RESUMO
Introduction: Brazil has more than 8 000 km of coastline but its marine invertebrates are still poorly known. The cirratulid polychaetes have been an especially neglected group because of its challenging taxonomy. Objective: To describe a new species of Protocirrineris. Methods: In a recent survey in two of the largest Brazilian bays, Todos os Santos Bay and Camamu Bay, 84 specimens of four morphotypes of the multitentaculate genus Protocirrineris were collected. Because of the lack of modified chaetae, the taxonomy of Protocirrineris is challenging and only two of these morphotypes are herein described as new species. Results: These two new species are characterized by having tentacular filaments in two groups over chaetigers 3-4 and first branchiae present from chaetiger 1. They differ from each other in relation to the nature of the achaetigerous region, posterior region, ultrastructure of capillary chaetae and methyl green staining pattern. Two incomplete specimens are also considered as Protocirrineris, and brief descriptions are given. Conclusions: The genus Protocirrineris is cited for the first time in Brazil. Four new morphotypes were found in two large estuaries of Brazil, and two new species are formally described.
Introducción: Brasil tiene más de 8000 km de costa, pero sus invertebrados marinos aún son poco conocidos. Los poliquetos cirratulidos han sido un grupo especialmente descuidado debido a su desafiante taxonomía. Objetivos: Identificar morfotipos de Cirratulidae multitentaculados y encontrar nuevos caracteres diagnósticos. Métodos: En muestreo reciente en dos de las bahías más grandes de Brasil, Bahía de Todos los Santos y Bahía de Camamu, se colectaron cuatro morfotipos del género multitentaculado Protocirrineris. Resultados: Debido a la falta de quetas modificada, la taxonomía de Protocirrineris es un desafío y solo dos de estos morfotipos se describen aquí como nuevas especies. Estas dos nuevas especies se caracterizan por tener filamentos tentaculares en dos grupos sobre los quetígeros 3-4 y las primeras branquias presentes de quetígero 1. Se diferencian entre sí en relación con la naturaleza de la región sin quetas, región posterior, ultraestructura de las quetas capilares y el patrón de tinción con verde de metilo. Dos especímenes incompletos también se consideran Protocirrineris, y se dan breves descripciones. Conclusiones: Se cita por primera vez la presencia del género Protocirrineris en Brasil. Cuatro morfotipos del género han sido encontrados en dos grandes estuarios de Brasil. Dos especies nuevas para la ciencia son descriptas.
RESUMO
This study assessed the species composition, distribution, and functional profiles of cyanobacteria in Camamu Bay, a tropical oligotrophic estuarine system on the northeast coast of Brazil, using shotgun metagenomic sequencing. Surface-water samples were evaluated in two different rainfall periods (rainy and dry seasons), at nine stations in the three hydrodynamic regions of the bay. At a fixed sampling station, on each season, samples were taken over a tidal cycle at 3-h intervals over 12 h. A total of 219 cyanobacterial taxa were identified, demonstrating a diverse community of freshwater, euryhaline, and marine cyanobacteria. The genera of greater relative abundance, Synechococcus and Prochlorococcus, corresponded to the picoplankton fraction. Although Camamu Bay has conspicuous marine characteristics, the contribution of freshwater during the rainy season caused variation in cyanobacteria community, with an increase in species richness. Due the high prevalence of Synechococcus (90% of the sequences), the functional analysis revealed only minor differences in gene content between the dry and rainy seasons. In both rainy and dry seasons, an increase in Prochlorococcus relative abundance occurred during high tide, demonstrating the tidal influence in the bay. The environmental characteristics of the bay provide niche conditions for a wide variety of cyanobacteria, including freshwater, euryhaline, and marine strains.
RESUMO
References areas are sites that have undergone little or no anthropogenic impact and therefore represent the natural state of an environment. The objective of this study was to test if the Camamu Bay (CB), Bahia, can be used as a reference area for tropical coastal environments. Trace and major elements, polycyclic aromatic hydrocarbons (PAH), and the structure of the benthic macrofauna were determined. To compare the studied sites and identify the possible occurrence of anomalous concentrations, trace elements were normalized by Al and linear regressions were also performed. For all trace elements (except Cu), regressions showed a significant correlation (p<0.05) and few outliers (<3% of cases), showing that the concentrations found represent natural values for this bay. In the case of Cu, the highest concentrations were found near small municipalities, which may be associated with domestic sewage. About 60% of the organic compounds occurred at levels below the limit of quantification (<0.26ngg-1). The sum of PAHs was low for all stations, ranging from 1.17 to 313ngg-1. The benthic assemblages also indicated that the CB is a healthy, well-preserved ecosystem that deserves conservation efforts. The integrated use of geochemical and biotic data supported the use of CB as a reference area. Capsule: Organic and inorganic contaminants together with macrobenthic assemblages indicated that Camamu Bay is a pristine, tropical reference area.