30,002 results match your criteria trophic


Reef communities show predictable undulations in linear abundance size spectra from copepods to sharks.

Ecol Lett 2021 Jul 21. Epub 2021 Jul 21.

Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia.

Among the more widely accepted general hypotheses in ecology is that community relationships between abundance and body size follow a log-linear size spectrum, from the smallest consumers to the largest predators (i.e. 'bacteria to whales'). Read More

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Chloroacetanilide herbicide-induced rat enterochromaffin cell tumors: a case study within the context of the IPCS framework, for analyzing the relevance of a cancer mode of action for humans.

Authors:
Midori Yoshida

J Toxicol Pathol 2021 Jul 2;34(3):213-222. Epub 2021 Apr 2.

Food Safety Commission, Cabinet Office of Japan, Akasaka Park Bld 22F, 5-2-20 Akasaka, Minato-ku, Tokyo 107-6122, Japan.

The WHO International Programme on Chemical Safety (IPCS) framework for analyzing the relevance of a cancer mode of action (MoA) for humans (IPCS cancer-HRF) is an application to assess human relevance of tumorigenic hazards found through rodent bioassays. The chloroacetanilide herbicides, butachlor and alachlor, induced enterochromaffin-like (ECL) cell tumors in rat stomachs, at the highest doses. This study analyzed the human relevance of this tumor by applying the IPCS cancer-HRF using published data. Read More

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A non-invasive assessment of essential trace element utilization at different trophic levels in African wildlife.

J Environ Manage 2021 Sep 9;293:112820. Epub 2021 Jun 9.

Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa.

The complex relationships that exist between terrestrial mammals and their habitats make African ecosystems highly interactive environments. Anthropogenic activities including climate change have altered geochemical cycles, which influence nutrient availability and deficiency at local, regional and global scales. As synergistic and antagonistic interactions occur between essential elements at both deficiency and excess concentrations, the differences in feeding strategy between trophically distinct groups of terrestrial vertebrates are likely to influence the degree to which overall nutrient needs are met or may be deficient. Read More

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September 2021

As the Arctic becomes boreal: ongoing shifts in a high-Arctic seabird community.

Ecology 2021 Jul 21:e03485. Epub 2021 Jul 21.

Norwegian Polar Institute, Fram Centre, 9296, Tromsø, Norway.

The Arctic is currently experiencing the most rapid warming on Earth. Arctic species communities are expected to be restructured with species adapted to warmer conditions spreading poleward and, if already present, becoming more abundant. We tested this prediction using long-term monitoring data (2009-2018) from nine of the most common seabird species breeding in the High Arctic Svalbard archipelago. Read More

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On the sensitivity of food webs to multiple stressors.

Ecol Lett 2021 Jul 19. Epub 2021 Jul 19.

Département de biologie, Université de Sherbrooke, Sherbrooke, QC, Canada.

Evaluating the effects of multiple stressors on ecosystems is becoming increasingly vital with global changes. The role of species interactions in propagating the effects of stressors, although widely acknowledged, has yet to be formally explored. Here, we conceptualise how stressors propagate through food webs and explore how they affect simulated three-species motifs and food webs of the Canadian St. Read More

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When a Tritrophic Interaction Goes Wrong to the Third Level: Xanthoxylin From Trees Causes the Honeybee Larval Mortality in Colonies Affected by the River Disease.

J Chem Ecol 2021 Jul 21. Epub 2021 Jul 21.

Sección Etología, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.

The "River Disease" (RD), a disorder impacting honeybee colonies located close to waterways with abundant riparian vegetation (including Sebastiania schottiana, Euphorbiaceae), kills newly hatched larvae. Forager bees from RD-affected colonies collect honeydew excretions from Epormenis cestri (Hemiptera: Flatidae), a planthopper feeding on trees of S. schottiana. Read More

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Influence of the chlorophyll-a gradient on the community structure of plankton microcrustaceans (Cladocera and Copepoda) in a Neotropical reservoir.

An Acad Bras Cienc 2021 19;93(2):e20190379. Epub 2021 Jul 19.

Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais (PEA), Universidade Estadual de Maringá (UEM), Núcleo de Pesquisas em Limnologia Ictiologia e Aquicultura (Nupélia), Av. Colombo, 5790, Campus Universitário, 87020-900 Maringá, PR, Brazil.

Fish farming in net cages is considered as an alternative to food production in response to elevated population growth, and zooplankton is an important resource to the development of this economic activity. We (i) compared microcrustacean composition in eutrophic and oligotrophic habitats under net tank influence, (ii) investigated changes in species distributions in these habitats, and (iii) indicated which chlorophyll-a concentrations presented thresholds that alter community structure. We expected different responses of species to changes in chlorophyll-a concentration due to net cage management, as chlorophyll-a represents an estimate of food availability. Read More

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Nutrient dynamics and budgeting in a semi-enclosed coastal hypersaline lagoon.

Environ Sci Pollut Res Int 2021 Jul 20. Epub 2021 Jul 20.

National Centre for Coastal Research, Ministry of Earth Sciences, NIOT Campus, Chennai, Tamil Nadu, 600100, India.

Biogeochemical and ecological responses to limited external nutrient loading are poorly understood in tropical semi-enclosed coastal lagoons which are highly influenced by hydrological and salinity regimes. With objectives towards ecosystem sustainability via better management of the nutrient inputs, investigations were carried out to estimate the water, salt, and nutrient budget of "Pulicat" hypersaline coastal lagoon for the year 2018-2019. The budget revealed that the annual rate of precipitation and evaporation are the major driving factors regulating the annual residual flow in the lagoon. Read More

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Stable isotopes and community surveys reveal differential use of artificial and natural reefs by South Florida fishes.

Heliyon 2021 Jul 26;7(7):e07413. Epub 2021 Jun 26.

Department of Marine and Environmental Sciences, Halmos College of Arts and Sciences, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, FL 33004 USA.

Artificial reefs may enhance the biological production of reef-associated flora and fauna, but their trophic structure relative to that of natural reefs remains understudied. We assessed trophic relationships by 1) comparing reef fish communities and 2) comparing δC and δN in 43 fish species from both artificial reef sites and adjacent natural reef tracts in Broward County, Florida. We tested the effect of sampling location (artificial, first, and second reef), general feeding strategy (herbivore, omnivore, invertivore, and carnivore), phylogeny, and standard length on δC and δN. Read More

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Identification of enriched hyperthermophilic microbial communities from a deep-sea hydrothermal vent chimney under electrolithoautotrophic culture conditions.

Sci Rep 2021 Jul 20;11(1):14782. Epub 2021 Jul 20.

Aix Marseille Université, Université de Toulon, IRD, CNRS, MIO UM 110, 13288, Marseille Cedex 09, France.

Deep-sea hydrothermal vents are extreme and complex ecosystems based on a trophic chain. We are still unsure of the identities of the first colonizers of these environments and their metabolism, but they are thought to be (hyper)thermophilic autotrophs. Here we investigate whether the electric potential observed across hydrothermal chimneys could serve as an energy source for these first colonizers. Read More

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Simultaneous treatment with pentoxifylline does not adversely affect the neurotrophic effects of brain-derived neurotrophic factor on spiral ganglion neurons.

Neuroreport 2021 Jul 19. Epub 2021 Jul 19.

Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.

The hemorheologic drug pentoxifylline is applied for the treatment of sudden sensorineural hearing loss and tinnitus to improve cochlear microcirculation. Recent studies also suggest protective and trophic effects on neuronal cells. Because the preservation of sensorineural structures of the inner ear is fundamental for normal hearing and hearing restoration with auditory prostheses, pentoxifylline and neurotrophic factors such as brain-derived neurotrophic factor (BDNF) are promising candidates to treat degenerative disorders of the inner ear. Read More

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Deoxygenation reduces growth rates and increases assimilation of essential trace metals in gilthead seabream (Sparus aurata).

Environ Pollut 2021 Jul 13;288:117786. Epub 2021 Jul 13.

