Abstract From January to June 2021, mark-recapture and biometric data were collected from a population of blue crab, Cardisoma crassum Smith, 1870, from Ponuga, in Veraguas, Panama. Recapture histories of 163 crabs indicate strong burrow fidelity. During the dry season (January-March) burrow fidelity was 73.2 %, while in the rainy season (April-June) it was 50.7 %. Population was estimated at 2,569 crabs in 10.93-ha with a density of 0.024 ind. m-2. Cephalothorax width averaged 63.62 ± 6.37 mm for males (50.95-78.01 mm, N = 83) and 61.90 ± 5.47 mm for females (53.21-77.78 mm, N = 80). Blue crab reproductive season was traditionally known to take place just during the rainy season. Here, we report ovigerous females in February and March (dry season), suggesting reproduction may occur throughout the year in Panama. This is the first report of burrow fidelity and continuous biometry measurements in natural conditions for C. crassum. Burrow fidelity seems to be closely related to abiotic factors and is different between dry and rainy seasons.

Abstract Alien species are organisms introduced into an area outside of their natural range and are considered a major cause of biodiversity loss in the marine environment. The aim of this work is to report on the alien crustacean species observed in Ecuador. A bibliographic review was conducted using a digital search in the scientific literature. A total of ten alien species of crustaceans, representing eight genera in seven families, were encountered in Ecuador. The only crab, Cardisoma crassum Smith, 1870, was observed in the Galapagos Islands. The other species include barnacles, crayfishes, and freshwater prawns. Native ranges of the alien crustaceans include the Indo-Pacific region, North America, Asia, and Australia. Major introduction pathways are aquaculture and transport by ship. Procambarus alleni (Faxon, 1884) was reported recently as an aquarium species, but its presence in the natural environmental is currently unknown. One alien species has been introduced each decade since the 1960s. Some species (the barnacles Amphibalanus improvisus (Darwin, 1854), Amphibalanus reticulatus (Utinomi, 1967), and the copepod Lernaea cyprinacea Linnaeus, 1758) were reported as alien species for Ecuador but need verification regarding their current status. Additionally, the barnacle Dosima fascicularis (Ellis and Solander, 1786) presented an occasional record in the Galapagos Islands, but due to its dispersal ability and open ocean habitat it is not possible to conclude that this really is an alien species. The list of alien crustacean species recorded in Ecuador is considered incomplete due to both scarce published work regarding this topic and taxonomic problems. Therefore, it is necessary to carry out more research to establish a complete list of the alien species present in Ecuador and assess their impact on aquatic ecosystems.

Is recorded the species of crabs brachyuran Ucides occidentalis (mangrove crab) and Cardisoma crassum (Blue crab or without mouth) in the mangroves of San Pedro (Piura), expanding its geographical distribution south of Tumbes, which was the known limit. The habitat of these species is characterized by the presence of two varieties of mangrove trees, Jeli white (Laguncularia racemosa) and salty Jeli (Avicenia germinans) and halophytic shrub called glass (Batis maritima), it observing that the depth of the burrows is shallow (<60 cm). Biometric information and some biological aspects of the collected specimens are also presented

Se registra las especies de cangrejos braquiuros Ucides occidentalis (cangrejo del manglar) y Cardisoma crassum (Cangrejo azul o sin boca) en los manglares de San Pedro (Piura), ampliándose su distribución geográfica al sur de Tumbes, que era el límite conocido. El hábitat de estas especies se caracteriza por la presencia de dos variedades de árboles de mangle, jelí blanco (Laguncularia racemosa) y jelí salado (Avicenia germinans) y el arbusto halofítico llamado vidrio (Batis marítima), observándose que la profundidad de las madrigueras investigadas es superficial (< 60 cm). Se presenta además información biométrica y algunos aspectos biológicos de los especímenes colectados