Life beneath the sand: batoid predation on neonate and juvenile angelsharks (Squatina squatina)

Abstract Understanding natural mortality during early life stages is essential for the conservation of threatened elasmobranchs, yet direct evidence of predator–prey interactions involving neonate and juvenile sharks remains scarce. The critically endangered angelshark Squatina squatina relies on shallow coastal nursery areas during its earliest life stages. Identifying the sources of natural mortality within these areas is therefore particularly relevant for conservation planning. Here, we document opportunistic evidence of batoid predation on neonate and juvenile S. squatina in the Canary Islands based on validated records collected through a coordinated citizen science monitoring network between 2020 and 2025. Six independent predation events were recorded across multiple islands, involving three batoid species: the brown stingray Bathytoshia lata , the spiny butterfly ray Gymnura altavela , and the white skate Rostroraja alba . Previous dietary studies have documented elasmobranch prey in R. alba , although predation on S. squatina has not previously been reported. All interactions occurred in shallow sandy habitats (1–12 m depth) and involved individuals corresponding to neonate and juvenile S. squatina . These events were identified within a broader dataset comprising more than 4000 observations of batoids and S. squatina , highlighting the value of sustained observational effort for documenting rarely observed ecological interactions. Although the opportunistic nature of this dataset prevents estimation of predation frequency or population-level effects, the documentation of multiple independent events indicates that batoid predation likely represents a genuine, though poorly quantified, component of early life-stage mortality for S. squatina . This study provides the first records of batoid predation on early life stages of S. squatina in the Canary Islands and highlights the value of citizen science for documenting rare ecological interactions relevant to ecosystem-based conservation.