Happy World Animal Day! Today is all about celebrating the incredible species roaming our planet and promoting action for animal rights and welfare.
To mark this special day, we have collected some of our favourite animals published across Pensoft’s journal portfolio.
1. The ‘cute but deadly’ velvet worm
The Tiputini velvet worm (Oroperipatus tiputini). Credit: Roberto José León.
Look at those adorable little legs!
Oroperipatus tiputini is a velvet worm that researchers published as a new species in Zoosystematics and Evolution. These invertebrates are known as “living fossils” because they evolved over 500 million years ago, long before the dinosaurs.
The Tiputini velvet worm (Oroperipatus tiputini) adult and juvenile.
Despite its friendly appearance, the Tiputini velvet worm is an accomplished hunter that shoots a sticky substance from a pair of glands near its face to trap its prey!
Some creatures look like they belong to an era long ago.
But this one has only just been discovered! Found near American Samoa at a depth of 300 m, Nautilus samoaensis was one of three new nautilius species published in ZooKeys in 2023.
Underwater photos of living Nautilus samoaensis.
Sadly, these enigmatic molluscs with beautiful shells are facing population decline, and even extinction, due to the activity of unregulated fisheries.
Any ideas why Neopalpa donaldtrumpi was given its name?
Found in California, Arizona, and some areas of Mexico, this species was named days before Donald J. Trump became the the 45th President of the United States of America.
Neopalpa donaldtrumpi.
Researcher Dr Vazrick Nazari hoped that the fame around the blonde-haired moth would raise awareness for the importance of further conservation efforts for the species’ fragile habitat.
We think this fish may have taken the advice “keep your chin up” a bit too literally.
The longnosed stargazer (Ichthyscopus lebeck) looks like this for good reason – it buries itself in sand, with just its eyes visible, and leaps upwards to ambush prey.
Blue is a rare colour in nature, which is a shame because this tarantula from Thailand looks spectacular. The stylish spider sports iridescent streaks of neon colour on its legs, back, and mouthparts.
Chilobrachys natanicharum was already known in the pet trade as the electric blue tarantula, but a study published ZooKeys finally confirmed it as a unique species.
Tailless whip scorpion (Phrynus whitei). Credit: Fugus Guy via WikiMedia Commons.
Sorry about this one.
Phrynus whitei is an amblypygid – an order of arachnids also known as whip spiders or tailless whip scorpions. Despite its unsettling appearance, it is generally calm around humans and is non-venomous.
While we have enjoyed collecting a few of our favourite species featured in Pensoft journals, it is important to remember the value of every animal, regardless of cuteness or weirdness.
By supporting research and action that aims to protect our planet’s species, we can continue to enjoy our planet’s bizarre biodiversity that never fails to surprise and delight. Happy World Animal Day!
Leading scholarly publisher Pensoft has announced a strategic collaboration with R Discovery, the AI-powered research discovery platform by Cactus Communications, a renowned science communications and technology company. This partnership aims to revolutionize the accessibility and discoverability of research articles published by Pensoft, making them more readily available on R Discovery to its over three million researchers across the globe.
R Discovery, acclaimed for its advanced algorithms and an extensive database boasting over 120 million scholarly articles, empowers researchers with intelligent search capabilities and personalized recommendations. Through its innovative Reading Feed feature, R Discovery delivers tailored suggestions in a format reminiscent of social media, identifying articles based on individual research interests. This not only saves time but also keeps researchers updated with the latest and most relevant studies in their field.
Open Science is much more than cost-free access to research output.
Lyubomir Penev
One of R Discovery’s standout features is its ability to provide paper summaries, audio readings, and language translation, enabling users to quickly assess a paper’s relevance and enhance their research reading experience significantly.
With over 2.5 million app downloads and upwards of 80 million journal articles featured, the R Discovery database is one of the largest scholarly content repositories.
“At Pensoft, we do realise that Open Science is much more than cost-free access to research outputs. It is also about easier discoverability and reusability, or, in other words, how likely it is for the reader to come across a particular scientific publication and, as a result, cite and build on those findings in his/her own studies. By feeding the content of our journals into R Discovery, we’re further facilitating the discoverability of the research done and shared by the authors who trust us with their work,” said ARPHA’s and Pensoft’s founder and CEO Prof. Lyubomir Penev.
