Genetic evidence supports a distinct lineage of American crocodile (Crocodylus acutus) in the Greater Antilles.

Four species of true crocodile (genus Crocodylus) have been described from the Americas. Three of these crocodile species exhibit non-overlapping distributions-Crocodylus intermedius in South America, C. moreletii along the Caribbean coast of Mesoamerica, and C. rhombifer confined to Cuba. The fourth, C. acutus, is narrowly sympatric with each of the other three species. In this study, we sampled 113 crocodiles across Crocodylus populations in Cuba, as well as exemplar populations in Belize and Florida (USA), and sequenced three regions of the mitochondrial genome (D-loop, cytochrome b, cytochrome oxidase I; 3,626 base pair long dataset) that overlapped with published data previously collected from Colombia, Jamaica, and the Cayman Islands. Phylogenetic analyses of these data revealed two, paraphyletic lineages of C. acutus. One lineage, found in the continental Americas, is the sister taxon to C. intermedius, while the Greater Antillean lineage is most closely related to C. rhombifer. In addition to the paraphyly of the two C. acutus lineages, we recovered a 5.4% estimate of Tamura-Nei genetic divergence between the Antillean and continental clades. The reconstructed paraphyly, distinct phylogenetic affinities and high genetic divergence between Antillean and continental C. acutus populations are consistent with interspecific differentiation within the genus and suggest that the current taxon recognized as C. acutus is more likely a complex of cryptic species warranting a reassessment of current taxonomy. Moreover, the inclusion, for the first time, of samples from the western population of the American crocodile in Cuba revealed evidence for continental mtDNA haplotypes in the Antilles, suggesting this area may constitute a transition zone between distinct lineages of C. acutus. Further study using nuclear character data is warranted to more fully characterize this cryptic diversity, resolve taxonomic uncertainty, and inform conservation planning in this system.

An inducible nitric oxide synthase (NOS) is expressed in hemocytes of the spiny lobster Panulirus argus: cloning, characterization and expression analysis.

Nitric oxide (NO) is a free radical gas involved in a variety of physiological processes in invertebrates, such as neuromodulation, muscle contraction and host defense. Surprisingly, little is known about the involvement of NO synthase (NOS) in the immune system of crustaceans. This work is focused on the study of the NOS gene of the spiny lobster Panulirus argus, a crustacean with commercial interest, and its relationship with the immune response to a microbial elicitor. A NOS full-length DNA was isolated from hemocytes by reverse transcription-polymerase chain reaction (RT-PCR) using degenerated primers. The open reading frame (ORF) encodes a protein of 1200 amino acids, with an estimated molecular mass of 135.9 kDa, which contains the conserved domains and binding motifs of NOS found in a variety of organisms. NOS gene expression in lobster gills, heart, stomach, digestive gland, abdominal muscle, gut and hemocytes was studied by Real Time quantitative PCR (Real Time qPCR). The expression was higher in hemocytes, heart and gills. In addition, when lobster hemocytes were exposed in vitro to Escherichia coli O55:B5 lipopolysaccharide (LPS), an increase in the NOS activity and also in the NOS gene expression evaluated by Real Time qPCR was observed, thus demonstrating the presence of an inducible crustacean NOS by a microbial elicitor of the immune response. The information is relevant in providing basic knowledge for further studies of crustacean defense mechanisms.

[Gonadic histology and phenotypical maturation criteria in the marine turtles Chelonia mydas and Eretmochelys imbricata (Testudines: Chelonidae) from Cuba]. / Histología gonadal y criterios fenotípicos de maduración en las tortugas marinas Chelonia mydas y Eretmochelys imbricata (Testudines: Chelonidae) de Cuba.

Gonad maturity is usually evaluated through macroscopic analysis of the gonads. In sea turtles, the maturation stages are associated with body size, depending on the studied marine stock. Fishermen classify turtles bigger than 65.0 cm as sexually mature. If they have secondary sex characters they are recorded as breeding males. We compared body size with macroscopic and microscopic gonad characteristics in two Cuban turtles. Eighteen individuals of C. mydas and twenty of E. imbricata was obtained from the legal fishery stock of Jardines del Rey Archipelago (Cuba), from October 2005 and 2006. In males, breeding condition (maximum spermiogenesis) was checked by histological analysis of the testes. In females, sexual maturity was identified by the presence of vitellogenic follicles or ovarian corpora. Most males were immature (C. mydas: 79.0 cm; E. imbricata: 73.1+/-4.9 cm, n=3) and lacked secondary sex characters. Some E. imbricata without a developed penis were in spermatogenic stages II to IV (i.e. pubescent). Most females were immature (C. mydas: 79.6+/-7.7 cm, n=17; E. imbricata: 69.0+/-7.1 cm, n=16; i.e.prepubescent and pubescent. The prepubescent females had ovaries with previtellogenic follicles near 1.0 mm in a compact and yellowish stroma. The pubescent females had ovaries with previtellogenic follicles between 2.0 and 3.0 mm. The stroma was more loosened and irrigated than in prepubescent turtles. The finding of spermatogenic activity in pubescent males indicates asynchrony between testicular and penial development in E. imbricata. The current phenotypical approach used by fishermen is not enough to determine sexual maturation in these turtles. The minimal size tentatively should be changed to: C. mydas: above 93.0 cm and E. imbricata above 79.0 cm.