International Atomic Energy Agency, 4a Quai Antoine 1er, 98000, Monaco.

The widespread decline in oceanic dissolved oxygen (DO), known as deoxygenation, is a threat to many marine ecosystems, and fish are considered one of the more vulnerable marine organisms. While food intake and growth rates in some fish can be reduced under hypoxic conditions (DO ~ 60 μmol kg), the dietary transfer of essential metals remains unclear. In this context, we investigated the influence of DO on the dietary acquisition of two essential metals (Zn and Mn) in the commercially important gilthead seabream (Sparus aurata) using radiotracer techniques. Read More

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Blood meal analysis: host-feeding patterns of biting midges (Diptera, Ceratopogonidae, Culicoides Latreille) in Slovakia.

Parasite 2021 20;28:58. Epub 2021 Jul 20.

Department of Epizootiology, Parasitology and Protection of One Health, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041 81 Košice, Slovak Republic.

Biting midges of the genus Culicoides are vectors of important pathogens affecting domestic and wild animals and have played a major role in the re-emergence of new outbreaks of bluetongue (BTV) and Schmallenberg (SBV) viruses in Europe. To determine vector-host specificity, trophic preference from blood meal analysis is of major importance in the surveillance of arthropod-borne diseases. Of 28,752 specimens collected, we identified 17 Culicoides species and investigated a total of 48 host sequences from the blood meals. Read More

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Invader removal triggers competitive release in a threatened avian predator.

Proc Natl Acad Sci U S A 2021 Aug;118(31)

Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331.

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. Read More

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Insect-mediated apparent competition between mammals in a boreal food web.

Proc Natl Acad Sci U S A 2021 Jul;118(30)

Centre d'étude de la forêt, Département de biologie, Université Laval, Québec, QC G1V 0A6, Canada;

While the important role of animal-mediated interactions in the top-down restructuring of plant communities is well documented, less is known of their ensuing repercussions at higher trophic levels. We demonstrate how typically decoupled ecological interactions may become intertwined such that the impact of an insect pest on forest structure and composition alters predator-prey interactions among large mammals. Specifically, we show how irruptions in a common, cyclic insect pest of the boreal forest, the spruce budworm (), modulated an indirect trophic interaction by initiating a flush in deciduous vegetation that benefited moose (), in turn strengthening apparent competition between moose and threatened boreal caribou () via wolf () predation. Read More

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The Potential Role of REG Family Proteins in Inflammatory and Inflammation-Associated Diseases of the Gastrointestinal Tract.

Int J Mol Sci 2021 Jul 3;22(13). Epub 2021 Jul 3.

Division of Gastroenterology and Hepatology, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya 663-8501, Japan.

Regenerating gene (REG) family proteins serve as multifunctional secretory molecules with trophic, antiapoptotic, anti-inflammatory, antimicrobial and probably immuno-regulatory effects. Since their discovery, accumulating evidence has clarified the potential roles of the REG family in the occurrence, progression and development of a wide range of inflammatory and inflammation-associated diseases of the gastrointestinal (GI) tract. However, significant gaps still exist due to the undefined nature of certain receptors, regulatory signaling pathways and possible interactions among distinct Reg members. Read More

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Homogenization of diatom assemblages is driven by eutrophication in tropical reservoirs.

Environ Pollut 2021 Jul 12;288:117778. Epub 2021 Jul 12.

Instituto de Botânica, Department of Ecology, Av. Miguel Estéfano 3687, 04301-902, São Paulo, SP, Brazil; Universidade Estadual Paulista "Júlio de Mesquita Filho" - UNESP, Av. 24A, 1515, 13506-900, Rio Claro, SP, campus, Rio Claro, SP, Brazil. Electronic address:

Eutrophication is one of the most widespread causes of biotic homogenization in freshwater ecosystems. Biotic homogenization can be characterized as reductions in local diversity (alpha) and occupation of available niches by more generalist species. Beta diversity is expected to decrease in more homogeneous communities, however, there is no consensus on how it responds to eutrophication. Read More

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Assessing pesticides exposure effects on the reproductive performance of a declining aerial insectivore.

