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 Martin Vaz. For a long time, most of the biological information available regarded its islands. Our study presents and analyzes an extensive database on the VTC fish biodiversity, built on data compiled from literature and recent scientific expeditions that assessed both shallow to mesophotic environments. A total of 273 species were recorded, 211 of which occur on seamounts and 173 at the islands. New records for seamounts or islands include 191 reef fish species and 64 depth range extensions. The structure of fish assemblages was similar between islands and seamounts, not differing in species geographic distribution, trophic composition, or spawning strategies. Main differences were related to endemism, higher at the islands, and to the number of endangered species, higher at the seamounts. Since unregulated fishing activities are common in the region, and mining activities are expected to drastically increase in the near future (carbonates on seamount summits and metals on slopes), this unique biodiversity needs urgent attention and management.
The diet and feeding of the cutlass¢sh Trichiurus lepturus were studied based on analyses of the stomach contents of larvae, juveniles, and adults collected along the continental shelf and shelf break o¡ southern Brazil, from the Cape of Santa Marta Grande (28836 0 S) to Chu|¤ (34845 0 S). The larvae and pre-juveniles with a total length of 55 cm were found to have fed almost exclusively on calanoid copepods, whereas juveniles (5 to 30 cm) fed on small zooplanktonic crustaceans such as Lucifer faxoni and Promysys atlantica. On the other hand, sub-adults (30 to 70 cm), fed on euphausiids, mainly Euphausia similis, and small ¢sh, mostly anchovy Engraulis anchoita. Adults (70 to 160 cm) fed on a wide range of larger prey, such as anchovy, sciaenid ¢sh, cephalopods and coastal shrimps, as well as euphausiids. The juveniles and sub-adults fed more intensively than adults during the warm-water season whereas adults fed more intensively during the cold-water season. Feeding activity was more intense at night, while cannibalism was more frequent during the warm season, when biological productivity was lower. Finally, diet diversity was higher in coastal waters, during the warm season. The abundance of cutlass¢sh o¡ southern Brazil may be explained by the fact that it is adapted to feed on a wide size-range of both pelagic and demersal prey.
ABSTRACT. Ninety-three species of bony fishes were caught in 4 seasonal bottom-trawl surveys carried out between July 1986 and May 1987 on the outer shelf and upper slope (124 to 587 m depth) along the southern Brazilian coast (30°40' to 34"30' S). On the outer shelf (< 179 m), the demersalpelagic species Trichiurus lepturus, Trachurus lathami, Cynoscion guatucupa, Scomber japonicus, and Thyrsitops lepidopoides predominated and also to a lesser degree the demersal benthonic Umbrina canosai and Mullus argentinae. Antiyonia capros and Priacanthus arenatus were found associated with the relic coral hard bottoms of the shelf break (180 to 249 m). Further offshore, the demersal-pelagic species Ariomma bondi and Zenopsis conchifera and the demersal benthonic species Polyprion americanus and Helicolenus lahillei were abundant, both associated with rocky bottoms. The macrourids Coelorinchus marinii and Malacocephalus occidentalis characterized deep-water hauls p 4 5 0 m). Frequent and widespread, but less abundant in the catch, were Polymixia lowei, Urophycis mystacea and Merluccius hubbsi. Mean total catch (kg h-') decreased 6-fold and the number of species by more than half along the depth range, with a sharp step at 350 m. Both catch and number of species were slightly higher in the winter cruises. Most species occurred in both winter and summer-autumn cruises, but, with increasing depth, the relative abundance of species that occur year-round decreased, whereas fishes that occur mostly in winter increased. The catch of demersal-pelagic fish decreased sharply below 350 m and differed little among seasons; catches of demersal-benthonic fish were more evenly distributed across the depth range and were larger in winter and spring. The high number of species on the shelf break may be attributable to the higher variety of soft and consolidated substrates and the overlapping of different water masses along the water column. The north-south shift of the western boundary of the Subtropical Convergence appears to be mainly responsible for the seasonal changes in abundance of the species.
We documented the presence of fibropapillomatosis (FP), a debilitating tumor-forming disease, in marine turtles in Espírito Santo Bay (Brazil) from March 2007 to April 2008, and assessed the value of a specific environmental index for predicting the prevalence of FP. Turtles were captured monthly with entanglement nets and scored for presence and severity of FP. For the assessment of habitat quality, we used the ecological evaluation index (EEI) based on benthic macrophytes. The FPfree control area was classified as good quality (EEI = 8) and the study area, with high FP prevalence, was classified as bad quality (EEI = 2). Prevalence of FP in the study area was 58.3% with an average of 40 tumors per individual, and prevalence varied positively with curved carapace length (CCL). No FP was seen in the control area. The number of turtles heavily afflicted (tumor score category 3) was 10 times larger than those lightly affected (tumor score category 1). Most tumors were found on or near the front and rear flippers; no oral tumors or internal tumors were found. At recapture, 41% of formerly tumor-free turtles revealed FP, often increasing in severity with time, and very few turtles showed signs of disease regression. From the results of this study we concluded that FP is particularly severe in Espírito Santo Bay. Future studies should focus on evaluating how widespread FP is in Brazil, whether prevalence is increasing or decreasing, and elucidating the pathology and pathogenesis of FP in sea turtles in Brazil. KEY WORDS: Fibropapillomatosis · Environmental quality · Chelonia mydas · Green turtle · Ecological index · BrazilResale or republication not permitted without written consent of the publisher Dis Aquat Org 89: [87][88][89][90][91][92][93][94][95] 2010 Conservation of Nature and Natural Resources (IUCN) (Seminoff 2004). In addition to anthropogenic threats, diseases such as fibropapillomatosis (FP) may pose additional threats to Chelonia mydas (Herbst 1994, Aguirre et al. 1998.FP is a debilitating disease affecting marine turtles that can impair foraging and internal organ function; it is characterized by the development of tumors on the eyes, oral cavity, skin, carapace, plastron or internal organs (Balazs 1991, Jacobson et al. 1991, Herbst 1994, Aguirre et al. 2002, Work et al. 2004, Foley et al. 2005. The disease mainly affects green turtles (Herbst 1994, Aguirre et al. 1998, 2002, but it has also been documented in other species (George 1997). FP is associated with a herpesvirus (Herbst 1994, Quackenbush et al. 1998, but the role of this agent in causing disease has not been clarified, and it appears other, as yet unidentified, factors probably play a role. It is known that turtles afflicted with FP have higher parasite loads (Work et al. 2005), are immunosuppressed (Work et al. 2001) and bacteraemic (Work et al. 2003).Considerable geographical variation in the prevalence of FP exists (0 to 92%), and substantial differences may be found even between relatively close areas (Ehrhart 1991, Herbst...
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