DESCRIPTION OF THE MALE REPRODUCTIVE SYSTEM OF THE HERMIT CRAB CALCINUS TIBICEN (DECAPODA: ANOMURA: DIOGENIDAE)

We describe the male reproductive system of the intertidal hermit crab Calcinus tihicen, with emphasis on the sexual apparatus, spermatophore, and spermatozoa. The crabs were collected on the rocky shore of Praia Grande Beach, Ubatuba, southeastern Brazil. The morphological analysis, based on 30 specimens, was made with the use of a stereomicroscope, an optical microscope, and scanning and transmission electron microscopes. The male reproductive system is composed of a pair of juxtaposed testes, located dorsally in the pleon. From each testis emerges a vas deferens that links it to the exterior by the gonopores. located on the base of the fifth pair of pereiopods. The vas deferens has three macroscopically distinct regions that contain spermatophores in different stages of maturation. The spermatophore morphology is similar to that of other members of Paguroidea, having a distal, nearly spherical ampulla containing spermatozoa; an approximately cylindrical peduncle and a proximal foot connecting the spermatophores. We describe, for the first time, the variability in the spermatophore morphology and size in the three regions of the vas deferens using the type species of the genus Calcinus. The spermatozoa have three main regions (the acrosomal vesicle, the nucleus, and the cytoplasm). The morphological similarity of the male reproductive system of C. tihicen with previously studied species of Diogenidae is an indicative of complex phylogenetic relationships among the members of the genus.FAPESP[06/58863-0]CNPq[301359/2007-5

Reproductive system of the male hermit crab Clibanarius sclopetarius: gonopore, spermatophore, and spermatozoal morphologies

In the present study, the morphology and biometry of the spermatophores of the western Atlantic hermit crab Clibanarius sclopetarius (Herbst, 1796) are described, and the results are placed in the context of the Paguroidea, in particular the Diogenidae. Individuals of C. sclopetarius were sampled from a human-impacted mangrove area of southern Brazil. The male reproductive system was removed, measured and analyzed using stereoscopic, light, transmission-electron and scanning-electron microscopy. This system is composed of lobular testes connected to the vas deferens, and gonopores with membranous coverage. The mature spermatophore consists of a spherical pack that stores sperm. These cells consist of a spherical acrosomal vesicle, an amorphous cytoplasm and a distal nucleus. The results revealed that the gonopores, testis and vas deferens have the expected characteristics of the family Diogenidae, while the non-tripartite morphology of the spermatophores and the sperm follow the patterns found only in the genus Clibanarius, and the presence of the dense perforatorial ring is, to date, unique in the species of the genus, being a possible apomorphic characteristic.CNPq Conselho Nacional de Desenvolvimento Cientifico e TecnologicoCNPq[301359/2007-5]CNPq[302748/2010-5]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2010/50188-8

Patrones de distribución del cangrejo ermitaño "Loxopagurus loxochelis" (Moreira, 1901) (Decapoda, Diogenidae) en dos áreas de la costa sudeste de Brasil

The present study determined the distribution pattern of the hermit crab Loxopagurus loxochelis by a comparison of catch, depth and environmental factors at two separate bays (Caraguatatuba and Ubatuba) of São Paulo State, Brazil. The influence of these parameters on the distribution of males, non-ovigerous females and ovigerous females was also evaluated. Crabs were collected monthly, over a period of one year (from July/2002 to June/2003), in seven depths, from 5 to 35 m. Abiotic factors were monitored as follows: superficial and bottom salinity (psu), superficial and bottom temperature (°C), organic matter content (%) and sediment composition (%). In total, 366 hermit crabs were sampled in Caraguatatuba and 126 in Ubatuba. The highest frequency of occurrence was verified at 20 m during winter (July) in Caraguatatuba and 25 m during summer (January) in Ubatuba. The highest occurrences were recorded in the regions with bottom salinities ranging from 34 to 36 psu, bottom temperatures from 18 to 24°C and, low percentages of organic matter, gravel and mud; and large proportion of sand in the substrate. There was no significant correlation between the total frequency of organisms and the environmental factors analyzed in both regions. This evidence suggests that other variables as biotic interactions can influence the pattern of distribution of L. loxochelis in the analyzed region, which is considered the limit of the northern distribution of this species.El presente estudio determinó el patrón de distribución del cangrejo ermitaño Loxopagurus loxochelis por medio una comparación de la captura, profundidad y factores ambientales en dos bahías separadas (Caraguatatuba y Ubatuba) del estado de São Paulo, Brasil. También se evaluó la influencia de parámetros medioambientales sobre la distribución de machos, hembras y hembras ovígeras. Los cangrejos se recolectaron mensualmente en las dos áreas de estudio, durante un año (julio de 2002 a junio de 2003), en siete profundidades, entre 5 y 35 m. Se registraron los factores abióticos: salinidad (psu) y temperatura (°C) en la superficie así como en el fondo, contenido de materia orgánica (%) y composición del sedimento (%). Se recolectó un total de 366 cangrejos en Caraguatatuba y 126 en Ubatuba. La mayor frecuencia de individos se obtuvo a una profundidad de 20 m en Caraguatatuba durante el invierno (julio) y a una profundidad de 25 m en Ubatuba durante el verano (enero). Las mayores frecuencias se registraron en áreas con salinidades entre 34 y 36 psu en el fondo, temperaturas entre 18 y 24°C también en el fondo y sustratos con bajos porcentajes de materia orgánica, grava y lodo, así como con altas proporciones de arena. No se encontró correlación significativa entre la frecuencia total de organismos y los factores medioambientales analizados en ninguna de las dos regiones. Estos resultados sugieren que algún otro factor ambiental o interacción biótica podría ser responsable de los patrones de distribución de L. loxochelis en las regiones estudiadas, consideradas zonas limítrofes de la distribución norte del cangrejo ermitaño