Gill Histopathological Biomarkers in Fish Exposed to Trace Metals in the Todos os Santos Bay, Brazil.

Histopathologies are widely recognized as biomarkers of environmental pollution. In this sense, we evaluated the putative relationship of gill histopathologies and distinct ecological impacts in two regions of Todos os Santos Bay (BTS), Brazil, the largest bay in Northeastern Brazil, South Atlantic. We compared the presence and concentration of metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn) in water, sediments, and gills and gill histopathologies of a demersal fish (Diapterus rhombeus) and a benthic fish (Ogcocephalus vespertilio). As expected, fish and sediment samples from historically contaminated areas (Aratu) showed more remarkable traces of metals than apparently low-impact areas (Jaguaripe). Likewise, the DTC (degree of tissue change) index and the volume densities were higher in fish caught in Aratu. In addition, the Diapterus rhombeus species showed more potential than Ogcocephalus vespertilio for risk assessment as it showed more responses to the environment reflected on more histopathologies. These data support the effectiveness of incorporating functional gill morphology to monitor impacts on estuarine biota that can be used as a reference to improve the management of ecosystems and prevent harm to human health.

A new species of viviparous brotula genus Pseudogilbia (Ophidiiformes: Dinematichthyidae) from Brazilian reefs, with an updated diagnosis of the genus.

In this study, a new species of Pseudogilbia Møller, Schwarzhans & Nielsen 2004 is described based on two male specimens (40-44 mm LS ) from shallow reefs of Bahia, Brazil. Pseudogilbia australis sp. nov. is distinguished from its only congener, Pseudogilbia sanblasensis Møller, Schwarzhans & Nielsen 2004 from Caribbean Panama, by having: two lower preopercular pores (vs. one); dorsal-fin rays 65-67 (vs. 69); anal-fin rays 51-53 (vs. 56); pectoral-fin rays 18 (vs. 20); caudal vertebrae 27-28 (vs. 30); pectoral-fin length 15.0%-15.9% LS (vs. 14.3); pelvic-fin length 13.5% LS (vs. 16.4) and a different morphology of the male copulatory organ. Pseudogilbia australis sp. nov. is the only dinematichthyid so far recorded in the South Atlantic. An updated diagnosis for the genus is also provided.

Choosing trash instead of nature: Sea urchin covering behavior.

Notwithstanding impacts of marine debris on fauna by ingestion and suffocation, little is known about debris-related behavior. Lytechinus variegatus is a common sea urchin known for its covering behavior. We hypothesized that L. variegatus would select more marine debris (i.e. litter) than natural material as cover and we also expected that the selected natural and artificial material would be different in weight, sizes and transparency. We haphazardly collected marine debris and natural material on 20 individuals of L. variegatus and on the bottom, around each individual. All sampled material was weighed, measured and classified regarding opacity, nature (natural or artificial). Our results showed that i) sea urchins picked more litter than natural objects, ii) proportional weight of litter carried by urchins was significantly larger than expected by chance, iii) when considering all objects (on urchins and on the bottom) litter was heavier, wider and less opaque than natural material and iv) litter carried by the urchins were wider and less opaque than natural material. We suggest that litter can influence urchin's protection against sunlight, camouflage and ballast and that sea urchins with covering behavior might be used as indicators of marine debris in coastal and deep waters.

Global trends on reef fishes' ecology of fear: Flight initiation distance for conservation.

Escape behaviors have a great potential as an indicator of the efficacy of management. For instance, the degree of fear perceived by fishes targeted by fisheries is frequently higher in unprotected marine areas than in areas where some protection is provided. We systematically reviewed the literature on how fear, which we define as variation in escape behavior, was quantified in reef fishes. In the past 25 years, a total of 33 studies were identified, many of which were published within the last five years and nearly 40% of those (n = 13) focused on Indo-Pacific reefs, showing that there are still many geographical gaps. While eleven escape metrics were identified to evaluate fish escape, flight initiation distance (FID) was the most commonly employed (n = 23). FID was used to study different questions of applied and theoretical ecology, which involved 14 reef fish families. We also used a formal meta-analysis to investigate the effects of fishing by comparing FID inside and outside marine protected areas. Fishes outside MPAs had increased FID compared to those inside MPAs. The Labridae family had a significantly higher effect sizes than Acanthuridae and Epinephelidae, suggesting that fishes in this family may be indicators of effective MPAs using FID. We conclude that protocols aimed to quantify fear in fishes, which provide accurate assessments of fishing effects on fish escape behavior, will help gauge the compliance of marine protected areas.