Ecol Appl 2021 Jul 18:e02415. Epub 2021 Jul 18.

Département de biologie, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke, Qc, Canada, J1K 2R1.

In the context of increasing global environmental changes, it has become progressively important to understand the effects of human activity on wildlife populations. Declines in several avian populations have been observed since the 1970s, especially with respect to many farmland and grassland birds, which also include some aerial insectivores. Changes in farming practices referred to as agricultural intensification coincide with these major avian declines. Read More

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Autologous cell therapy in diabetes‑associated critical limb ischemia: From basic studies to clinical outcomes (Review).

Int J Mol Med 2021 Sep 19;48(3). Epub 2021 Jul 19.

Swiss Stem Cell Foundation, 6900 Lugano, Switzerland.

Cell therapy is becoming an attractive alternative for the treatment of patients with no‑option critical limb ischemia (CLI). The main benefits of cell therapy are the induction of therapeutic angiogenesis and neovascularization that lead to an increase in blood flow in the ischemic limb and tissue regeneration in non‑healing cutaneous trophic lesions. In the present review, the current state of the art of strategies in the cell therapy field are summarized, focusing on intra‑operative autologous cell concentrates in diabetic patients with CLI, examining different sources of cell concentrates and their mechanisms of action. Read More

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September 2021

Intermittent Hypoxia Training Prevents Deficient Learning-Memory Behavior in Mice Modeling Alzheimer's Disease: A Pilot Study.

Front Aging Neurosci 2021 1;13:674688. Epub 2021 Jul 1.

Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, United States.

In mouse models of Alzheimer's disease (AD), normobaric intermittent hypoxia training (IHT) can preserve neurobehavioral function when applied before deficits develop, but IHT's effectiveness after onset of amyloid-β (Aβ) accumulation is unclear. This study tested the hypothesis that IHT improves learning-memory behavior, diminishes Aβ accumulation in cerebral cortex and hippocampus, and enhances cerebrocortical contents of the neuroprotective trophic factors erythropoietin and brain-derived neurotrophic factor (BDNF) in mice manifesting AD traits. Twelve-month-old female 3xTg-AD mice were assigned to untreated 3xTg-AD ( = 6), AD+IHT ( = 6), and AD+sham-IHT ( = 6) groups; 8 untreated wild-type (WT) mice also were studied. Read More

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Parasites of Three Closely Related Antarctic Fish Species (Teleostei: Nototheniinae) from Elephant Island.

Acta Parasitol 2021 Jul 17. Epub 2021 Jul 17.

Institute for Ecology, Evolution and Diversity, Goethe University, 60438, Frankfurt am Main, Germany.

Background: Studies of parasite communities and patterns in the Antarctic are an important knowledge base with the potential to track shifts in ecological relations and study the effects of climate change on host-parasite systems. Endemic Nototheniinae is the dominant fish group found in Antarctic marine habitats. Through their intermediate position within the food web, Nototheniinae link lower to higher trophic levels and thereby also form an important component of parasite life cycles. Read More

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Sustained nitrogen loss in a symbiotic association of Comammox Nitrospira and Anammox bacteria.

Water Res 2021 Jul 11;202:117426. Epub 2021 Jul 11.

Civil and Environmental Engineering, University of Washington, Seattle, WA 98165, United States.

The discovery of anaerobic ammonia-oxidizing bacteria (Anammox) and, more recently, aerobic bacteria common in many natural and engineered systems that oxidize ammonia completely to nitrate (Comammox) have significantly altered our understanding of the global nitrogen cycle. A high affinity for ammonia (K ≈ 63nM) and oxygen place Comammox Nitrospira inopinata, the first described isolate, in the same trophic category as organisms such as some ammonia-oxidizing archaea. However, N. Read More

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Effects of short-duration oil exposure on bay anchovy (Anchoa mitchilli) embryos and larvae: mortality, malformation, and foraging.

