761 research outputs found

    Transcriptomic Analysis of Four Cerianthid (Cnidaria, Ceriantharia) Venoms

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    This work is licensed under a Creative Commons Attribution 4.0 International License.Tube anemones, or cerianthids, are a phylogenetically informative group of cnidarians with complex life histories, including a pelagic larval stage and tube-dwelling adult stage, both known to utilize venom in stinging-cell rich tentacles. Cnidarians are an entirely venomous group that utilize their proteinaceous-dominated toxins to capture prey and defend against predators, in addition to several other ecological functions, including intraspecific interactions. At present there are no studies describing the venom for any species within cerianthids. Given their unique development, ecology, and distinct phylogenetic-placement within Cnidaria, our objective is to evaluate the venom-like gene diversity of four species of cerianthids from newly collected transcriptomic data. We identified 525 venom-like genes between all four species. The venom-gene profile for each species was dominated by enzymatic protein and peptide families, which is consistent with previous findings in other cnidarian venoms. However, we found few toxins that are typical of sea anemones and corals, and furthermore, three of the four species express toxin-like genes closely related to potent pore-forming toxins in box jellyfish. Our study is the first to provide a survey of the putative venom composition of cerianthids and contributes to our general understanding of the diversity of cnidarian toxins.SĂŁo Paulo Research Foundation FAPESP 2015/24408-42017/50028-0 (SPRINT)2019/03552-0CNPq (PROTAX) 440539/2015-3CNPq (Research Productivity Scholarship)301293/2019-

    First Record Along The Uruguayan Coast Of The Largest Sea Nettle Jellyfish, Chrysaora Plocamia (lesson, 1830) (cnidaria: Scyphozoa)

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    Chrysaora plocamia is one of the 15 species of the jellyfish genus Chrysaora. This species has an unusualdistribution pattern, occurring on both Atlantic and Pacific coasts of South America. It is distributed along the southeastern Pacific Ocean, encompassing coastal areas of Peru and Chile, and reaching the Patagonian coast of Argentina in the southwestern Atlantic. During two separate events, two large specimens of Chrysaora were collected on the east coast of Uruguay at La Paloma. Based on morphology and molecular data, these specimens were identified as Chrysaora plocamia. These records are described along with oceanographic features observed at that time. Unusual oceanographic and atmospheric conditions may explain the presence of these specimens 1,100 km north of the current northernmost known distribution. © 2016 Check List and Authors.12

    Morphology is not always useful for diagnosis, and that’s ok: Species hypotheses should not be bound to a class of data. Reply to Brown and Gibbons (S Afr J Sci. 2022;118(9/10), Art. #12590)

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    This paper serves as a reply to the Commentary by Brown and Gibbons (S Afr J Sci. 2022;118(9/10), Art. #12590) on our recently published paper on systematics of the moon jellyfish genus Aurelia (Lawley et al. PeerJ 2021;9, e11954)). We emphasise that we are not advocating for the routine use of molecular data alone in taxonomic diagnoses, rather that it is a valid approach in cases where, after detailed analyses, morphological features are shown to be unreliable

    Protective Effects of Walnut Extract Against Amyloid Beta Peptide-Induced Cell Death and Oxidative Stress in PC12 Cells

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    Amyloid beta-protein (AÎČ) is the major component of senile plaques and cerebrovascular amyloid deposits in individuals with Alzheimer’s disease. AÎČ is known to increase free radical production in neuronal cells, leading to oxidative stress and cell death. Recently, considerable attention has been focused on dietary antioxidants that are able to scavenge reactive oxygen species (ROS), thereby offering protection against oxidative stress. Walnuts are rich in components that have anti-oxidant and anti-inflammatory properties. The inhibition of in vitro fibrillization of synthetic AÎČ, and solubilization of preformed fibrillar AÎČ by walnut extract was previously reported. The present study was designed to investigate whether walnut extract can protect against AÎČ-induced oxidative damage and cytotoxicity. The effect of walnut extract on AÎČ-induced cellular damage, ROS generation and apoptosis in PC12 pheochromocytoma cells was studied. Walnut extract reduced AÎČ-mediated cell death assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reduction, and release of lactate dehydrogenase (membrane damage), DNA damage (apoptosis) and generation of ROS in a concentration-dependent manner. These results suggest that walnut extract can counteract AÎČ-induced oxidative stress and associated cell death

    The Role of Turtles as Coral Reef Macroherbivores

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    Herbivory is widely accepted as a vital function on coral reefs. To date, the majority of studies examining herbivory in coral reef environments have focused on the roles of fishes and/or urchins, with relatively few studies considering the potential role of macroherbivores in reef processes. Here, we introduce evidence that highlights the potential role of marine turtles as herbivores on coral reefs. While conducting experimental habitat manipulations to assess the roles of herbivorous reef fishes we observed green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) showing responses that were remarkably similar to those of herbivorous fishes. Reducing the sediment load of the epilithic algal matrix on a coral reef resulted in a forty-fold increase in grazing by green turtles. Hawksbill turtles were also observed to browse transplanted thalli of the macroalga Sargassum swartzii in a coral reef environment. These responses not only show strong parallels to herbivorous reef fishes, but also highlight that marine turtles actively, and intentionally, remove algae from coral reefs. When considering the size and potential historical abundance of marine turtles we suggest that these potentially valuable herbivores may have been lost from many coral reefs before their true importance was understood

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    CatĂĄlogo TaxonĂŽmico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

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    The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the CatĂĄlogo TaxonĂŽmico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others
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