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.
‘We advise the authors to find a native English speaker to proofread the manuscript’. This is a standard feedback journals give to non-native English speakers. Journals are justifiably concerned with grammar but do not show the same rigour about another step crucial to biological research: specimen identification. Surveying the author guidelines of 100 journals, we found that only 6% of them request explicitly citation of the literature used in specimen identification. Authors hamper readers from contesting specimen identification whenever vouchers, identification methods, and taxon concepts are not provided. However, unclear taxonomic procedures violate the basic scientific principle of reproducibility. The scientific community must continuously look for practical alternatives to improve taxonomic identification and taxonomic verification. We argue that voucher pictures are an accessible, cheap and time-effective alternative to mitigate (not abolish) bad taxonomy by exposing preventable misidentifications. Voucher pictures allow scientists to judge specimen identification actively, based on available data. The popularization of high-quality image devices, photo-identification technologies and computer vision algorithms yield accurate scientific photo-documentation, improving taxonomic procedures. Taxonomy is timeless, transversal and essential to most scientific disciplines in biological sciences. It is time to demand rigour in taxonomic identifications.
Accurate taxonomic identifications and species delimitations are a fundamental problem in biology. The complex taxonomy of Nematoda is primarily based on morphology, which is often dubious. DNA barcoding emerged as a handy tool to identify specimens and assess diversity, but its applications in Nematoda are incipient. We evaluated cytochrome c oxidase subunit I (cox1) efficiency as a DNA barcode for nematodes scrutinising 5,241 sequences retrieved from BOLD and GenBank. The samples included genera with medical, agricultural, or ecological relevance: Anguillicola, Caenorhabditis, Heterodera, Meloidogyne, Onchocerca, Strongyloides, and Trichinella. We assessed cox1 performance through barcode gap and Probability of Correct Identification (PCI) analyses, and estimated species richness through Automatic Barcode Gap Discovery (ABGD). Each genus presented distinct gap ranges, mirroring the evolutionary diversity within Nematoda. Thus, to survey the diversity of the phylum, a careful definition of thresholds for lower taxonomic levels should be considered. PCIs were around 70% for both databases, highlighting operational biases and challenges in nematode taxonomy. ABGD inferred higher richness than the taxonomic labels informed by databases. The prevalence of specimen misidentifications and dubious species delimitations emphasise the value of integrative approaches to nematode taxonomy and systematics. Overall, cox1 is a relevant tool for integrative taxonomy of nematodes.
Background Aggressive behaviors must be addressed in elementary schools. Massage and storytelling can be strategies to deal with aggression because both involve experience exchange and social interaction. Both can decrease stress and anxiety and increase self-esteem. Objective To evaluate the effect of two interventions (massage and storytelling) on aggressive behaviors and academic performance of elementary school children. Method Three groups (n = 35 children in each group) of the second grade participated (aged 6.5–8.1 years). One group received ten extra classes of massage (MG), another group received extra classes of storytelling (SG), and the control group received extra classes of random subjects (CG). Extra classes lasted for 50 minutes, once a week. Aggressive behaviors were recorded on diaries, by the teachers and the coordinator. The frequency of aggressive behaviors and the academic performance of MG, SG, and CG were observed for six months and the groups were compared. Findings ANOVAs evidenced that MG and SG, but not CG, showed a reduction in aggressive behaviors registered by the teachers and coordinator, after the intervention. Academic performance of MG and SC improved after the intervention (p < 0.05).
Pentatomomorpha (Hemiptera: Heteroptera) occurs worldwide with almost 19,000 species within six superfamilies. Their wide morphological, behavioral, and ecological diversity is remarkable, making them subject of basic and applied studies. The mitochondrial cytochrome c oxidase subunit I (cox1) proposed as a DNA barcode for Metazoa is used in species discovery and identification, relying on threshold values to split intra‐ and interspecific sequences and a comprehensive library to accurate identification. Here, we scanned all the pentatomomorphan cox1 sequences on Barcode of Life Data System library aiming to provide an overview of available data; verify barcoding gaps at generic level; infer individual empirical threshold values to distinguish congeneric species; and test efficiency of cox1 based on the Probability of Correct Identification (PCI) analysis. Our final dataset comprised 12,189 sequences, covering five superfamilies, 32 families, 460 genera, and 1068 species. The dataset abundance and composition were biased to families with economic importance, that is, Pentatomidae, Lygaeidae, Scutelleridae, Coreidae, and Rhyparochromidae. Barcode gaps were detected for most of the analyzed genera, reaffirming the efficiency of cox1 for Pentatomomorpha. We inferred threshold values for 131 genera and found a global PCI of 74.33%, suggesting that one out of four analyzed species suffer from operational biases or hide cryptic species. We brought examples to illustrate how cox1 can be used to flag inconsistencies, refine, and shed light onto future studies on Pentatomomorpha. We emphasize the efficiency of cox1 as DNA barcode for these true bugs, advocating for its combined use with, for example, morphology in integrative approaches.
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