Fernanda Almerón,Aluna do PPG BAN, junto ao equipe liderada pelos professores Nelson Fagundes, da Universidade Federal do Rio Grande do Sul (UFRGS), e Victor Hugo Valiati, da Universidade do Vale do Rio do Sinos (Unisinos), publicaram recentemente um artigo que mostra que um número significativo de espécies de elasmobrânquios, atualmente superexplorado ou ameaçado por atividades pesqueiras, estão sendo comercializado no mercado interno brasileiro sob um nome popular comum: “cação”. O uso de tal nomenclatura é impreciso, sendo problemático para controlar os efeitos negativos do consumo de tubarões e informar o consumidor sobre as origens do produto. Este trabalho que usa como ferramenta a biologia molecular (DNA Barcoding) permitiu identificar, em nível de espécies as amostras de cação disponíveis nos mercados locais do sul do Brasil.

Resultados de este estúdio foram destacados na reportagem da Revista Super interesante. Em uma nota com o titulo:

Cação: a maior mentira da vitrine da peixaria

LINK: https://super.abril.com.br/ciencia/cacao-a-maior-mentira-da-vitrine-da-peixaria/

Cação: a maior mentira na vitrine da peixaria/iStock

Foto: https://sp.depositphotos.com/111692660/stock-photo-deception-concept-disguise-between-shark.html

O artigo original foi publicado na revista Frontiers in Genetics.

Molecular Identification of Shark Meat From Local Markets in Southern Brazil Based on DNA Barcoding: Evidence for Mislabeling and Trade of Endangered Species

Almerón-Souza Fernanda, Sperb Christian, Castilho Carolina L., Figueiredo Pedro I. C. C., Gonçalves Leonardo T., Machado Rodrigo, Oliveira Larissa R., Valiati Victor H., Fagundes Nelson J. R. (2018)

Abstract:

Elasmobranchs, the group of cartilaginous fishes that include sharks and rays, are especially vulnerable to overfishing due to low fecundity and late sexual maturation. A significant number of elasmobranch species are currently overexploited or threatened by fisheries activities. Additionally, several recent reports have indicated that there has been a reduction in regional elasmobranch population sizes. Brazil is an important player in elasmobranch fisheries and one of the largest importers of shark meat. However, carcasses entering the shark meat market have usually had their fins and head removed, which poses a challenge to reliable species identification based on the morphology of captured individuals. This is further complicated by the fact that the internal Brazilian market trades several different elasmobranch species under a common popular name: “cação.” The use of such imprecise nomenclature, even among governmental agencies, is problematic for both controlling the negative effects of shark consumption and informing the consumer about the origins of the product. In this study, we used DNA barcoding (mtDNA, COI gene) to identify, at the species level, “cação” samples available in local markets from Southern Brazil. We collected 63 samples traded as “cação,” which we found to correspond to 20 different species. These included two teleost species: Xiphias gladius (n = 1) and Genidens barbus (n = 6), and 18 species from seven elasmobranch orders (Carcharhiniformes, n = 42; Squaliformes, n = 3; Squatiniformes, n = 2; Rhinopristiformes, n = 4; Myliobatiformes, n = 3; Rajiformes, n = 1; and Torpediniformes, n = 1). The most common species in our sample were Prionace glauca (n = 15) and Sphyrna lewini(n = 14), while all other species were represented by four samples or less. Considering IUCN criteria, 47% of the elasmobranch species found are threatened at the global level, while 53% are threatened and 47% are critically endangered in Brazil. These results underline that labeling the meat of any shark species as “cação” is problematic for monitoring catch allocations from the fishing industry and discourages consumer engagement in conservationist practices through informed decision-making.

Link: https://www.frontiersin.org/articles/10.3389/fgene.2018.00138/full

Elizabeth Kathleen de Queiroz Rodrigues apresentou na última terça-feira, dia 05 de junho, sua Dissertação:

TAXONOMIA INTEGRATIVA DO GÊNERO  MINIATURA Odontocharacidium (CHARACIFORMES: CRENUCHIDAE)

A banca esteve constituída pelo

                                                  Dr. Luiz R. Malabarba (UFRGS)

                                                  Dr. Claudio Oliveira, (Unesp)

                                                  Dr. Paulo Andreas Buckup (UFRJ)

                                                  Dr. Guilherme Dutra (UFPA)

                                                  Dr. Alexandre Aleixo Padovan (UFPA)

                                         Orientado pelo Prof. Dr. André Luiz Netto Ferreira (UFRGS)

                                         Co-orientador Dr. Marcelo José Sturaro (UFPA)

E. W. Wendt, C. M. Monteiro, S. B. Amato

Abstract

Structure of the helminth community of Megaleporinus obtusidens collected in Lake Guaíba was evaluated, and the results indicated that the diversity of helminth species was probably determined by fish behavior and eating habits. The influence of sex, weight, and standard length of hosts for parasitic indices was also analyzed. Sixteen helminth species were found parasitizing M. obtusidens, including the following: platyhelminths, with the highest richness, represented by one species of Aspidobothrea; four species of Digenea; and eight species of Monogenea; the latter, presented the highest prevalence. Rhinoxenus arietinus, found in nasal cavities, had the greater abundance, and was the only species classified as core. The prevalence of Urocleidoides paradoxus was significantly influenced by the sex of the host; females had the highest values. Abundance was weakly influenced by fish weight and the body length of the hosts. Urocleidoides sp. had its abundance weakly influenced by the host weight. The other helminths were not influenced by biometric characteristics of the hosts. The total species richness was similar between male and female fish, and both had 14 helminth species of parasites.

