Formwachstumsversuche an Sphaerium corneum

Thiel, Max Egon

doi:10.1007/bf02079286

Cited by 6 publications

(3 citation statements)

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“…W Wilder (1924). finds a similar alternation, of periods of filling out and periods of rapid length-growth with drop in the body-build index, in the larval growth of the salamander Eurycea bilineata, and the same phenomenon is stressed for human children by various authors, notably Bean (1924),Harris (1931 A and b), and with all the apparatus of biometrical method by Berkson (1929)1 Thiel (1926),. as the result of careful measurements on the skull of the bivalve mollusc Sphaerium, finds an alternation of periods of increased intensity of growth in height and decreased intensity of growth in breadth with periods where the reverse relation holds.…”

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confidence: 65%

“…It is by this means that he would account for the well-known fact of the increase in the abdomen-width ( Thiel (1926) upon the Lamellibranch mollusc Sphaerium. He shows that in clean water with high oxygen content, the form of the shell becomes more rounded than in the dirty water of its normal habitat. This, however, PROBLEMS OF RELATIVE GROWTH appears to be mainly or solely a mechanical effect due to an alteration in the direction rather than the amount of growth of the mantle-edge, and to be determined by an increase in the number of embryos contained in the gills.…”

Section: The Influence Of External Conditionsmentioning

confidence: 99%

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Problems of relative growth, by Sir Julian S. Huxley...With 105 illustrations.

Huxley¹

1932

167

227

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mentioning

confidence: 65%

Section: The Influence Of External Conditionsmentioning

confidence: 99%

Problems of relative growth, by Sir Julian S. Huxley...With 105 illustrations.

Huxley¹

1932

167

227

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“…2). Unfortunately, without more detailed morphological studies one cannot infer from this relationship alone to what extent space in the mantle cavity is limiting maximum litter size (see discussion in Thiel 1926, Meier-Brook 1970. Hoiopainen and Kuiper 1982, Mackie and Flippance 1983.…”

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confidence: 99%

Life history variation in Pisidium (Bivalvia: Pisidiidae)

Holopainen

Hanski

1986

Ecography

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Life history variation in Pisidium (Bivalvia: Pisidiidae) fsmo J. Holopainen and Ilkka Hanski Hulupainen, I. J. und Hanski, I. 1986. Life history variation in Pisidium (Bivalvia: Pisidiidae). -Holarct. Ecol. 9: 85-98.Intraspecific variation in the maximum shell length of Pisidium is small in comparison with variation in the life span of the clams, from 4 mo to 4 yr. The use of shell length as a measure of size is complicated by large intraspecific variation in the weightlength relationship, a possible reflection of resource availability on the weight of the soft parts. Maximum embryo length is relatively constant (1 mm) in the majority of species but litter size is variable (1 to 40), generally increasing with parent size. The time of egg-laying is determined by the size of the clam, season, and previous episode of reproduction, while the timing of the release of embryos, depending also on embryonic growth rale, is additionally affected by temperature and oxygen conditions. In brief, the maximum adult and embryo lengths are relatively conservative traits while growth rates vary by an order of magnitude. Reproductive effort, when measured by the ratio of litter weight to parent weight, may increase or decrease with parent length and age. Both semelparous and iteroparous populations are known in several species. We suggest that if maximum adult length can be reached by the first reproductive season (in a favourable environment) the population is semelparous, otherwise (in an unfavourable environment) the population is iteroparous. Gravid elams in semelparous populations continue to grow, and thus assimilation cannot be meaningfully partitioned into reproduction, somalic growth and maintenance. Along a depth gradient from 8 lo 65 m, maximum and mature shell lengths, embryo length and litter size varies significantly in Pisidium conventus subpopulations not distinguishable electrophoretically. Large clams in deep water produce large embryos but small litters, which is contrary to the general trend of increasing litter size with parent length. Low food availability that decreases juvenile growth rate may restrict litter size in this case.

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Zur Hebung der Flußperlmuschelzucht und zur Frage der natürlichen Entstehung der Perlen

Thiel¹

1931

Intl Review of Hydrobiology

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Formwachstumsversuche an Sphaerium corneum

Cited by 6 publications

References 2 publications

Problems of relative growth, by Sir Julian S. Huxley...With 105 illustrations.

Problems of relative growth, by Sir Julian S. Huxley...With 105 illustrations.

Life history variation in Pisidium (Bivalvia: Pisidiidae)

Zur Hebung der Flußperlmuschelzucht und zur Frage der natürlichen Entstehung der Perlen

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