Owenia caissara sp. n. (Annelida, Oweniidae) from Southern Brazil: addressing an identity crisis

We re-assess the taxonomic status of Owenia Delle Chiaje, 1841 from Southern Brazil based on estuarine specimens from Paranaguá Bay (Paraná) and Babitonga Bay (Santa Catarina), and literature records. Owenia caissara sp. n. is diagnosed by a branchial crown with five pairs of tentacles, branched close to the base of the crown, rectilinear collar with a pronounced lateral slit, two ventrolateral ocelli partially covered by the collar, up to 23 hooks on a single row in the first abdominal segment, regularly curved nuchal shape, regularly moderate teeth curvature, and long and thin scales with oval transition. The description of Owenia caissara sp. n. reinforces the idea that Owenia fusiformis sensu lato is a complex of closely related species that can be distinguished on the basis of both macro- and micro- morphological traits.

Owenia caissara sp. n. (Annelida, Oweniidae) from Southern Brazil: addressing an identity crisis

We re-assess the taxonomic status of Owenia Delle Chiaje, 1841 from Southern Brazil based on estuarine specimens from Paranaguá Bay (Paraná) and Babitonga Bay (Santa Catarina), and literature records. Owenia caissara sp. n. is diagnosed by a branchial crown with five pairs of tentacles, branched close to the base of the crown, rectilinear collar with a pronounced lateral slit, two ventrolateral ocelli partially covered by the collar, up to 23 hooks on a single row in the first abdominal segment, regularly curved nuchal shape, regularly moderate teeth curvature, and long and thin scales with oval transition. The description of Owenia caissara sp. n. reinforces the idea that Owenia fusiformis sensu lato is a complex of closely related species that can be distinguished on the basis of both macro- and micro- morphological traits.(AU)

Composition and abundance of porcellanid crabs (Crustacea: Decapoda: Anomura) from rocky bottoms off Vitória Island, southeast coast of Brazil

This study aimed to describe the species composition and abundance of the porcellanid crabs inhabiting the consolidated sublittoral off an island on the southeastern coast of Brazil. During a sampling program at Vitória Island (23º44'S, 45º01'W), collections were carried out monthly from February 2004 through January 2006. The crabs were hand-caught by SCUBA divers during the daytime. The greatest carapace width (CW) was measured, and the sex and developmental stage were identified for each crab. The specimens were grouped into five demographic categories: juvenile males, adult males, juvenile females, adult females, and ovigerous females. A total of 275 crabs belonging to three genera and six species were obtained. Petrolisthes amoenus (Guérin-Méneville, 1855) and Pachycheles riisei (Stimpson, 1858) were the most abundant species. Most of the demographic classes were represented for both species, except that no adult females of P. riisei were recorded. Among the porcellanids, Pachycheles monilifer (Dana, 1852) was the dominant species; it comprised more than 75% of the total individuals sampled, and showed the highest constancy index for the region. The results obtained in this study provided information regarding the faunal composition and the relative abundance of the species, which will be useful as a reference for other sublittoral consolidated-bottom regions along the southeast Brazilian coast.

Composition and abundance of porcellanid crabs (Crustacea: Decapoda: Anomura) from rocky bottoms off Vitória Island, southeast coast of Brazil

This study aimed to describe the species composition and abundance of the porcellanid crabs inhabiting the consolidated sublittoral off an island on the southeastern coast of Brazil. During a sampling program at Vitória Island (23º44'S, 45º01'W), collections were carried out monthly from February 2004 through January 2006. The crabs were hand-caught by SCUBA divers during the daytime. The greatest carapace width (CW) was measured, and the sex and developmental stage were identified for each crab. The specimens were grouped into five demographic categories: juvenile males, adult males, juvenile females, adult females, and ovigerous females. A total of 275 crabs belonging to three genera and six species were obtained. Petrolisthes amoenus (Guérin-Méneville, 1855) and Pachycheles riisei (Stimpson, 1858) were the most abundant species. Most of the demographic classes were represented for both species, except that no adult females of P. riisei were recorded. Among the porcellanids, Pachycheles monilifer (Dana, 1852) was the dominant species; it comprised more than 75% of the total individuals sampled, and showed the highest constancy index for the region. The results obtained in this study provided information regarding the faunal composition and the relative abundance of the species, which will be useful as a reference for other sublittoral consolidated-bottom regions along the southeast Brazilian coast.

Composition and abundance of porcellanid crabs (Crustacea: Decapoda: Anomura) from rocky bottoms off Vitória Island, southeast coast of Brazil

This study aimed to describe the species composition and abundance of the porcellanid crabs inhabiting the consolidated sublittoral off an island on the southeastern coast of Brazil. During a sampling program at Vitória Island (23º44'S, 45º01'W), collections were carried out monthly from February 2004 through January 2006. The crabs were hand-caught by SCUBA divers during the daytime. The greatest carapace width (CW) was measured, and the sex and developmental stage were identified for each crab. The specimens were grouped into five demographic categories: juvenile males, adult males, juvenile females, adult females, and ovigerous females. A total of 275 crabs belonging to three genera and six species were obtained. Petrolisthes amoenus (Guérin-Méneville, 1855) and Pachycheles riisei (Stimpson, 1858) were the most abundant species. Most of the demographic classes were represented for both species, except that no adult females of P. riisei were recorded. Among the porcellanids, Pachycheles monilifer (Dana, 1852) was the dominant species; it comprised more than 75% of the total individuals sampled, and showed the highest constancy index for the region. The results obtained in this study provided information regarding the faunal composition and the relative abundance of the species, which will be useful as a reference for other sublittoral consolidated-bottom regions along the southeast Brazilian coast.