LINK: https://link.springer.com/article/10.1007/s00436-018-5933-4

JULIANA M. WINGERT, JUNIOR CHUCTAYA  & LUIZ R. MALABARBA

Resumo

Uma nova espécie de Bryconops é descrita do alto rio Juruena, bacia do rio Tapajós na bacia amazônica, estado de Mato Grosso, Brasil. A nova espécie pertence ao subgênero Creatochanes por apresentar a extremidade posterior da maxila atingindo a junção do segundo e terceiro infraorbitais, e margem posteroventral do segundo infraorbital formando uma borda completa com terceiro infraorbital, sem área nua entre eles. A nova espécie é facilmente distinguida das outras espécies do subgênero Creatochanes pelo padrão de colorido da nadadeira caudal, com o lobo dorsal preto, pigmentado na metade distal e o lobo ventral cinza escuro ao longo de sua porção ventral, abaixo da horizontal formada pela margem ventral do pedúnculo caudal.

LINK: https://biotaxa.org/Zootaxa/article/view/zootaxa.4418.4.4

FIGURE . Coloration in life of Bryconops sapezal. Rio Juruena, Rio Tapajós basin, Mato Grosso State, Brazil. Photo: Rodrigo J. Ilário. Scale bar = 10 mm.

Mayara Pereira Neves, João Paulo de Arruda Amorim, Rosilene Luciana Delariva

Abstract

This study aimed to evaluate the histopathological biomarkers of the gills and liver of endemic catfish to test the hypothesis that, in environments under intense land use by agricultural activities, histopathological alterations occur more severely. Samples were collected by electrofishing in seven streams in the Lower Iguaçu basin quarterly from August 2015 to February 2016. The gills and livers were processed according to routine histological methods and examined by light microscopy. The histopathological alterations observed in fish from the streams with a higher percentage of natural vegetation cover were considered modest and indicated normal functioning of the organ (such as edema, hyperplasia, and leukocyte infiltration). As predicted, fish collected in streams with higher agricultural influence presented moderate to severe damage (aneurysm, vacuolization and cytoplasmic degeneration, and pyknotic nucleus). The abundance of chloride cells was significantly increased in the gills of Ancistrus mullerae collected in rural streams. In addition, in most streams, mucous cells were more abundant during the rainy period. Significant differences were observed in the histopathological index (HI) of the gills and livers, where severe histopathological alterations occurred in fish from streams with a higher agricultural influence. The observed alterations were more severe in the liver than in the gills, which are indeed related to the liver’s key role in the detoxification of xenobiotics. We conclude that more severe histological alterations occurred in fish from streams with the highest land use by agricultural activities. Thus, our work provides important insight into the conservation and management of natural resources.

LINK: https://link.springer.com/article/10.1007%2Fs11356-018-1283-0

Fig. 4 Sections of hepatic tissue of A. mullerae sampled in streams with different land uses belonging to the Lower River Iguaçu basin, Brazil, during the dry and rainy period/2015–2016. a Normal hepatocytes and blood vessel (bv) in forest stream (F1). b Vascular congestion (asterisk) and melanomacrophage aggregates (arrowhead) in forest stream (F2). c. Leukocyte infiltration (arrow) in forest stream (F1). d Normal nucleus (arrowhead) and nuclear hypertrophy (arrow) in rural stream (R1). e Cytoplasmic vacuolization with nucleus in lateral position in rural stream (R3). f Pyknotic nucleus (arrowhead) in rural stream (R2). Harris’s hematoxylin and eosin (HE)

Tiago P.Carvalho,  Mariangeles Arce H. Roberto E.Reis Mark H.Sabaj

Abstract

LINK: https://www.sciencedirect.com/science/article/pii/S1055790317305870

C.M. Monteiro, E.W. Wendt  and Y.D. Zebral

Abstract

A new species of Dendrorchis is described and compared with others in the genus. The parasites were found in the swim bladder of the annual killifish Cynopoecilus melanotaenia. Hosts were collected from a seasonal wetland in southern Brazil. The main characteristics of D. pampae are: genital pore in the intestinal bifurcation region elongate and lobed vitellaria uterine loops limited to the acetabular region and to the rear end of the body; and wide intestinal caeca. An emended diagnosis of the genus Dendrorchis includes the characteristics of the new species. This is the first record of an adult digenean in an annual killifish from South America.

Link: https://www.cambridge.org/core/journals/journal-of-helminthology/article/dendrorchis-pampae-sp-n-digenea-gorgoderidae-from-cynopoecilus-melanotaenia-cyprinodontiformes-cynolebiidae-a-killifish-from-southern-brazil-with-an-emended-diagnosis-of-dendrorchis/B1CC887CA02C88E4C2C35A5492D56F94

FIGURE Dendrorchis pampae n. sp. from the swim bladder of the killifish Cynopoecilus melanotaenia: (A) in toto (ventral view, composite); (B) anterior region, with the cirrus pouch in detail.

M. C. Andrade, M. Jégu P. A. Buckup A. L. Netto‐Ferreira (2018)

Abstract

FIGURE: Myleus pachyodus sp. nov., Rio Tapajós basin, MNRJ 35023, holotype, female, 198.0 mm standard length

FIGURE. Left premaxilla ofMyleus pachyodussp. nov. in ventral view, MZUSP 95477, paratype, skeleton180·0 mm standard length. 1–5, outer teeth row; 1–2, inner teeth row