Abhishek Goel, Co-Founder and CEO of Cactus Communications, commented on the collaboration, “We are delighted to work with Pensoft and offer researchers easy access to the publisher’s high-quality research articles on R Discovery. This is a milestone in our quest to support academia in advancing open science that can help researchers improve the world.”
So far, R Discovery has successfully established partnership with over 20 publishers, enhancing the platform’s extensive repository of scholarly content. By joining forces with R Discovery, Pensoft solidifies its dedication to making scholarly publications from its open-access, peer-reviewed journal portfolio easily discoverable and accessible.
Content from 20 Pensoft journals will now be automatically added to ResearchGate to reach the research network’s 25 million users. Each journal will also receive a dedicated profile.
ResearchGate, the professional network for researchers, and Pensoft today announced a new partnership that will see a set of Pensoft’s open access journals increase their reach and visibility through ResearchGate – increasing access and engagement with its 25 million researcher members.
As part of this new partnership, 20 journals published by Pensoft – including the publisher’s flagship titles ZooKeys, PhytoKeys, MycoKeys, Biodiversity Data Journal and Research Ideas and Outcomes (RIO Journal) amongst others – will now have their content automatically added to ResearchGate upon publication to benefit from enhanced visibility and discoverability through ResearchGate’s innovative Journal Home offering. These journals will all have dedicated profiles and be prominently represented on all associated article pages on ResearchGate, as well as all other relevant touch points throughout the network.
Journal Home provides a unique opportunity for Pensoft to connect its authors with their readers. The new journal profiles on ResearchGate will provide a central location for each journal, enabling researchers to learn more, discover new article content, and understand how, through their network, they are connected to the journal’s community of authors and editors. Authors of these journals additionally benefit from having their articles automatically added to their ResearchGate profile page, giving them access to metrics, including who is reading and citing their research. These rich insights will also enable Pensoft to build a deeper understanding of the communities engaging with its journals.
“Pensoft is delighted to be working with ResearchGate to provide an even greater service to our authors and readers. ResearchGate offers an innovative way for us to grow the reach and visibility of our content, while also giving us a way to better understand and engage our author and reader audiences.”
said Prof Lyubomir Penev, CEO and founder of Pensoft.
“We couldn’t be happier to see Pensoft embark on this new partnership with ResearchGate. Journal Home will not only enable Pensoft authors to build visibility for their work, but provide them and Pensoft with greater insights about the communities engaging with that research. I look forward to seeing this new collaboration develop”
said Sören Hofmayer, co-founder and Chief Strategy Officer at ResearchGate.
About ResearchGate:
ResearchGate is the professional network for researchers. Over 25 million researchers use researchgate.net to share and discover research, build their networks, and advance their careers. Based in Berlin, ResearchGate was founded in 2008. Its mission is to connect the world of science and make research open to all.
A recent update introduced to the CMSY methodology used to assess the status of fish stocks has proven to more accurately predict the catch that a population can support than highly valued data-intensive models.
In a paper published in the journal Acta Ichthyologica et Piscatoria, the international team of researchers that shaped the improved CMSY++ model noted that its results better correspond with what is, in reality, the highest catch that a fish stock can support in the long-term, given that environmental conditions do not change much.
Now powered by an artificial neural network that has been trained with catch and biomass data of 400 stocks to identify plausible ranges of the initial and final state of the stocks being assessed, CMSY++ allows managers and scientists to input only catch data to estimate how much fish is left in a given stock and how much fishing pressure can be applied.
Schematic representation of the surplus production model used by CMSY, with indication of impaired recruitment due to small stock size, where FMSY is reduced linearly with decline in biomass.
Maximum sustainable catches or yield (MSY) is a concept developed in the 1950s by US fisheries scientist M.B. Schaefer who proposed that if fishers left in the water a biomass equivalent to at least 50 per cent of the unexploited fish population, that is, of the biomass it had before being commercially exploited, then the highest possible catches could be sustained over time.
