Population structure of the stone crab Xantho poressa (Olivi, 1972) in a human restricted access area
| Autor: | Navarro-Ojeda, Nebis, Cuesta, José A., González-Ortegón, Enrique |
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| Přispěvatelé: | Universidad Simón Bolívar (Venezuela), Asociación Universitaria Iberoamericana de Postgrado (España) |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | The stone crab Xantho poressa, is an intertidal species that inhabits the Gulf of Cadiz (GoC), the Mediterranean Sea, the Black Sea and the Canary Islands. In the GoC, this crab inhabits hiding under boulders of rocky beaches, but little information exists regarding its population. The main objective of this research was to analyse the population structure of X. poressa in an intertidal rocky shore beach with restricted access (Torregorda beach, SW Spain). A total of 190 boulders were analysed monthly from March 2019 and February 2020. In the field, individuals of X. poressa were sexed and crab size was measured using the carapace width (CW). Accompanying fauna and boulder information (location, size, and weight) were also collected. A total of 1386 individuals were analysed during the studied year (667 females, 411 males, 269 juveniles and 39 undefined individuals). The overall sex ratio differed from the 1:1 assumption on each month (except in December 2019), and seasonally. The size of adult males and females showed significant difference (p < 0.05) and varied from 11.54 to 38.19 mm CW (20.17 ± 5.08 mm), and 10.12 to 28.08 mm CW (16.22 ± 3.39 mm) respectively. The modal class for females was 14 – 16 mm CW and 20 – 22 mm CW for males. Multivariate analysis showed that X. poressa distribution in the intertidal shore seems to be mainly determined by the weight of the boulder. The frequent coexistence of a male and various females under a boulder should explain the female-biased sex ratio observed in this study which was previously suggested in another beach of the GoC. We thank the Spanish Ministry of Defence, INTA, A. Moreno, D. Roque, Universidad Simón Bolívar and the AUIP for their support in this research. |
| Databáze: | OpenAIRE |
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