First stress-induced parturition events of spinetail devil rays (Mobula mobular) recorded in the western mediterranean sea

Abstract

Sightings can provide valuable insights into lesser-known and endangered species by providing significant information regarding specific biological aspects. This study reports two unusual occurrences of spinetail devil ray (Mobula mobular) parturition events. The first event occurred in Calafell, Tarragona, where a stranded female gave birth to a pup of unidentified sex with an estimated disc width (DW) of 129.83 ± 2.14 cm. The second event took place in Palamós, Girona, where an incidentally captured female gave birth to a stillborn male pup of 150 cm DW. These two rare events, potentially induced by stressors such as stranding and incidental capture, respectively, are the first to be documented in the Spanish coast of the western Mediterranean Sea, suggesting that this region may be important for pelagic species such as the spinetail devil ray. These two occurrences may also indicate that this species may use certain areas of this region as breeding grounds.