二枚貝貝殼の変異と相対成長 I : 福岡市郊外津屋崎産タマキガイ属 Glycymeris 2 種について
スポンサーリンク
概要
- 論文の詳細を見る
It needs scarcely be said that a biometrical approach on the basis of sound population concept is one of the most reliable methods for the taxonomic discrimination and the consideration of phylogeny in palaeontology as well as in neontology. As a theme of the palaeontological exercise for students in the academic year 1967, we attempted to examine the variation and relative growth of several Recent bivalves on the basis of a thanatocoenosis of shells at the coast of Tsuyazaki, about 22 km north of Fukuoka City (Text-fig. 1). The result of this exercise on the left valves of two species of Glycymeris, which was confirmed again by the first author, is summarized here as the first report of this serial study. 1) The 26 individuals of Glycymeris vestita (DUNKER) and 113 individuals of Glycymeris albolineata (LISCHKE) from this locality seem to represent two interbreeding populations respectively, because the resulting frequency distribution concerning several quantitative characters appears to be normal in each species. The two species can be discriminated by the difference of the relative length of hinge plate, which is very significant according to the result of STUDENT's t-test. 2) PEARSON's coefficient of variation (V) may vary to some extent among characters even within one population. In the two species the inflation of valve (T/H) is more changeable than the elongation of shell (L/H) and relative length of hinge plate (D/L), although it may be more or less influenced also by the ontogenetical transformation. 3) The bivariate analyses between the measured parameters (L, H, T, D) in the two species resulted in the following simple allometrical equations which were gained by the regressions (fitted by least squares) from all the measured individuals (Text-figs.4-9). G. vestita : L=1.143H^<0.993> T=0.189H^<1.117> D=0.548L^<1.001> G. albolineata : L=0.982H^<1.037> T=0.247H^<1.057> D=0.627L^<1.013> It is worthy to note that the growth rate of T to H is much larger than 1 in the two species, indicating a distinct positive allometry. As to other bivariate relations the growth had better be said nearly isometrical. 4) An indistinct critical point, where the growth rate may be changed a little, seems to be shown in each double logarithmic graph between L and H and also between T and H in G. albolineata (Text-figs.7, 8). 5) In G. albolineata a distinct critical point is recognized by the double logarithmic graph which shows the relative growth between the weight of shell (W) and the volume of circumscribed cuboid (LHT)(Text-fig.10). The allometrical equation is W=0.405(LHT)^<0.982> for the smaller specimens and W=0.041(LHT)^<1.487> for the larger specimens. This fact certainly indicates that the relative thickness of test becomes larger after the beginning of the gerontic stage. Such a bivariate analysis, therefore, may be generally applicable as a useful method to determine whether or not a collected fossil population includes gerontic individuals.
- 日本貝類学会の論文
- 1968-11-30
日本貝類学会 | 論文
- 15. インドネシア スンバ島における Nautilus の漂着(平成 2 年度日本貝類学会総会研究発表)
- 神奈川県真鶴岬産の火山岩に穿孔する二枚貝類について
- 3. カワニナ類の分子生物地理学的研究(日本貝類学会平成 15 年度大会(豊橋)研究発表要旨)
- 沖永良部島以南に分布するオキナワヤマタカマイマイ類(有肺類:ナンバンマイマイ科:ニッポンマイマイ属)の再検討と再記載
- P17. シュリマイマイ種群の遺伝的分化(日本貝類学会平成19年度大会(豊橋)研究発表要旨)