Patek S N, Oakley T H
Biology Department, Duke University, Durham, North Carolina 27708, USA.
Evolution. 2003 Sep;57(9):2082-100. doi: 10.1111/j.0014-3820.2003.tb00387.x.
Communication structures vary greatly in size and can be structurally and behaviorally integrated with other systems. In structurally integrated systems, dramatic changes in size may impose trade-offs with the size of neighboring structures. In spiny lobsters (Palinuridae), there is a fivefold difference in size of the antennular plate, on which sound producing apparatus is located, such that the antennular plate reaches 38% carapace length in some sound producers (Stridentes) compared to only 4% carapace length in non-sound producing spiny lobsters (Silentes). We examined whether this major variation in antennular plate size imposes trade-offs with the adjoining antennae, specifically in the context that the signal producing structures and antennae are both used in predator defense. We recorded and analyzed lobster sounds in order to test whether size increases in the acoustic morphology were correlated with production of particular signal features. Antennal and antennular plate structures were measured across the family, including both Stridentes and Silentes. Phylogenetic comparative methods were used to test for correlated evolutionary change among the structures and signal features. We analyzed the phylogenetic relationships of the Palinuridae based on morphological characters and ribosomal DNA evidence (16S, 18S and 28S nuclear and mitochondrial ribosomal RNA gene regions). We found that the number of sound pulses was positively correlated with length of the sound producing apparatus. Opposite to the predicted trade-offs, we found that the size of the antennular plate was positively correlated with size of the surrounding antennae within Stridentes. Nevertheless, when Stridentes were compared to Silentes, the latter had relatively larger antennae for a given antennular plate size than did the sound producing taxa. These results suggest that body size does not limit size increases in acoustic structures within Stridentes, however the presence and associated constructional costs of a sound producing apparatus may impose a trade-off when taxa with and without the apparatus are compared. Alternatively, since both systems are used in predator defense, this pattern may indicate greater selection for antennal force production in Silentes, which lack the additional acoustic mode of predator defense.
通讯结构在大小上差异很大，并且在结构和行为上可以与其他系统整合。在结构整合的系统中，大小的显著变化可能会与相邻结构的大小形成权衡。在多刺龙虾（龙虾科）中，触角板的大小相差五倍，发声器官就位于触角板上，在一些发声的多刺龙虾（发声者）中，触角板长度达到头胸甲长度的38%，而在不发声的多刺龙虾（不发声者）中，触角板长度仅为头胸甲长度的4%。我们研究了触角板大小的这种主要差异是否会与相邻的触角形成权衡，特别是在信号产生结构和触角都用于防御捕食者的背景下。我们记录并分析了龙虾的声音，以测试声学形态的大小增加是否与特定信号特征的产生相关。对整个龙虾科的触角和触角板结构进行了测量，包括发声者和不发声者。系统发育比较方法用于测试结构和信号特征之间的相关进化变化。我们基于形态特征和核糖体DNA证据（16S、18S和28S核和线粒体核糖体RNA基因区域）分析了龙虾科的系统发育关系。我们发现声音脉冲的数量与发声器官的长度呈正相关。与预测的权衡相反，我们发现在发声者中，触角板的大小与周围触角的大小呈正相关。然而，当将发声者与不发声者进行比较时，对于给定的触角板大小，不发声者的触角相对比发声类群的触角更大。这些结果表明，体型大小并不限制发声者声学结构的大小增加，然而，发声器官的存在及其相关的构建成本在比较有和没有该器官的类群时可能会形成一种权衡。或者，由于这两个系统都用于防御捕食者，这种模式可能表明在缺乏额外声学防御捕食者模式的不发声者中，对触角产生力量的选择更大。
