Zur biologie unserer süsswasser-muscheln

Thiel, Max Egon

doi:10.1007/bf00408265

Cited by 5 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, some of the material might have been ingested a few days earlier when water temperatures were slightly higher. Thiel (1928) concluded that three species of Sphaerium did not grow when water temperatures fell below 8-9°C, implying that they were not feeding heavily at these temperatures.…”

Section: Discussionmentioning

confidence: 99%

Phytoplankton Ingestion by the Fingernail Clam, Sphaerium Transversum (Say), in Pool 19, Mississippi River

Gale¹,

Lowe²

1971

Ecology

View full text Add to dashboard Cite

In Pool 19 of the Mississippi River, the fingernail clam, Sphaerium transversum, appears to feed non—selectively on phytoplankton, although green algae were in higher percentages in guts than in plankton samples. Diatoms were of paramount importance in clam guts and water samples during most sampling periods, especially from December to April when mean monthly water temperatures were less than 4 degrees C. Ingestion by clams was heaviest in spring, early summer, and fall. Clams appeared to stop ingesting when water temperatures fell to about 2—4 degrees C. In February and March, 80—90% of the clams had ceased ingesting. Ingestion did not cease simultaneously in all clams. Throughout the year some contained little or no phytoplankton. Much of the phytoplankton in the gut near the anus appeared completely undigested. Phytoplankton diversity (d) in clam guts and in water was high in July and August and low in February and March. A maximum of 33 phytoplankton genera occurred in clams in August; 38 genera were present in water samples in July and August. Concentrations of over 50,000 plankters/ml (primarily Stephanodiscus hantzschii) occurred in March 1968; minimum concentrations occurred in July.

show abstract

Section: Discussionmentioning

confidence: 99%

Phytoplankton Ingestion by the Fingernail Clam, Sphaerium Transversum (Say), in Pool 19, Mississippi River

Gale¹,

Lowe²

1971

Ecology

View full text Add to dashboard Cite

show abstract

“…Species of Sphaerium in perennial habitats similarly only live for one year, e.g. S. corneum (Thiel, 1928;Alimov, 19671, S. solidum (Thiel, 1928), S. striatinum (Foster, 1932) and S. fabale (Mackie, 1979), though S. rivicola and S. simile have been reported to live for longer (Thiel, 1928;Avolizi, 1976). If the concept of r-and K-strategies breaks down with regard to pisidiid life history strategies, a second theory (Stearns, 1976(Stearns, ,1977 suggests that if variations in juvenile mortality are greater than adult mortality, a mix of the life history traits expected from r-and K-selection will occur.…”

Section: Discussionmentioning

confidence: 99%

The population dynamics, reproductive strategy and life history tactics of Musculium lacusfre (Bivalvia: Pisidiidae) in Hong Kong

Morton

1985

Journal of Zoology

View full text Add to dashboard Cite

With 1 plate and 9 figures in the text)Hitherto uninvestigated in Hong Kong are the population dynamics, reproductive strategies and life history tactics of the Pisidiidae of which three species are known to occur locally. This study is of Musculium lacustre inhabiting a drainage ditch of the Lam Tsuen River in the New Territories of Hong Kong and extended over 15 months during 1983-84.In Hong Kong, M. lacustre is a protandric, simultaneous hermaphrodite that matures at a length of 2 mm; the majority of each generation is, however, not mature until a length of between 4-6 mm is attained. Fertilized eggs are brooded in the inner demibranchs until they reach a length of 1.5 mm when they are released as post-foetal larvae. Musculium lacustre is univoltine. Reproduction occurs twice a year but, since M . lacustve is semelparous, the population contains, at any one time, two overstepping generations. Thus, a spring generation is recruited and grows rapidly to generate a second, smaller, autumn generation. This in turn grows rapidly and matures to produce the spring generation of the succeeding year. Adult mortality occurs in late summer and winter. A few of the late-born spring generation may overwinter to contribute to the spring generation of the succeeding year. This is not so with the autumn generation.Such sexual and life history tactics can be related to the climate and hydrology of Hong Kong and its freshwater habitats. Reproduction takes place in spring and autumn when temperatures are moderate. Mortality is high in summer and winter when the habitat is either, respectively, hot and flushed out by summer rains or cold and dry. As M . larustre is able to overwinter but not aestivate at these latitudes (22' N), it is postulated that this holarctic species is approaching the southern limit of its asiatic range. Musculium larustre is compared with the other bivalves inhabiting fresh and brackish-water habitats in southern China.

show abstract

“…The cause of death is not certain. Thiel (1928) reported that S^. corneum did not reach maximum size in areas that were "overpopulated," At stations 6, 8, and 14 clams of size class 6 were absent during almost all sampling periods.…”

Section: Resultsmentioning

confidence: 95%

Bottom fauna of Pool 19, Mississippi River with emphasis on the life history of the fingernail clam, Sphaerium transversum

Gale

View full text Add to dashboard Cite

This study was begun in 1966 as the first of a two phase investigation to determine dredging effects on fauna of Pool 19 of the Mississippi River. Monthly, from June to December, 1967, four 7.62 cm core-samples were taken at seven stations. The molluscan fauna included 13 species of gastropods, 7 species of sphaeriids, and 20 species of unionids. Sphaerium transversum made up over 80 per cent of the total organisms 2 at all stations, with a mean of about 40,000/m and a maximum 2 of over 100,000/m. Of the insects, Hexaqenia spp., because of its size, may be most important as fish and duck food. Leeches, Glossiphonia complanata. Helobdel1 a stagnai is and Erpobdel1 a punctata were abundant. Standing crops of benthos ranged up to 11,000 kg/ha in summer, a high biomass compared 2 to other areas. Total organisms/m were maximum in fall. The life history of S^. transversum was emphasized due to its abundance, importance to ducks, and lack of life history data. In the laboratory, 2-transversum grew from birth to maturity in 33 days or less, increasing in weight about 125 fold. Some clams of similar age failed to grow initially and became calyculate (capped) when growth occurred. In the river, calyculism was associated with season of birth. The clams became proportionately lower and wider as length increased. In areas with firm substrates and swift currents, clams were slightly more fusiform than in areas with soft

show abstract

Zur biologie unserer süsswasser-muscheln

Cited by 5 publications

References 7 publications

Phytoplankton Ingestion by the Fingernail Clam, Sphaerium Transversum (Say), in Pool 19, Mississippi River

Phytoplankton Ingestion by the Fingernail Clam, Sphaerium Transversum (Say), in Pool 19, Mississippi River

The population dynamics, reproductive strategy and life history tactics of Musculium lacusfre (Bivalvia: Pisidiidae) in Hong Kong

Bottom fauna of Pool 19, Mississippi River with emphasis on the life history of the fingernail clam, Sphaerium transversum

Contact Info

Product

Resources

About