“By comparing the results of CMSY++ to models that are considered superior because they require large amounts of initial data inputs, such as the Fox surplus-production model and the Stock Synthesis (SS3) age-structured model, we noticed that these models badly overpredicted the catch that a population can support when previous overfishing has reduced it to a small fraction of its natural size, as is the case with most exploited fish populations in the world.”
Dr. Rainer Froese, lead author of the study and a senior scientist at the GEOMAR Helmholtz Centre for Ocean Research.
In other words, the model underlying the CMSY++ method fitted the observed data, while the predictions of the ‘gold standard’ models were too optimistic in estimating sustainable catches.
Examples of graphical output of CMSY++, here for European plaice (Pleuronectes platessa) in the eastern English Channel.
“These models tend to estimate the biomass required to produce maximum sustainable yields as less than half of unexploited biomass, which is lower than M.B. Schaefer originally proposed based on the widely observed S-shaped growth curve of unexploited populations or population size that the ecosystem would normally accommodate.
“This finding could explain the often-observed failure of fisheries managers to maintain or rebuild depleted stocks even when the predictions of the gold standard models were followed.”
Daniel Pauly, co-author of the study and principal investigator of the Sea Around Us initiative at the University of British Columbia.
Research article:
Froese R, Winker H, Coro G, Palomares MLD, Tsikliras AC, Dimarchopoulou D, Touloumis K, Demirel N, Vianna GMS, Scarcella G, Schijns R, Liang C, Pauly D (2023) New developments in the analysis of catch time series as the basis for fish stock assessments: The CMSY++ method. Acta Ichthyologica et Piscatoria 53: 173-189. https://doi.org/10.3897/aiep.53.e105910
Microplastics forming the disproportionate amount of plastic garbage, and catfish have become numerically dominant in some ecosystems thanks to their tolerance to pollution and anoxic environments.
Armored catfish (Pterygoplicthys spp.) and microplastics, as invasive species and emerging contaminants, respectively, represent two socio-environmental problems in the globalized world, since both have negative effects on faunistic communities and freshwater habitats, as well as on rural community fisheries and public health.
Non-native invasive species of armored catfish have become numerically dominant in some ecosystems, with efforts to eradicate them a seemingly endless task. Due to this, a possible scenario of biological homogenization in Mesoamerica can be expected, mainly given by the wide dispersion of the Pterygoplichthys species, added to the introduction of other non-native catfish species.
Photo: Miguel Ángel Salcedo. Drawing: Diana Ríos-Hernández.
The omnipresence of plastics in terrestrial and aquatic environments is caused by their excessive use and inadequate management of waste. The discarded plastics are fragmented, degraded, and dissolved by solar radiation, wind, and water, among other agents, to be incorporated into the food web in aquatic environments.
Microplastics found in the digestive tract of armed catfish (Pterygoplichthys spp.)
Both persist in the aquatic environment, microplastics forming the disproportionate amount of plastic garbage, and catfish thanks to their tolerance to pollution and anoxic environments, and their ability to survive for several hours breeding atmospheric oxygen. What is the relationship between the two? Microplastics, depending on their origin and composition, are sedimented in the wetlands, where they can be ingested by detritus feeders, such as armored catfish, mainly in areas where there is runoff or discharge of liquid waste.
In this context, we ask ourselves, can armored catfish be used as biomonitors of microplastics deposited in wetlands? Taking the above into consideration, the doctoral student Gabriela Angulo-Olmos under the guidance of the researchers Nicolás Álvarez-Pliego, Alberto J. Sánchez, Rosa Florido, Miguel Ángel Salcedo, Allan K. Cruz-Ramírez and Arturo Garrido Mora from the Laboratorio de Humedales, from the División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, decided to answer the aforementioned question based on the numerical dominance of armored catfish recorded in the aquatic ecosystems of the Metropolitan Area of Villahermosa (MAV) in the coastal plain of the Gulf of Mexico.
A) Study area; Metropolitan Area of Villahermosa. Map modified from INEGI (2021). B) La Pólvora lake (Satélite Airbus 2023).
The stomach contents of the specimens from a lake located in the MAV were reviewed and the results showed that all the specimens had consumed microfibers. This result corroborated that these organisms can ingest sedimented microplastics due to their benthophagous habits.
