Highlighting Potential Physical and Chemical Cues Involved in Conspecific Recognition System in a Predator Nematode, Seinura caverna.

This article investigates the conspecific recognition system of the predatory nematode Seinura caverna, focusing on how it distinguishes conspecifics and closely related species to avoid cannibalism. Predation assays showed that S. caverna kills heterospecific prey nematodes but avoids killing conspecifics and the related predator Ektaphelenchoides spondylis, which share a similar type III internal cuticle ultrastructure. Behavioral observations and chemotaxis assays suggest that S. caverna employs a hierarchical recognition system combining chemical cues—specifically, water-soluble compounds that repel conspecifics—and physical cues related to cuticle structure to mediate predation decisions. These findings provide insights into the evolutionary adaptations of predatory nematodes and highlight the potential role of cuticle ultrastructure and chemical signaling in species-specific recognition.