"This study documents direct evidence of nematode predation in the free living marine nematode Synonchiella spiculora recorded in the intertidal of Santa Clara beach in the Upper Gulf of California, Mexico. The heavily armoured buccal cavity that allows S. spiculora to break larger particles and ingest other organisms is characteristic of nematodes categorized as predators and omnivores. The inferred feeding behaviour of S. spiculora and other Selachinematidae suggests that engulfing whole and relatively large prey items may be common in this group. Synonchiella spiculora could be classified in the guild of ‘predators’ sensu Jensen (1987) and Moens & Vincx (1997). Nevertheless, more direct observations are required to ‘ground truth’ inferences based on their morphological variation and to better understand their feeding ecology."