The use of armored catfish as a resource in the food industry has had positive results, but is still insufficient. Therefore, we propose that another option to control their populations is to subtract and use this organism to verify which are the most frequent and abundant emerging contaminants deposited in the bottoms of urban wetlands.
Research article:
Angulo-Olmos G, Alvarez-Pliego N, Sánchez AJ, Florido R, Salcedo MÁ, Garrido-Mora A, Cruz-Rámirez AK (2023) Microfibers in the gut of invasive armored catfish (Pterygoplichthys spp.) (Actinopterygii: Siluriformes: Loricariidae) in an urban lake in the floodplain of the Grijalva River basin, Mexico. Acta Ichthyologica et Piscatoria 53: 81–88. https://doi.org/10.3897/aiep.53.102643
Novel nanopublication workflows and templates for associations between organisms, taxa and their environment are the latest outcome of the collaboration between Knowledge Pixels and Pensoft.
Nanopublications complement human-created narratives of scientific knowledge with elementary, machine-actionable, simple and straightforward scientific statements that prompt sharing, finding, accessibility, citability and interoperability.
By making it easier to trace individual findings back to their origin and/or follow-up updates, nanopublications also help to better understand the provenance of scientific data.
With the nanopublication format and workflow, authors make sure that key scientific statements – the ones underpinning their research work – are efficiently communicated in both human-readable and machine-actionable mannerin line with FAIR principles. Thus, their contributions to science are better prepared for a reality driven by AI technology.
The machine-actionability of nanopublications is a standard due to each assertion comprising a subject, an object and a predicate (type of relation between the subject and the object), complemented by provenance, authorship and publication information. A unique feature here is that each of the elements is linked to an online resource, such as a controlled vocabulary, ontology or standards.
Now, what’s new?
As a result of the partnership between high-tech startup Knowledge Pixels and open-access scholarly publisher and technology provider Pensoft, authors in Biodiversity Data Journal (BDJ) can make use of three types of nanopublications:
Nanopublications associated with a manuscript submitted to BDJ. This workflow lets authors add a Nanopublications section within their manuscript while preparing their submission in the ARPHA Writing Tool (AWT). Basically, authors ‘highlight’ and ‘export’ key points from their papers as nanopublications to further ensure the FAIRness of the most important findings from their publications.
Standalone nanopublication related to any scientific publication, regardless of its author or source. This can be done via the Nanopublications page accessible from the BDJ website. The main advantage of standalone nanopublication is that straightforward scientific statements become available and FAIR early on, and remain ready to be added to a future scholarly paper.
Nanopublications as annotations to existing scientific publications. This feature is available from several journals published on the ARPHA Platform, including BDJ. By attaching an annotation to the entire paper (via the Nanopublication tab) or a text selection (by first adding an inline comment, then exporting it as a nanopublication), a reader can evaluate and record an opinion about any article using a simple template based on the Citation Typing Ontology (CiTO).
Nanopublications for biodiversity data?
At Biodiversity Data Journal (BDJ), authors can now incorporate nanopublications within their manuscripts to future-proofthe most important assertions on biological taxa and organisms or statements about associations of taxa or organisms and their environments.
On top of being shared and archived by means of a traditional research publication in an open-access peer-reviewed journal, scientific statements using the nanopublication format will also remain ‘at the fingertips’ of automated tools that may be the next to come looking for this information, while mining the Web.
Using the nanopublication workflows and templates available at BDJ, biodiversity researchers can share assertions, such as:
So far, the available biodiversity nanopublication templates cover a range of associations, including those between taxa and individual organisms, as well as between those and their environments and nucleotide sequences.
Nanopublication template customised for biodiversity research publications available from Nanodash.
As a result, those easy-to-digest ‘pixels of knowledge’ can capture and disseminate information about single observations, as well as higher taxonomic ranks.
The novel domain-specific publication format was launched as part of thecollaboration betweenKnowledge Pixels – an innovative startup tech company aiming to revolutionise scientific publishing and knowledge sharing and the open-access scholarly publisherPensoft.
