Prey selection by several orb-web spiders
Project/Area Number |
04640615
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
生態学
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Research Institution | RITSUMEIKAN UNIVERSITY |
Principal Investigator |
YOSHIDA Makoto Ritsumeikan Univ. Fac.of Soi.& Engi. Assist.Professor, 理工学部, 助教授 (70121621)
|
Project Period (FY) |
1992 – 1993
|
Project Status |
Completed (Fiscal Year 1993)
|
Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
|
Keywords | Characters of the web / Capture index / Prey size / Prey items / 垂直円網 / 水平円網 / 人工網 / 餌の細成 / 利用可能な餌 / 網の特性 |
Research Abstract |
A) Several characters of spider webs were measured and following index was calculated for the webs of each species : Capture Index = Intensity of adhesiveness X Strength of spirals X Strength of radii X Number of radii * Interval between spirals Eight spider webs are divided into following three groups by the value of the capture index : 1) Capture index is very large, so the web can capture very large and heavy prey insects. Of course, small and intermediate sized prey can also be captured by the webs. The webs of Argiope bruennichi, A.amoena and Nephila clavata. 2) Capture index is very small, so the web can capture only very small and / or light prey. The webs of Tetragnatha maxillosa, T.praedonia and Leucauge magnifica. 3) The value of capture index is intermediate, so the web can small and intermaediate sized prey insects. The webs of Argiope boesenbergi and Metleucauge kompirensis. B) The webs with large capture index captured various sized prey, and very small prey were most abaundant. But, Argiope bruennichi fed larger prey selectively. The webs with small capture index captured small prey, mainly nematocerous insects and mayflies. And the webs of Metleucauge kompirensis, with intermediatecapture index, captured mainly mayflies. So, it was verified that there was the close relationship between the characteristics of the web and its prey.
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Report
(3 results)
Research Products
(9 results)