Search

Copyright of Neotropical Ichthyology is the property of Neotropical Ichthyology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Neotropical Ichthyology is the property of Neotropical Ichthyology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cambeva piraquara, sp. nov., a restricted-range and rare species last collected from over 20 years ago, is described from the Rio Piraquara, upper Rio Iguaçu basin, Rio Paraná (La Plata) system. The new species is distinguished from all congeners by having two conspicuous dark-brown longitudinal stripes on the inner skin layer of body over a plain yellowish background: a conspicuous wide and well-defined dark-brown longitudinal mid-lateral stripe extending from the opercular patch of odontodes to the first third of caudal-fin rays and a dorso-sagittal stripe comprising large and coalescent rounded blotches extending from occipital to the dorsal-fin base. We provide an illustrated osteological description and assess the conservation status of the new species, which faces several environmental impacts in the upper Rio Iguaçu basin. [ABSTRACT FROM AUTHOR]

Endemic to the south‐west Atlantic Ocean, the shortnose guitarfish (Zapteryx brevirostris) is a small species, classified as endangered by the IUCN. Although reproduction in captivity has been successful for some species, a range of factors can limit the success of captive breeding programmes for elasmobranchs. In Brazil, the Ubatuba Aquarium was the first public aquarium to reproduce small‐sized elasmobranchs. Since 2018, at least five parturition events have been recorded for Z. brevirostris at the institution. From a total of 13 live neonates that rearing was attempted, the mean ± standard error of weight, total length (TL) and disc width at birth were 17.47 ± 1.6 g, 13.25 ± 0.7 cm and 6.53 ± 0.2 cm, respectively. The mean weight as well as mean TL were higher for females at all births, with 26.15 g and 15.07 cm for females in comparison with 17.09 g and 13.94 cm for males. Considering the increasing risk of extinction that the species is facing, age and growth studies are fundamental for the success of conservation, improving the knowledge of Z. brevirostris life cycle so that a more efficient and sustainable management can be carried out. This study provides important data, as well as directions for captive breeding of the species. [ABSTRACT FROM AUTHOR]

The bentfin devil ray (Mobula thurstoni) is a migratory elasmobranch species with a wide distribution range. Despite the recent increase in mobulid research, critical habitats and home ranges are still being identified for these threatened species. In the present study, photo and video records opportunistically gathered by SCUBA diving effort were used to identify individuals and habitat usage by M. thurstoni in a marine protected area in the western equatorial Atlantic Ocean, Fernando de Noronha Archipelago (FNA). The bentfin devil ray was identified in five distinct records, in different years and sites around the archipelago. All the males showed developed claspers, suggesting mature individuals using the area. The UNESCO heritage site of FNA is considered an area of high biological importance, containing essential habitats for several species of fish, turtles and marine mammals. However, habitat usage by devil ray species is poorly reported in the region; therefore, the present study presents the first report of M. thurstoni at FNA, which adds the fifth mobulid ray species recorded in the region. Additionally, these results correspond to the second record of living specimens of M. thurstoni in Brazilian jurisdictional waters, highlighting new information on the species' distribution and the home range of mobulids in Brazil. [ABSTRACT FROM AUTHOR]

South Brazil's archaeological coastal sites (shellmounds and middens) show a diverse collection of shark faunal remains, some of which belong to species considered rare nowadays for the region. However, shark archaeological remains identification in this region has been historically insufficient and prone to mistakes. This study identified shark fauna and estimated body size (total length) present at two archaeological sites: Rio do Meio (1220‐977 Cal B.P.) and Enseada II (4286‐3783 Cal B.P.), located in Santa Catarina, South of Brazil. Here, 1600 teeth and 3588 vertebrae were analysed and identified. We showed higher historical shark species richness than previously reported for South Brazil in historical and archaeological studies. In total, we identified at least 15 species of sharks (11 species and four identifications at the genus level). The presence of juvenile shark remains adds to the evidence of pre‐colonial fishing impacts in local shark populations. The consistent recovery of adults and juveniles of Carcharias taurus points to a possible nursery area on the mouth of Babitonga bay. The high teeth frequency (43%) of C. taurus suggests the South Brazil coastline was once home to abundant populations of this critically endangered species. Furthermore, we discuss the presence of rare species nowadays, suggesting a possible historical residency for adult populations of Carcharodon carcharias based on the presence of juveniles and young‐of‐the‐year on archaeological sites. The occurrence of Negaprion brevirostris, a tropical species, might have been facilitated by ocean current variations. [ABSTRACT FROM AUTHOR]

