Abstract:

Aims: Xiangshan Bay is a significant fishery area in Zhejiang Province, characterized by abundant marine biodiversity. While previous studies have listed crabs (Decapoda: Branchyura) from this area, their findings often remain inconclusive, as they primarily focus on variation in macrobenthic and fishery community structure or responses to human activities. However, there is limited understanding of the species diversity and diagnostic characteristic of some rare crab species in Xiangshan Bay. Based on an extensive, long-period survey, this study aims to provide a comprehensive and scientific checklist of crabs from Xiangshan Bay. 

Methods: The study involved investigations at 40 subtidal and 10 intertidal stations, covering almost the entire Xiangshan Bay. Of these stations, 10 subtidal and 3 intertidal stations focusing on macrobenthos were surveyed in May and November (2018–2021 and 2023). Additionally, surveys targeting macrobenthos and fishery resources were conducted in November (2022–2023) and February, May, and August (2023–2024). All crabs were separated from specimens and identified using the latest taxonomic literature. 

Results: A total of 64 crab species, classified into 47 genera and 22 families, were identified. Among these, seven species were previously undocumented in Zhejiang Province: Ser mikawaensis, Rhizopa gracilipes, Shenius anomalus, Paradromia japonica, Benthopanope eucratoides, Trissoplax dentate, and Venitus latreillii. S. mikawaensis is a new record for Chinese waters, while R. gracilipes and S. anomalus are new record species for the East China sea. The diagnostic characteristics of these newly recorded species were described and illustrated. 

Conclusion: This study reports significantly more crab species in Xiangshan Bay compared to previous research. It provides the first systematic checklist of crabs in the region, alongside detailed descriptions of the newly recorded species. These findings provide valuable reference material for conserving crab diversity and improving the taxonomic identification of crabs in Xiangshan Bay.

Key words: Xiangshan Bay, Ser mikawaensis, Rhizopa gracilipes, Shenius anomalus, newly records species