Schoff Patrick K, Johnson Catherine M, Schotthoefer Anna M, Murphy Joseph E, Lieske Camilla, Cole Rebecca A, Johnson Lucinda B, Beasley Val R
Center for Water and the Environment, Natural Resources Research Institute, University of Minnesota-Duluth, 5013 Miller Trunk Hwy, Duluth, Minnesota 55811-1442, USA.
J Wildl Dis. 2003 Jul;39(3):510-21. doi: 10.7589/0090-3558-39.3.510.
Skeletal malformation rates for several frog species were determined in a set of randomly selected wetlands in the north-central USA over three consecutive years. In 1998, 62 sites yielded 389 metamorphic frogs, nine (2.3%) of which had skeletal or eye malformations. A subset of the original sites was surveyed in the following 2 yr. In 1999, 1,085 metamorphic frogs were collected from 36 sites and 17 (1.6%) had skeletal or eye malformations, while in 2000, examination of 1,131 metamorphs yielded 16 (1.4%) with skeletal or eye malformations. Hindlimb malformations predominated in all three years, but other abnormalities, involving forelimb, eye, and pelvis were also found. Northern leopard frogs (Rana pipiens) constituted the majority of collected metamorphs as well as most of the malformed specimens. However, malformations were also noted in mink frogs (R. septentrionalis), wood frogs (R. sylvatica), and gray tree frogs (Hyla spp.). The malformed specimens were found in clustered sites in all three years but the cluster locations were not the same in any year. The malformation rates reported here are higher than the 0.3% rate determined for metamorphic frogs collected from similar sites in Minnesota in the 1960s, and thus, appear to represent an elevation of an earlier baseline malformation rate.
连续三年，在美国中北部一组随机选取的湿地中，测定了几种蛙类的骨骼畸形率。1998年，62个地点产出了389只变态蛙，其中9只（2.3%）有骨骼或眼部畸形。在接下来的两年里，对最初地点的一个子集进行了调查。1999年，从36个地点收集了1085只变态蛙，其中17只（1.6%）有骨骼或眼部畸形，而在2000年，检查1131只变态蛙后发现16只（1.4%）有骨骼或眼部畸形。后肢畸形在所有三年中都占主导地位，但也发现了涉及前肢、眼睛和骨盆的其他异常情况。北方豹蛙（Rana pipiens）构成了所收集变态蛙的大多数，以及大多数畸形标本。然而，在貂蛙（R. septentrionalis）、林蛙（R. sylvatica）和灰树蛙（Hyla spp.）中也注意到了畸形情况。在所有三年中，畸形标本都出现在聚集的地点，但任何一年的聚集地点都不一样。这里报告的畸形率高于20世纪60年代在明尼苏达州从类似地点收集的变态蛙所确定的0.3%的比率，因此，似乎代表了早期基线畸形率的上升。
