Hall John A, Larsen John H, Fitzner Richard E
Department of Zoology, Washington State University, Pullman 99164, USA.
J Morphol. 2002 May;252(2):114-30. doi: 10.1002/jmor.1094.
We provide a detailed description of the larval morphology of the Great Basin spadefoot toad (Scaphiopus intermontanus), a species with documented morphological variability in larval structures associated with feeding. We based our findings on laboratory-raised individuals fed a herbivorous diet. We characterized the morphology of the prometamorphic larva (limited to developmental stages 37 and 38) and then related our findings to the larval ecology of the species. Based on its morphology, such as slightly depressed body, dorsally positioned eyes, anteroventrally oriented oral disc, intermediate tail fin height and slightly attenuated tail tip, relative lack of ventral neuromasts (compared to Xenopus laevis), and pigmentation banding patterns, and habits, such as selection of breeding sites by adults and larval foraging behavior, S. intermontanus can be characterized best as belonging to a (lentic-) benthic guild of anuran larvae. Nevertheless, the larvae are capable of occupying a broader array of ecological niches. Because we characterized individuals raised on a herbivorous diet, our morphological descriptions apply only to the herbivorous S. intermontanus larva (and perhaps to those larvae that are dietary generalists and may feed carnivorously only infrequently). Our findings can serve as a baseline for future morphological and developmental comparisons with the carnivorous morphological variant of this species.
我们详细描述了大盆地锄足蟾（Scaphiopus intermontanus）的幼体形态，该物种在与进食相关的幼体结构上具有形态变异性记录。我们的研究结果基于以草食性食物喂养的实验室饲养个体。我们对前变态幼体（限于发育阶段37和38）的形态进行了特征描述，然后将我们的发现与该物种的幼体生态学联系起来。基于其形态，如身体略凹陷、眼睛位于背部、口盘向前腹侧定向、尾鳍高度适中且尾尖略变细、与非洲爪蟾相比腹侧神经丘相对较少以及色素带纹模式，以及习性，如成体对繁殖地点的选择和幼体觅食行为，大盆地锄足蟾最适合被归类为无尾目幼体的（静水 - ）底栖类群。然而，幼体能够占据更广泛的生态位。由于我们描述的是食用草食性食物饲养的个体，我们的形态描述仅适用于草食性的大盆地锄足蟾幼体（也许还适用于那些饮食宽泛、可能很少肉食性进食的幼体）。我们的发现可以作为该物种肉食性形态变体未来形态学和发育比较的基线。
