Unraveling distributional patterns and life-history traits of a deep-water shrimp Plesionika edwardsii (Decapoda, Pandalidae) under unexploited virgin conditions: a benchmark for fisheries management

Plesionika edwardsii (J.F. Brandt in von Middendorf, 1851) is a cosmopolitan species that inhabits cold temperate and subarctic waters between 50 and 680 m. In the Azorean region, this is the second most abundant shrimp species and populations remain unexploited. To provide insights into a pristine state that can be useful for comparisons across regions and serve as a benchmark for a potential fishery in the future, we analyzed data collected during shrimp trap surveys in the Azores between 1999 and 2000. Plesionika edwardsii were caught between 100 and 600 m depth, with the biggest catches between 200 and 400 m. Sizes varied from 8.3 to 31.3 mm cephalothorax length (CL). Females were bigger and more abundant than males and predominated at depths up to 300 m. Ovigerous females were caught throughout most of the year, with a peak of abundance during the winter. The size at 50 % maturity was 25 mm CL. High variability in distributional patterns and life-history traits has been observed in our study and when compared with literature from other regions, it is difficult to distinguish which differences are potentially fishing-induced. Future studies should investigate the oceanographic processes associated with P. edwardsii ecology and commercial fisheries should be made on a precautionary basis.

Automated summary

Plesionika edwardsii is a cosmopolitan species found in cold temperate and subarctic waters, with the Azores being its second most common habitat where populations remain unexploited. Research in the area revealed that this species is most abundant between 100 and 600 m depth, with females being larger and more abundant than males, and ovigerous females mainly appearing in winter with a 25 mm size at 50% maturity. The study also highlighted high variability in distribution patterns and life-history traits, emphasizing the need for further investigation into oceanographic processes associated with this species and a precautionary approach to commercial fisheries.