Abstract:
Boreal chorus frogs (Pseudacris maculata Agassiz 1850) are a widespread amphibian in North America, but several populations are in decline. Specifically, we are developing captive breeding and reintroduction methods for the Great Lakes/St. Lawrence-Canadian Shield population. Here we present the effects of tadpole density, food variety, and addition of supplemental minerals to rearing water on the growth, development, and survival during the larval and metamorph/juvenile stages. We conducted two experiments using a factorial design. We found that low tadpole density (1 vs. 2 tadpoles/L) and high food variety (five food items vs. three food items) significantly increased tadpole body length and Gosner stage after 2 weeks (p < .001), increased survival to metamorphosis (p < .001), decreased time to metamorphosis (p < .001), and increased weight after metamorphosis (p < .001). On average, tadpoles in the high density/low food treatment, compared to the low density/high food, were 25% smaller after 2 weeks, had 3.9× lower survival to metamorphosis, took 1.25× longer to reach metamorphosis, and weighed 1.5× less after metamorphosis. In contrast, neither density (0.5 vs. 1 tadpole/L) nor mineral supplemented water affected growth and development, but tadpole survival was higher at 1 tadpole/L. Our findings demonstrate the feasibility of rearing boreal chorus frogs in captivity and provide guidelines for rearing this and similar species in a laboratory environment.
摘要:
北方合唱青蛙(PseudacrismaculataAgassiz1850)是北美普遍存在的两栖动物,但是一些人口正在下降。具体来说,我们正在为五大湖/圣劳伦斯-加拿大盾牌种群开发圈养繁殖和重新引入方法。在这里,我们介绍t密度的影响,食物品种,并在生长的育水中添加补充矿物质,发展,以及幼虫和变形/幼体阶段的生存。我们使用阶乘设计进行了两个实验。我们发现,低t密度(1vs.2t/L)和高食物种类(五种食物与三种食物)在2周后显着增加t体长和Gosner阶段(p<.001),变态存活率增加(p<.001),变态时间缩短(p<.001),变态后体重增加(p<.001)。平均而言,t在高密度/低食物处理中,与低密度/高食物相比,两周后缩小了25%,变态存活率低3.9倍,需要1.25倍的时间才能达到变态,变态后体重减少1.5×。相比之下,两者都没有密度(0.5vs.1t/L)也没有矿物质补充的水影响生长发育,但是,在1t/L时,t的存活率更高。我们的发现证明了在圈养中饲养北方合唱青蛙的可行性,并为在实验室环境中饲养该物种和类似物种提供了指导。