Does the colors of light matter? Testing different light color in nocturnal underwater visual censuses.

Most methods for assessing reef fish assemblages at night require artificial light, but the use of different colors of light may influence the results. We used data from 135 underwater visual censuses (UVCs) performed with different colors of light (red, blue and white) to evaluate the structure of fish assemblages on subtropical rocky reefs along three depth intervals. We did not detect any effect of the color of light on total density or fish species richness per transect, nor on the structure of the entire assemblage. However, the density of some of the most abundant species varied according to the color used. Red light showed the highest values of frequency of occurrence for most species, while the white light resulted in decreased abundance of some fish species. Our results emphasize the importance of choosing the color of light depending on the type of studies to be conducted. This will depend on the objectives of the research (e.g. inventory, behavior or community dynamics) and the target fish fauna (e.g. mobile or sedentary).

First Record of Invasive Lionfish (Pterois volitans) for the Brazilian Coast.

The invasion of the northwestern Atlantic by the Indo-Pacific lionfish has developed extraordinarily fast, and is expected to cause one of the most negative ecological impacts among all marine invasions. In less than 30 years, lionfish have dramatically expanded their distribution range to an area encompassing the eastern coast of the USA, Bermuda, the entire Caribbean region and the Gulf of Mexico. The rapidity of the lionfish spread has raised concerns in other parts of the Atlantic that may be under the reach of the invasion. Despite the anticipation that lionfish would eventually extend their range throughout most of the eastern coast of South America, it had not been recorded in Brazil until now. Here we report the first lionfish appearance for the Brazilian coast and show that the individual collected by us is genetically linked to the invasive Caribbean population. Since small-range endemics are found in several locations in Brazil and are among the species that are most vulnerable to extinction, we recommend urgent control, management and education measures aimed at minimizing the effects of this impending invasion.