Basically, a nanopublication – unlike a research article – is a tiny snippet of a precise and structured scientific finding (e.g. medication X treats disease Y), which exists as a reusable and cite-able pieces of a growing knowledge graph stored on a decentralised server network in a format that it is readable for humans, but also “understandable” and actionable for computers and their algorithms.
These semantic statements expressed in community-agreed terms, openly available through links to controlled vocabularies, ontologies and standards, are not only freely accessible to everyone in both human-readable and machine-actionable formats, but also easy-to-digest for computer algorithms and AI-powered assistants.
In short, nanopublications allow us to browse and aggregate such findings as part of a complex scientific knowledge graph. Therefore, nanopublications bring us one step closer to the next revolution in scientific publishing, which started with the emergence and increasing adoption of knowledge graphs.
“As pioneers in the semantic open access scientific publishing field for over a decade now, we at Pensoft are deeply engaged with making research work actually available at anyone’s fingertips. What once started as breaking down paywalls to research articles and adding the right hyperlinks in the right places, is time to be built upon,”
By letting computer algorithms access published research findings in a structured format, nanopublications allow for the knowledge snippets that they are intended to communicate to be fully understandable and actionable. With nanopublications, each of those fragmentsof scientific information is interconnected and traceable back to its author(s) and scientific evidence.
A nanopublication is a tiny snippet of a precise and structured scientific finding (e.g. medication X treats disease Y), which exists within a growing knowledge graph stored on a decentralised server network in a format that it is readable for humans, but also “understandable” and actionable for computers and their algorithms. Illustration by Knowledge Pixels.
By building on shared knowledge representation models, these data become Interoperable (as in the Iin FAIR), so that they can be delivered to the right user, at the right time, in the right place , ready to be reused (as per the R in FAIR) in new contexts.
Another issue nanopublications are designed to address is research scrutiny. Today, scientific publications are produced at an unprecedented rate that is unlikely to cease in the years to come, as scholarship embraces the dissemination of early research outputs, including preprints, accepted manuscripts and non-conventional papers.
A network of interlinked nanopublications could also provide a valuable forum for scientists to test, compare, complement and build on each other’s results and approaches to a common scientific problem, while retaining the record of their cooperation each step along the way.
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We encourage you to try the nanopublications workflow yourself when submitting your next biodiversity paper to Biodiversity Data Journal.
Community feedback on this pilot project and suggestions for additional biodiversity-related nanopublication templates are very welcome!
On the journal website: https://bdj.pensoft.net/, you can find more about the unique features and workflows provided by the Biodiversity Data Journal (BDJ), including innovative research paper formats (e.g. Data Paper, OMICS Data Paper, Software Description, R Package, Species Conservation Profiles, Alien Species Profile), expert-provided data audit for each data paper submission, automated data export and more.
Don’t forget to also sign up for the BDJ newsletter via the Email alert form on the journal’s homepage and follow it on Twitter and Facebook.
Earlier this year, Knowledge Pixels and Pensoft presented several routes for readers and researchers to contribute to research outputs – either produced by themselves or by others – through nanopublications generated through and visualised in Pensoft’s cross-disciplinary Research Ideas and Outcomes (RIO) journal, which uses the same nanopublication workflows.
All journals published by Pensoft – each using the publisher’s self-developed ARPHA Platform – provide extensive and transparent information about their costs and services in line with the Plan S principles.
In support of transparency and openness in scholarly publishing and academia, the scientific publisher and technology provider Pensoft joined the Journal Comparison Service (JCS) initiative by cOAlition S, an alliance of national funders and charitable bodies working to increase the volume of free-to-read research.
As a result, all journals published by Pensoft – each using the publisher’s self-developed ARPHA Platform – provide extensive and transparent information about their costs and services in line with the Plan S principles.
The JCS was launched to aid libraries and library consortia – the ones negotiating and participating in Open Access agreements with publishers – by providing them with everything they need to know in order to determine whether the prices charged by a certain journal are fair and corresponding to the quality of the service.
According to cOAlition S, an increasing number of libraries and library consortia from Europe, Africa, North America, and Australia have registered with the JCS over the past year since the launch of the portal in September 2021.
