Jean-Christophe Joyeux

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Despite a strong increase in research on seamounts and oceanic islands ecology and biogeography, many basic aspects of their biodiversity are still unknown. In the southwestern Atlantic, the Vitória-Trindade Seamount Chain (VTC) extends ca. 1,200 km offshore the Brazilian continental shelf, from the Vitória seamount to the oceanic islands of Trindade and(More)
Age, growth rates and hatching dates were determined for juvenile common snook, Centropomus undecimalis, collected in several Puerto Rican estuarine systems. Two growth models (von Bertalanffy and power curve) were used and compared based on the fitting, the residual distribution and homogeneity of variances. A multiple linear regression was also fit to(More)
Invasive coral species of the genus Tubastraea have been increasingly recorded in Southwestern Atlantic waters since the 1980s. Their invasion and infestation are mainly related to port and oil exploration activities. For the first time the presence of Tubastraea tagusensis colonies is reported in Espírito Santo State, colonizing a port shore area, and(More)
The genus Lythrypnus is a group of marine gobies that exhibit extreme gender flexibility as bidirectional sex changers. The genus consists of 20 described species and several undescribed species that are distributed in the Americas. Five species have been characterized with respect to sex allocation and gonad morphology. The hormonal, morphological, and(More)
Topics in artificial reef research have included a wide number of themes but a major portion of published works are about the attraction that artificial reefs exert over fishes that reside in natural reefs. In the present work, underwater visual censuses of fishes were conducted at both artificial and natural reefs, aiming at verifying whether fishes are(More)
Dispersal is fundamental to the colonization of oceanic islands that were never connected to larger landmasses. For species with limited dispersal capabilities, colonization of remote islands can be followed by isolation and speciation. The tidepool fish community of Trindade Island, 1,160 km off the Brazilian coast at the eastern end of the(More)
In the present work fish assemblages over two metallic vessels, five and 105 years old, and two natural rocky reefs were compared. The hypothesis that shipwrecks support assemblages with trophic structure similar to that encountered on natural reefs was rejected. Artificial and natural reefs strongly differ in their trophic structure, both in their(More)
Seamounts are considered important sources of biodiversity and minerals. However, their biodiversity and health status are not well understood; therefore, potential conservation problems are unknown. The mesophotic reefs of the Vitória-Trindade Seamount Chain (VTC) were investigated via benthic community and fish surveys, metagenomic and water chemistry(More)
Three cases of color abnormalities and one of morphological aberration in flatfishes of the genus Achirus are described from the Piraquê-Açú River estuary, Espírito Santo, Brazil. One specimen of A. declivis has 75% of the blind side with coloration like that of the ocular side. Another specimen of the same species is strongly hypomelanistic. A third(More)