High levels of population genetic differentiation in the American crocodile (Crocodylus acutus)

The American crocodile (Crocodylus acutus) is a widely distributed species across coastal and brackish areas of the Neotropical region of the Americas and the Greater Antilles. Available information on patterns of genetic differentiation in C. acutus shows a complex structuring influenced by interspecific interactions (mainly hybridization) and anthropogenic actions (mostly historical hunting, recent poaching, habitat loss and fragmentation, and unintentional translocation of individuals). In this study, we used data on mitochondrial DNA control region and 11 nuclear polymorphic microsatellite loci to assess the degree of population structure of C. acutus in South America, North America, Central America and the Greater Antilles. We used traditional genetic differentiation indices, Bayesian clustering and multivariate methods to create a more comprehensive picture of the genetic relationships within the species across its range. Analyses of mtDNA and microsatellite loci show evidence of a strong population genetic structure in the American crocodile, with unique populations in each sampling locality. Our results support previous findings showing large degrees of genetic differentiation between the continental and the Greater Antillean C. acutus. We report three new haplotypes unique to Venezuela, which are considerably less distant from the Central and North American haplotypes than to the Greater Antillean ones. Our findings reveal genetic population differentiation between Cuban and Jamaican C. acutus and offer the first evidence of strong genetic differentiation among the populations of Greater Antillean C. acutus

Observaciones a la flora y vegetación de costa arenosa en el Refugio de Fauna Monte Cabaniguán-Ojo de Agua, Las Tunas, Cuba

As a result of an exploratory study and rapid assessment demanded by the SOS Fishing, an International Project coordinated by Cuba's National Center for Protected Areas, the results derived from such investigative actions are presented. For it report, we developed different field trips as a transects, in different sectors of the protected area Fauna Refuge Monte Cabaniguán-Ojo de Agua, belonging to Las Tunas province, site of special interest for population conservation of Crocodylus acutus Cuvier, 1807 (American Crocodile). After the field actions and in the office, the material obtained was processed, including details on the determinations nomenclatural taxa of flora found; also we helpers in preliminary background assessments that had been made by the Management Plan of that protected area. In the sandy coast ecotopes analyzed were determined 45 species of higher plants belonging to 18 families, all of which 22.2% of all species inventoried in this expedition are invasive alien species, as reported by CENBIO (2013). The new list of species updates the existing previous version is presented, and it highlights new reports by nomenclatural and new records for this area updates. Criteria on the state of the dune ecosystem are also exposed and recommendations for the management of key species American Crocodile are issued.Como resultado de un estudio exploratorio y de evaluación rápida, demandado por el Proyecto Internacional SOS Pesca que coordina en Cuba el Centro Nacional de Áreas Protegidas, se presentan los resultados derivados de tales acciones investigativas, para lo cual desarrollaron recorridos tipo transectos en diferentes sectores del área protegida Refugio de Fauna Monte Cabaniguán-Ojo de Agua, perteneciente a la provincia Las Tunas, sitio de especial interés para la conservación de poblaciones de la especie Crocodylus acutus Cuvier, 1807 (Cocodrilo americano). Después de las acciones de campo y de gabinete en la propia área se procesó el material obtenido, incluyendo precisiones en las determinaciones nomenclaturales de taxones de la flora encontrados; también auxiliándonos de evaluaciones antecedentes premilimares que se habían hecho para el Plan de Manejo de la citada área protegida. En los ecótopos de costa arenosa analizados, fueron determinadas 45 especies de plantas superiores pertenecientes todas ellas a 18 familias, de las cuales el 22,2% del total de las especies inventariadas en esta expedición son especies exóticas invasoras, según reporta CeNBIO. 2013. Se presenta la Lista de especies confeccionada que actualiza la versión anterior existente, y de ella además se destacan nuevos reportes por actualizaciones nomenclaturales y nuevos registros para esta área. También se exponen criterios sobre el estado del ecosistema dunar y se emiten recomendaciones para el manejo de la especie clave Cocodrilo americano

Data from: Genetic evidence of hybridization between the critically endangered Cuban crocodile and the American crocodile: implications for population history and in situ/ex situ conservation

Inter-specific hybridization may be especially detrimental when one species is extremely rare and the other is abundant owing to the potential for genetic swamping. The Cuban crocodile (Crocodylus rhombifer) is a critically endangered island endemic largely restricted to Zapata Swamp, where it is sympatric with the widespread American crocodile (C. acutus). An on-island, C. rhombifer captive breeding program is underway with the goals of maintaining taxonomic integrity and providing a source of individuals for reintroduction, but its conservation value is limited by lack of genetic information. Here we collected mtDNA haplotypic and nuclear genotypic data from wild and captive C. rhombifer and C. acutus in Cuba to: (1) investigate the degree of inter-specific hybridization in natural (in situ) and captive (ex situ) populations; (2) quantify the extent, distribution and in situ representation of genetic variation ex situ; and (3) reconstruct founder relatedness to inform management. We found high levels of hybridization in the wild (49.1%) and captivity (16.1%), and additional evidence for a cryptic lineage of C. acutus in the Antilles. We detected marginally higher observed heterozygosity and allelic diversity ex situ relative to the wild population, with captive C. rhombifer exhibiting over twice the frequency of private alleles. Although mean relatedness was high in captivity, we identified 37 genetically important individuals that possessed individual mean kinship (MK) values lower than the population MK. Overall, these results will guide long-term conservation management of Cuban crocodiles for maintaining the genetic integrity and viability of this species of high global conservation value

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