Histología gonadal y criterios fenotípicos de maduración en las tortugas marinas Chelonia mydas y Eretmochelys imbricata (Testudines: Chelonidae) de Cuba

Gonadic histology and phenotypical maturation criteria in the marine turtles Chelonia mydas and Eretmochelys imbricata (Testudines: Chelonidae) from Cuba. Gonad maturity is usually evaluated through macroscopic analysis of the gonads. In sea turtles, the maturation stages are associated with body size, depending on the studied marine stock. Fishermen classify turtles bigger than 65.0cm as sexually mature. If they have secondary sex characters they are recorded as breeding males. We compared body size with macroscopic and microscopic gonad characteristics in two Cuban turtles. Eighteen individuals of C. mydas and twenty of E. imbricata was obtained from the legal fishery stock of Jardines del Rey Archipelago (Cuba), from October 2005 and 2006. In males, breeding condition (maximum spermiogenesis) was checked by histological analysis of the testes. In females, sexual maturity was identified by the presence of vitellogenic follicles or ovarian corpora. Most males were immature (C. mydas: 79.0cm; E. imbricata: 73.1±4.9cm, n=3) and lacked secondary sex characters. Some E. imbricata without a developed penis were in spermatogenic stages II to IV (i.e. pubescent). Most females were immature (C. mydas: 79.6±7.7cm, n=17; E. imbricata: 69.0±7.1cm, n=16; i.e.prepubescent and pubescent. The prepubescent females had ovaries with previtellogenic follicles near 1.0mm in a compact and yellowish stroma. The pubescent females had ovaries with previtellogenic follicles between 2.0 and 3.0mm. The stroma was more loosened and irrigated than in prepubescent turtles. The finding of spermatogenic activity in pubescent males indicates asynchrony between testicular and penial development in E. imbricata. The current phenotypical approach used by fishermen is not enough to determine sexual maturation in these turtles. The minimal size tentatively should be changed to: C. mydas: above 93.0cm and E. imbricata above 79.0cm. Rev. Biol. Trop. 58 (1): 287-298. Epub 2010 March 01.

La madurez gonadal se suele evaluar a través del análisis macroscópico de las gónadas. En las tortugas marinas, las etapas de maduración están asociadas con el tamaño del cuerpo, dependiendo de la población estudiada. Los pescadores clasifican las tortugas que miden más de 65.0cm como maduras sexualmente. Si tienen los caracteres sexuales secundarios se registran como machos en edad reproductora. Nosotros comparáramos el tamaño del cuerpo con las características gonadales macroscópicas y microscópicas de dos tortugas de Cuba. Se obtuvieron dieciocho individuos de C. mydas y veinte de E. imbricata en la pesquería legal del Archipiélago Jardines del Rey (Cuba), entre octubre de 2005 y 2006. En los machos, el estado reproductivo (máxima espermiogénesis) se comprobó mediante el análisis histológico de los testículos. En las hembras, la madurez sexual fue identificada por la presencia de folículos vitelogénicos u ovarios corpora. La mayoría de los machos eran inmaduros (C. mydas: 79.0cm; E. imbricata: 73.1±4.9cm, n=3) y carecían de los caracteres sexuales secundarios. Algunos E. imbricata que no tenían un pene desarrollado se encontraban en fases espermatogénicas entre II y IV (p. ej. pubescentes). La mayoría de las hembras eran inmaduras (C. mydas: 79.6±7.7cm, n=17; E. imbricata: 69.0±7.1cm, n=16; p. ej. prepubescente y pubescente). Las hembras prepubescentes tenían ovarios con folículos previtelogénicos de cerca de 1.0mm en un estroma compacto y amarillento. Las hembras pubescentes tenían ovarios con folículos previtelogénicos entre 2.0 y 3.0mm. El estroma fue más distendido e irrigado que en las tortugas pubescentes. El hallazgo de actividad espermatogénica en machos pubescentes indica la asincronía entre el desarrollo de testículos y pene en E. imbricata. El criterio fenotípico actual utilizado por los pescadores no es suficiente para determinar la madurez sexual de estas tortugas. La talla mínima tentativa debe cambiar a: C. mydas: por encima de 93.0cm y E. imbricata por encima de 79.0cm.