Massive Stranding of Macroramphosus gracilis (Lowe 1839) in the Strait of Messina (Central Mediterranean Sea): Somatic Features of Different Post-Larval Development Stages

The Strait of Messina (Central Mediterranean Sea) has always been known for the stranding of marine organisms, especially during the spring. We came across an extraordinary event of mass stranding in April 2025, with 453 specimens of Macroramphosus sp. found through a single night. A total of 571 post-larvae and juvenile individuals stranded between February and May 2025 were examined for this study. Clear morphological differences related to the size, especially in post-larvae were highlighted. The relationship between Body Length (BL) and other morphometric measurements, such as Dorsal Spine Length (DSL), Snout Length (SNL), and Body Height (BH) were studied with the aim of identifying without any doubt the species Macroramphosus gracilis. A slightly negative allometric relationship between length and weight shows that it grows faster in length and slower in weight. This study aims to improve the state of knowledge on slender snipefish M. gracilis, and particularly on the somatic features of different post-larval development stages. All these morphological changes could give us a hint at the ecological adaptation to the habit shift related to the development. Larvae and post-larvae of M. gracilis under 36 mm SL appear to be more linked to the epipelagic/hyponeustonic habitat, while adult individuals seem to prefer benthopelagic habits. Our results support the hypothesis that the Strait of Messina represents an exclusive and crucial zone for the reproduction and growth of M. gracilis.