Having a noncoiled, limpet-like shell is a characteristic shared by numerous gastropod molluscs, including many lineages outside the true limpets (Patellogastropoda) where it has evolved convergently. The shell shape of limpet-formed gastropods has often been used as a key taxonomic character, and although studies have shown that it can vary depending on the substrate morphology, these have mostly been examples from true limpets. Over a dozen origins of limpet-form are known in Vetigastropoda, and these limpets are still generally assumed to have rather stable shell forms that are useful for taxonomy and species identification. Here, we show that the vetigastropod limpet Lepetodrilus nux (Okutani, Fujikura & Sasaki, 1993) from a deep-sea hot vent in the Okinawa Trough develop distinct shell forms when living on different substrate types. Sequences of the barcoding region of the mitochondrial cytochrome c oxidase subunit I gene among the three forms only differed by 0.31–0.63% (K2P distance) in a 637 bp alignment, in line with the differences in shell morphology being intraspecific. The extent of shell form shift seen in this species is likely the largest reported for a vetigastropod limpet and provide further evidence that such plasticity is not phylogenetically constrained but is an intrinsic part of having a limpet-like shell.

具有无线圈的，类似帽贝的壳是许多腹足纲软体动物共有的特征，包括在真正的帽贝（Patellogastropoda）以外的许多谱系，那里进化了。形成帽贝的腹足动物的壳形经常被用作关键的分类学特征，尽管研究表明它可以根据基质的形态而变化，但这些大多是真正的帽贝的例子。Vetigastropoda中有超过十二种帽贝形式的起源，这些帽贝仍被普遍认为具有相当稳定的壳形，可用于分类学和物种识别。在这里，我们显示了vetigastropod帽贝Lepetodrilus nux（Okutani，Fujikura和Sasaki，1993）来自冲绳海槽深海热口，当它们生活在不同的基质类型上时，会形成不同的壳形。三种形式中的线粒体细胞色素C氧化酶亚基I基因的条形码区域的序列在637 bp的比对中仅相差0.31-0.63％（K2P距离），这符合种内壳形态的差异。在该物种中观察到的壳形式变化的程度可能是报道的类绿象足动物中最大的，并且提供了进一步的证据表明这种可塑性不受系统发育的限制，而是具有类似壳的壳的固有部分。