Reproductive features of the invasive crab Cronius ruber (Brachyura, Portunidae) on the Canary Islands (central eastern Atlantic), Spain

Abstract

The main features of the life cycle and ecology of the invasive species Cronius ruber in both its native range and invaded areas are unknown. Therefore, the reproductive traits of this invasive allochthonous species were studied in the Canary Islands, including sex structure, maturity, fecundity, and egg development. Females were more abundant than males, mainly in the size range between 25 and 80 mm CW. Only males were observed in size classes above 80 mm CW. Reproduction of C. ruber is continuous throughout the year, with a new oviposition immediately after the end of the egg incubation period. This process can be repeated in females up to six times, without re-mating, due to the sperm stored by females in the spermathecae. Sexual maturity was estimated at a similar size in both sexes, corresponding to 57–59 % of their maximum observed size. Egg development appeared to be completely synchronous, with a development period lasting slightly less than 1 month. The mean fecundity was 657,282 eggs, with a maximum observed fecundity of 988,509 eggs. This species shows a high reproductive potential, characteristic of invasive species.