Life History Parameters and Fishing Aspects of the Alien Nimble Spray Crab Percnon gibbesi in a Native Area of the Central-East Atlantic

Simple Summary We investigated the status and population structure of Percnon gibbesi in three areas of the island of Gran Canaria (Canary Islands, Central-East Atlantic) between July 2020 and December 2021. A total of 999 individuals were captured. Monthly sampling allowed us to establish the reproductive season according to the presence of ovigerous females. The methodology and number of individuals analysed were suitable for establishing the length-weight relationships and the life history parameters via modal progression analysis. The analysis of the catches per unit effort (CPUE) revealed the abundance of Percnon gibbesi in the three areas and seems to not conform with the catch quotas established in the Canary Islands Fisheries Law. Percnon gibbesi is a native crab species characteristic of intertidal and subtidal zones of the Atlantic coast of the European Macaronesian archipelagos (Azores, Madeira, and Canary Islands), and probably also in the neighbouring rocky coasts of northwest Africa. P. gibbesi is considered an invasive alien species in almost all of the Mediterranean, with expanding populations from Spain to Turkey, including Libya; However, its biology and ecology are highly unknown, despite all its range of distribution. In the intertidal zones of Gran Canaria Island, this crab, in the intertidal zones of Gran Canaria Island, shows a carapace length range between 4.1 and 22.7 mm (4.1-22.7 in males and 5.7-22.3 in females), where females showed higher weights and lengths than males on average; However, males predominated in all samples, with a sex ratio of 1:0.57. The L-infinity for this crab was estimated to be 27 +/- 3 mm (23 +/- 4 mm for females and 25 +/- 4 mm for males). The growth coefficient (K) was 0.24 year(-1), the total mortality (Z) was Z = 1.71 year(-1), and the natural mortality (M) was 0.47 year(.)(-1) Although females grow faster than males, males are more abundant in the larger length classes. Although the presence of ovigerous females indicated that reproduction takes place twice a year, from March to April and from August to September, the number of cohorts detected by the modal progression analysis showed that reproduction takes place all year.

Automated summary

This study investigated the status and population characteristics of Percnon gibbesi in three areas of Gran Canaria Island from July 2020 to December 2021. With a sample size of 999 individuals, the reproductive season and length-weight relationships were established. CPEU analysis revealed that the abundance of Percnon gibbesi in the three areas did not conform to the catch quotas set by the Canary Islands Fisheries Law.