While access to the JCS is only open to librarians, individual researchers may also make use of the data provided by the participating publishers and their journals.
This is possible through an integration with the Journal Checker Tool, where researchers can simply enter the name of the journal of interest, their funder and affiliation (if applicable) to check whether the scholarly outlet complies with the Open Access policy of the author’s funder. A full list of all academic titles that provide data to the JCS is also publicly available. By being on the list means a journal and its publisher do not only support cOAlition S, but they also demonstrate that they stand for openness and transparency in scholarly publishing.
“We are delighted that Pensoft, along with a number of other publishers, have shared their price and service data through the Journal Comparison Service. Not only are such publishers demonstrating their commitment to open business models and cultures but are also helping to build understanding and trust within the research community.”
said Robert Kiley, Head of Strategy at cOAlition S.
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About cOAlition S:
On 4 September 2018, a group of national research funding organisations, with the support of the European Commission and the European Research Council (ERC), announced the launch of cOAlition S, an initiative to make full and immediate Open Access to research publications a reality. It is built around Plan S, which consists of one target and 10 principles. Read more on the cOAlition S website.
About Plan S:
Plan S is an initiative for Open Access publishing that was launched in September 2018. The plan is supported by cOAlition S, an international consortium of research funding and performing organisations. Plan S requires that, from 2021, scientific publications that result from research funded by public grants must be published in compliant Open Access journals or platforms. Read more on the cOAlition S website.
By the time authors – who have acknowledged third-party financial support in their research papers submitted to a journal using the Pensoft-developed publishing platform: ARPHA – open their inboxes to the congratulatory message that their work has just been published and made available to the wide world, a similar notification will have also reached their research funder.
This automated workflow is already in effect at all journals (co-)published by Pensoft and those published under their own imprint on the ARPHA Platform, as a result of the new partnership with the OA Switchboard: a community-driven initiative with the mission to serve as a central information exchange hub between stakeholders about open access publications, while making things simpler for everyone involved.
All the submitting author needs to do to ensure that their research funder receives a notification about the publication is to select the supporting agency or the scientific project (e.g. a project supported by Horizon Europe) in the manuscript submission form, using a handy drop-down menu. In either case, the message will be sent to the funding body as soon as the paper is published in the respective journal.
“At Pensoft, we are delighted to announce our integration with the OA Switchboard, as this workflow is yet another excellent practice in scholarly publishing that supports transparency in research. Needless to say, funding and financing are cornerstones in scientific work and scholarship, so it is equally important to ensure funding bodies are provided with full, prompt and convenient reports about their own input.”
comments Prof Lyubomir Penev, CEO and founder of Pensoft and ARPHA.
“Research funders are one of the three key stakeholder groups in OA Switchboard and are represented in our founding partners. They seek support in demonstrating the extent and impact of their research funding and delivering on their commitment to OA. It is great to see Pensoft has started their integration with OA Switchboard with a focus on this specific group, fulfilling an important need,”
adds Yvonne Campfens, Executive Director of the OA Switchboard.
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About the OA Switchboard:
A global not-for-profit and independent intermediary established in 2020, the OA Switchboard provides a central hub for research funders, institutions and publishers to exchange OA-related publication-level information. Connecting parties and systems, and streamlining communication and the neutral exchange of metadata, the OA Switchboard provides direct, indirect and community benefits: simplicity and transparency, collaboration and interoperability, and efficiency and cost-effectiveness.
About Pensoft:
Pensoft is an independent academic publishing company, well known worldwide for its novel cutting-edge publishing tools, workflows and methods for text and data publishing of journals, books and conference materials.
All journals (co-)published by Pensoft are hosted on Pensoft’s full-featured ARPHA Publishing Platform and published in a way that ensures their content is as FAIR as possible, meaning that it is effortlessly readable, discoverable, harvestable, citable and reusable by both humans and machines.
Somatic growth rate is a central life-history parameter, especially in species like fishes or invertebrates which grow throughout their lives. It is needed in conservation and fisheries management but it can sometimes be tricky to estimate.
A school of Jacks pass overhead at Viuda (Widow) dive site, in Coiba National Park, Panama, a UNESCO World Heritage site. Photo by LASZLO ILYES under a CC-BY 2.0 license.
