Ionian Sea, Italy – Researchers have documented the rapid appearance of the Indo-Pacific crab Gonioinfradens giardi in the Ionian Sea, providing early evidence that the species may be establishing populations in the central Mediterranean.

The first confirmed record in Italy was a single specimen collected at Portopalo di Capo Passero in November 2025. Between November 2025 and January 2026, scientists observed 11 additional crabs, suggesting the species is moving beyond sporadic sightings.

“Our findings suggest that Gonioinfradens giardi is transitioning from occasional records to a more consistent presence in the central Mediterranean. This raises important questions about its potential ecological role and interactions with native species,” explained Francesco Tiralongo, lead author of the study.

The research combined recent records with field observations collected in collaboration with local fishers using artisanal fishing gear. The dozen individuals captured within two months mark the westernmost presence of the species in the Mediterranean and indicate favorable conditions for its survival.

“The rapid emergence of this species highlights how dynamic and responsive Mediterranean ecosystems are to ongoing environmental changes,” said Alberto Felici, co-author of the study. “Documenting these early phases of establishment is crucial for understanding future ecological scenarios and supporting informed management decisions.”

The spread of non-native crabs like G. giardi could affect native species and local fisheries. While the long-term impacts remain uncertain, its quick expansion reflects ongoing changes in Mediterranean marine biodiversity.

Tiralongo added that continuous monitoring, including contributions from fishers and citizen scientists, will be essential to track these developments and support adaptive management.

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