Literaturdatenbank
Literaturdatenbank |
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Lindeman, P. V. (2005). Aspects of the life history of the texas map turtle (graptemys versa). American Midland Naturalist, 153, 378–388.
Added by: Admin (14 Aug 2008 20:31:53 UTC) |
| Resource type: Journal Article BibTeX citation key: Lindeman2005 View all bibliographic details  |
Categories: General Keywords: Emydidae, Graptemys, Graptemys versa, Habitat = habitat, Nordamerika = North America, Pseudemys, Pseudemys texana, Schildkröten = turtles + tortoises Creators: Lindeman Collection: American Midland Naturalist |
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| Abstract |
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The Texas map turtle (Graptemys versa) is endemic to the Colorado River drainage in southcentral Texas. A study of its life history was undertaken using data collected in 1998–2000 from a population in the South Llano River, southernmost tributary of the Colorado drainage, and data from museum specimens that had been collected from the South Llano River in 1949. Compared to congeners, G. versa is a small-bodied species. Its small body size is, predictably, linked to relatively small clutch size, small egg size, rapid growth toward asymptotic size and early maturation. As many as four clutches may be laid during an active season, although the effects of follicular atresia on clutch frequency are not known. Both clutch size and egg width were positively correlated with female body size, with the former relationship having a log-log slope significantly less than the expected value of 3, probably due to the latter relationship. Analyses were consistent with the hypothesis of anatomical constraint on egg size, with at least smaller females laying eggs that are of less than optimal size. No differences were found in body size or clutch size between 1949 and 1998–2000 despite a large-scale change in diet associated with invasion of the river by Asian clams (Corbicula sp.). However, body size is substantially reduced in the South Llano River compared to other sections of the Colorado drainage, a finding mimicked by at least one other turtle species in the drainage, Pseudemys texana.
Added by: Admin |