Dr. Froese presents two new data-limited methods to estimate somatic growth from maximum length combined with either length or age at maturation or with maximum age. They are applicable to a wide range of species, sizes, and habitats. Using these new methods, growth parameter estimates were produced for the first time for 110 fish species.
“The growth estimates derived with the new methods presented in this study appear suitable for consideration and preliminary guidance in applications for conservation or management,” Dr. Froese points out in his study.
He goes on to suggest that journals accept growth estimates performed with the new methods as new knowledge, if they are the first for a given species.
In order to facilitate the conservation and management of natural resources, FishBase will continue to compile growth parameters, including results obtained with these new methods.
Research article:
Froese R (2022) Estimating somatic growth of fishes from maximum age or maturity. Acta Ichthyologica et Piscatoria 52(2): 125-133. https://doi.org/10.3897/aiep.52.80093
For the first time, scientists report a vampire fish attached to the body of an Amazonian thorny catfish. Very unusually, the candirus were attached close to the lateral bone plates, rather than the gills, where they are normally found. Since the hosts were not badly harmed, and the candirus apparently derived no food benefit, scientists believe this association is commensalistic rather than parasitic. The research is published in the open-access journal Acta Ichthyologica et Piscatoria.
Guest blog post by Chiara C. F. Lubich, André R. Martins, Carlos E. C. Freitas, Lawrence E. Hurd and Flávia K. Siqueira-Souza
The Amazon River Basin is home to about 15% of all freshwater fish species known to science, and an estimated 40% yet to be named. These include some of the most bizarre fishes: the vampire fishes, locally known as candiru, members of the catfish subfamily Vandelliinae.). They survive by attaching themselves to the bodies of other fish and sucking on their blood, hence their common name. Yet, it was only recently that we found out that one candiru species, belonging to the genus Paracanthopoma,seems to be making use of its host in quite a different way.
During a sampling study of freshwater fish fauna in a lake of the Demeni River Basin, a left bank tributary of the Negro River, we found candirus attached to the surface of the body of an Amazonian species of a thorny catfish. By the end of the survey, we had observed a total of twenty candirus attached to the outside of the bodies of nine larger Doras phlyzakion, one or two per host. Very unusually, the candirus were attached close to the lateral bone plates, rather than the gills, where these fish are normally found.
Location of the study: Demeni River, left bank tributary of Negro River, Amazonas State, Brazil.
As a result of these observations, we recently published the first record of a candiru attached to the body surface of an Amazonian thorny catfish in an article in the open-access scholarly journal Acta Ichthyologica et Piscatoria.
Vampire fish have long and robust snouts, with strong dentary teeth that help them stay attached to the epidermis of their host and feed on its blood. However, when we performed a macroscopic analysis of the stomach contents of the preserved Paracanthopoma specimens, we were surprised to find no coagulated blood, nor flesh, skin or mucus. This might indicate an interaction between parasite and host that is more benign than usually attributed to vampire fish.
Doras phlyzakion with vampire fish (Paracanthopoma sp.) fixed into its epidermis close to the bony plates of the lateral line. Arrows: areas with reddish wounds.
We believe the association between candiru and host in this case might be commensalistic (where one organism benefits from another without harming it), rather than parasitic, because the hosts were not badly harmed, and the candiru apparently derived no food benefit.
But what else would they seek on the back of Amazonian thorny catfish? One explanation could be that, since candirus are tiny and nearly transparent, they might be avoiding getting noticed by visual predators by riding on larger fish. Another hypothesis is that they could be using their big cousins to transport them over longer distances that they wouldn’t be able to cover themselves, eventually making it to safety or new food sources.
Research article:
Lubich CCF, Martins AR, Freitas CEC, Hurd LE, Siqueira-Souza FK (2021) A candiru, Paracanthopoma sp. (Siluriformes: Trichomycteridae), associated with a thorny catfish, Doras phlyzakion (Siluriformes: Doradidae), in a tributary of the middle Rio Negro, Brazilian Amazon. Acta Ichthyologica et Piscatoria 51(3): 241-244. https://doi.org/10.3897/aiep.51.e64324
