Search for: All records

Abstract Animals have myriad adaptations to help them hunt and feed in the most efficient and effective manner. One mysterious behavior related to hunting and feeding is the posterior toe tapping behavior of some frogs. Biologists and hobbyists alike have long noticed this behavior, but there is little empirical data to explain its causes and consequences. To test the hypothesis that tapping is related to feeding and modulated by environmental context, we conducted a series of related experiments in the Dyeing poison frog,Dendrobates tinctorius. We first confirmed that tap rate was higher during feeding as has been observed in other species. Interestingly, this effect was heightened in the presence of a conspecific. We next asked whether frogs tapped less under conditions when prey were visible, but inaccessible. Finally, we asked whetherD. tinctoriusadjusted tap rate based on substrate characteristics and whether prey capture success was higher when tapping. In addition to confirming an association between tapping and feeding, our work demonstrates modulation of toe tapping based on social context, prey accessibility, and substrate characteristics. Based on our findings, we suggest that tapping could act to induce prey movement and thereby facilitate prey detection and capture by frogs. 

Abstract While vertebrate immune systems are appreciated for their complexity and adaptability, invertebrate immunity is often considered to be less complex. However, immune responses in many invertebrates likely involve sophisticated processes. Interactions between the crustacean hostDaphnia dentiferaand its fungal pathogenMetschnikowia bicuspidataprovide an excellent model for exploring the mechanisms underlying crustacean immunity. To explore the genomic basis of immunity inDaphnia, we used RNA‐sequencing technology to quantify differential gene expression between individuals of a single host genotype exposed or unexposed toM. bicuspidataover 24 h. Transcriptomic analyses showed that the number of differentially expressed genes between the control (unexposed) and experimental (exposed) groups increased over time. Gene ontology enrichment analysis revealed that differentially expressed genes were enriched for immune‐related molecules and processes, such as cuticle development, prostaglandin, and defense response processes. Our findings provide a suite of immunologically relevant genes and suggest the presence of a rapidly upregulated immune response involving the cuticle inDaphnia. Studies involving gene expression responses to pathogen exposure shine a light on the processes occurring during the course of infection. By leveraging knowledge on the genetic basis for immunity, immune mechanisms can be more thoroughly understood to refine our understanding of disease spread within invertebrate populations.