is 1.4, the mean annual production being 1.298 mg/m2 of total dry weight and 107 mg/m2 of flesh weight. Comparing these results with those obtained for the gastropod Bithynia tentaculata in the same environment and at the same period of the year has shown that the growth of Pisidium amnicum is far less influenced by the temperature regime than that of the other species and that its production is at least 10 times lower.

Population dynamics and life cycle of Pisidium amnicum (Müller) (Bivalvia : Sphaeriidae) and Valvata piscinalis (Müller) (Gastropoda : Prosobranchia) in the Saône river, a nine-year study

“…However, only a few field experiments have been carried out to test the ecological consequences of climatic warming on freshwater macroinvertebrates (Hogg et al 1995, Hogg & Williams 1996, McKee et al 2003) and the latter is alone in taking gastropods into account. The results in this study show that the total density of 6 species (not including V. piscinalis) introduced in the microcosm increased significantly with a continuous 3°C above ambient and (9) Araujo et al 1997-2002Hinz (1976) et al (1997) (1981 (McKee et al 2003). In three Polish reservoirs heated by power plants, the abundance of two non-native species Physella acuta (Draparnaud) and Potamopyrgus antipodarum (Gray) increased during the period 1971-1991.…”

“…In Canada and Finland the cohort appears later (June-July vs April-May), the maximum number of shelled larvae/ parent is lower (18-29 vs 34-163), the life span is longer (36 vs 15 months) and the clams reach maturity later (12-13 vs 3-4 months) than in countries further south, such as Germany, France, Spain and Portugal (Danneel & Hinz 1976, Bass 1979, Holopainen 1979, Vincent et al 1981, Holopainen et al 1997, Araujo et al 1999, Sousa et al 2008. Among the Nordic populations with longer life-spans only that of the St. Lawrence river in Canada produces two cohorts.…”

“…P. amnicum is an interstitial suspension feeder (Lopez & Holopainen 1987) and V. piscinalis a detritus feeder (Fretter & Graham 1978), but it can also feed by filtration on detritus in mud (Tsikhon-Lukanina 1963). These two molluscs are generally considered as annual species (Cleland 1954, Hunter 1961, Young 1975, Danneel & Hinz 1976, Bass 1979, Holopainen 1979, Vincent et al 1981, Holopainen et al 1997, Araujo et al 1999, however the appearance of a second generation was observed in V. piscinalis in response to a considerable decrease of its population due to a dramatic decline of submersed macrophytes (Lodge & Kelly 1985). Regarding biodegradable pollution, P. amnicum is sensitive while V. piscinalis is relatively tolerant (Mouthon 1996).…”

On the reproduction of Pisidium C. Pfeiffer, 1821 (Bivalvia: Sphaeriidae) from Sąpolno (NW. Poland)

“…This conforms to the data on the populations from Germany and Great Britain (danneel & hinz 1976, Meier-Brook 1977, BaSS 1979. In Spain and France juveniles appeared already in April (araujo et al 1999, Mouthon & dauFreSne 2008, and in Canada and Finland they were released as late as in June or July (Vincent et al 1981, holopainen & hanSki 1986, rantanen et al 1998.…”

“…When the embryos are shell-covered, the pouch walls burst but the juveniles remain within the parent's body for some time and continue growing (Piechocki 1991, KorniuShin 2007. Only after they have been released, new pouches with new embryos can be formed.Among the pisids the biology of P. amnicum is the best known (e. g. odhner 1929, danneel & hinz 1976, Meier-Brook 1977, bAss 1979, holopainen 1979, Vincent et al 1981, holopainen & hanSki 1986, piechocki & dyduch-FalniowSka 1993, holopainen et al 1997, rantanen et al 1998, araujo et al 1999, Mouthon & dauFreSne 2008, piechocki & wawrzyniak-wydrowSka 2016. Comparison of observations of different populations of the species shows how widely the life cycle parameters (e.g.…”