Diets of Larval Flatwoods Salamanders, Ambystoma cingulatum, from Florida and South Carolina
Diets of Larval Flatwoods Salamanders, Ambystoma cingulatum, from Florida and South Carolina
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DOI：
10.1670/124-03n-a
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发表时间：
2004-06
期刊：
影响因子：
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通讯作者：
M. Whiles;J. Jensen;J. Palis;W. Dyer
中科院分区：
文献类型：
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作者：
M. Whiles;J. Jensen;J. Palis;W. Dyer
摘要：由于成体和幼体栖息地的丧失和改变导致种群数量下降，斑腿螈(Ambystoma Cingulatum)被列为联邦濒危物种。目前对该物种的管理计划必须包括维护适当的幼虫栖息地。然而，这个物种的大部分自然历史都鲜为人知。本研究的目的是评价环纹夜蛾幼体的食性。我们检查了从佛罗里达州和南卡罗来纳州采集的122条幼虫的胃内容物。我们识别和测量了无脊椎动物的猎物，并使用长度-质量关系估计了生物量。甲壳类是最丰富的猎物，主要是等足类(Caecidota)、两足类(Crangonx)、环足类桡足类和枝角类(主要是Simocephalus和其他达夫类)。等足类和双足类由于体型相对较大，也是胃中生物量的主要来源。与大型幼虫相比，小型扣带藻幼虫胃中支角类的数量和比例显著增加，等足类的数量和比例显著减少(P<；0.05)。与大型幼虫相比，小型幼虫在肠道中等足类生物量的数量和比例也显著降低(P<；0.05)。我们在检查的胃中发现了一种寄生线虫Hedruris siredonis，占∼的11%，这是该寄生虫的新宿主记录。我们的结果表明，幼虫主要以淡水甲壳类动物为食，特别是等足类、桡足类、枝角类和双足类。对繁殖生境中的淡水甲壳动物群落产生不利影响的管理活动，例如使用杀虫剂或引入捕食性鱼类，可能会对这种火蜥蜴的剩余种群产生不利影响。
Abstract The Flatwoods Salamander (Ambystoma cingulatum) was listed as a federally threatened species because loss and alteration of adult and larval habitats caused population declines. Current management plans for this species must include maintenance of appropriate larval habitat. However, much of the natural history of this species is poorly known. Our objective was to evaluate the diet of A. cingulatum larvae. We examined stomach contents of 122 larvae collected from Florida and South Carolina. We identified and measured invertebrate prey and estimated biomass using length-mass relationships. Crustaceans, mostly isopods (Caecidotea), amphipods (Crangonyx), cyclopoid copepods, and cladocerans (primarily Simocephalus and other daphnids) were the most abundant prey. Isopods and amphipods also dominated stomach content biomass because of their relatively large size. Stomachs of small A. cingulatum larvae had significantly higher numbers and proportions of cladocerans and smaller numbers and proportions of isopods compared to larger larvae (P < 0.05). Smaller larvae also had significantly lower amounts and proportions of isopod biomass in their guts compared to large larvae (P < 0.05). We found Hedruris siredonis, a parasitic nematode, in ∼11% of stomachs examined; this is a new host record for this parasite. Our results indicate that larvae feed primarily on freshwater crustaceans, particularly isopods, copepods, cladocerans, and amphipods. Management activities that adversely impact freshwater crustacean communities in breeding habitats, such as pesticide use or introductions of predatory fish, could adversely impact remaining populations of this salamander.