Tracking fish consumption could provide additional information on changes to fish stocks, one of the planet's main protein sources. We used data on seafood consumption in fishing villages in Brazil over time to test for changes in: species richness, diversity, and composition, fish size and trophic levels, consumption of endangered species, and functional diversity (namely, species with different behavioral and habitat preferences). Our results demonstrate the potential to include this additional data source to complement fisheries data, especially in data-poor countries. With respect to Brazil specifically, we identified a decrease in both the average trophic level and size of the species consumed. While the consumption of endangered species had always been low, most of these species changed over time, thereby suggesting that many, especially elasmobranchs, may have become rare on the plates. Although it may be hard to fully isolate cultural changes from biodiversity changes when it comes to analyzing consumption data, by examining diets it is possible to identify aspects worth investigating further, such as, whether the decrease in dietary trophic levels mirrors a decrease in environmental trophic levels. In places where fisheries data are either inexistent or limited, diet track surveys, such as household expenditure programs, can help trace the changes caused by fisheries in stocks and habitats. [ABSTRACT FROM AUTHOR]

The illegal sale of endangered elasmobranchs has been recorded in a number of different Brazilian states, where sharks and rays are being marketed primarily as 'cação' or 'viola'. Brazil is ranked among the top 10 nations worldwide that harvest most sharks, causing an immeasurable impact on the local elasmobranch populations.The present study applied the DNA barcoding technique, based on the cytochrome C oxidase subunit I gene, for the molecular identification of the elasmobranch species sold as processed products under the generic names of 'cação', 'mangona', 'azul', 'cambeva', 'fiuso' and 'lombo preto', in the fish market of the city of Florianópolis, capital of the state of Santa Catarina, Brazil.Nine elasmobranch species were identified in the 56 samples analysed, including six sharks and three rays, representing six families, the Carcharhinidae, Sphyrnidae, Squatinidae, Arhynchobatidae, Myliobatidae and Gymnuridae. Prionace glauca, identified in more than half (56%) of the samples analysed, is listed as Near Threatened by the International Union for the Conservation of Nature.Six species identified in the present study, Sphyrna zygaena, Sphyrna lewini, Squatina guggenheim, Carcharhinus signatus, Gymnura altavela and Rioraja agassizii, are under some level of risk of extinction, while two others (Rhizoprionodon lalandii and Myliobatis goodei) are listed as Data Deficient.Our results indicate that the commercial exploitation of endemic sharks and rays at risk of extinction is commonplace in southern Brazil. This reinforces the need for more systematic monitoring of the trade in fishery products and more effective application of the environmental legislation and conservation programmes. [ABSTRACT FROM AUTHOR]

Ray species have been globally threatened due to high fishing pressure and habitat loss. In southern Brazil fisheries, despite many ray species are protected by law and usually non-targeted species, they are captured along with commercially important species. However, as in all of Brazil, there is evidence that rays are consumed, that is, there is a demand for meat from these animals, which intensifies the risk of extinction. Marine ethnobiology is an alternative approach to better understand these organisms, considering the traditional empirical knowledge of fishers and local communities. Our objective is to evaluate the knowledge of local residents, fishers, and tourists about the occurrence, distribution, reproduction, and feeding of ray species and also ray consumption among them. We hypothesized that fishers and locals have a deeper ecological knowledge about rays than tourists, and fishers should know more than residents. Individual interviews were conducted for three consecutive days at Armação beach, Florianópolis, Brazil. We asked people about ray biology and ecology based on questionnaires. Each respondent was categorized into three groups: fishers, locals, and tourists; and ranked according to an index of ecological knowledge of rays. The fishers had greater knowledge about rays, followed by residents and tourists. Additionally, fishers and locals consume rays, even the trade is prohibited locally, evidencing the need for legal enforcement. The fishers' knowledge may be essential for management of fish stocks, contributing to sustainable fishing and species conservation. In contrast, the tourists' lack of knowledge evidences the need to raise awareness of these animals. [ABSTRACT FROM AUTHOR]

Today, elasmobranchs are one the most threatened vertebrate groups worldwide. In fact, at least 90% of elasmobranch species are listed in the International Union for Conservation of Nature (IUCN) Red List, while more than 40% are data-deficient. Although these vertebrates are mainly affected by unsustainable fishery activities, bycatch is also one of the major threats to sharks and batoids worldwide, and represents a challenge for both sustainable fishery management and for biodiversity and conservational efforts. Thus, in this study, DNA barcode methodology was used to identify the bycatch composition of batoid species from small-scale industrial fisheries in the southwest Atlantic and artisanal fisheries from southeast Brazil. A total of 228 individuals belonging to four Chondrichthyes orders, seven families, and at least 17 distinct batoid species were sequenced; among these individuals, 131 belonged to species protected in Brazil, 101 to globally threatened species, and some to species with trade restrictions provided by Appendix II of the Convention on International Trade in Endangered Species (CITES). These results highlight the impacts on marine biodiversity of bycatch by small-scale industrial and unmanaged artisanal fisheries from the southwest Atlantic, and support the implementation of DNA-based methodologies for species-specific identification in data-poor fisheries as a powerful tool for improving the quality of fisheries' catch statistics and for keeping precise bycatch records. [ABSTRACT FROM AUTHOR]