Aquat Toxicol 2021 Jun 25;237:105904. Epub 2021 Jun 25.

Louisiana Universities Marine Consortium, 8124 Hwy. 56, Chauvin, Louisiana 70344, USA.

The Deepwater Horizon oil spill highlighted the need to understand the effects of oil exposure on marine eggs and larvae. To determine how short-duration exposure impacts the survivability of early life stages of the bay anchovy, Anchoa mitchilli, embryos and larvae ≤ 3-days-post-hatch (dph) were exposed to high-energy water accommodated fractions of weathered crude oil for 2 or 6 h. Lethal and sublethal effects of short-duration oil exposure were observed, including crippling malformations and altered optimal swimming and foraging behavior of larvae without malformation. Read More

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Environmental and life-history factors influence inter-colony multidimensional niche metrics of a breeding Arctic marine bird.

Sci Total Environ 2021 Jul 11;796:148935. Epub 2021 Jul 11.

University of Windsor, Windsor, Ontario N9B 3P4, Canada.

Human industrialization has resulted in rapid climate change, leading to wide-scale environmental shifts. These shifts can modify food web dynamics by altering the abundance and distribution of primary producers (ice algae and phytoplankton), as well as animals at higher trophic levels. Methylmercury (MeHg) is a neuro-endocrine disrupting compound which biomagnifies in animals as a function of prey choice, and as such bioavailability is affected by altered food web dynamics and adds an important risk-based dimension in studies of foraging ecology. Read More

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Plasticity of trophic interactions in fish assemblages results in temporal stability of benthic-pelagic couplings.

Mar Environ Res 2021 Jul 12;170:105412. Epub 2021 Jul 12.

Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, station marine de Wimereux, F-59000, Lille, France.

This study addresses the temporal variability of couplings between pelagic and benthic habitats for fish assemblages at five periods in a shallow epicontinental sea, the Eastern English Channel (EEC). Organic matter fluxes fueling fish assemblages and the relative contribution of their different sources were assessed using stable isotope analysis and associated isotopic functional metrics. Couplings between benthic and pelagic realms appeared to be a permanent feature in the EEC, potentially favored by shallow depth and driven by the combination of two trophic processes. Read More

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Effect of Drosophila suzukii on Blueberry VOC's: Chemical Cues for a Pupal Parasitoid, Trichopria anastrephae.

J Chem Ecol 2021 Jul 17. Epub 2021 Jul 17.

Laboratorio de Ecología Química, Facultad de Química, Universidad de La República, Montevideo, Uruguay.

Biocontrol agents such as parasitic wasps use long-range volatiles and host-associated cues from lower trophic levels to find their hosts. However, this chemical landscape may be altered by the invasion of exotic insect species. The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is a highly polyphagous fruit pest native to eastern Asia and recently arrived in South America. Read More

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Vector-borne plant pathogens modify top-down and bottom-up effects on insect herbivores.

Oecologia 2021 Jul 17. Epub 2021 Jul 17.

Department of Entomology, Washington State University, Pullman, WA, 99164, USA.

Ecological theory predicts that host-plant traits affect herbivore population growth rates, which in turn modulates predator-prey interactions. However, while vector-borne plant pathogens often alter traits of both host plants and vectors, a few studies have assessed how pathogens may act as interaction modifiers within tri-trophic food webs. By applying a food web motif framework, we assessed how a vector-borne plant pathogen (Pea-enation mosaic virus, PEMV) modified both bottom-up (plant-herbivore) and top-down (predator-prey) interactions. Read More

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Towards omics-based predictions of planktonic functional composition from environmental data.

Nat Commun 2021 07 16;12(1):4361. Epub 2021 Jul 16.

Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France.

Marine microbes play a crucial role in climate regulation, biogeochemical cycles, and trophic networks. Unprecedented amounts of data on planktonic communities were recently collected, sparking a need for innovative data-driven methodologies to quantify and predict their ecosystemic functions. We reanalyze 885 marine metagenome-assembled genomes through a network-based approach and detect 233,756 protein functional clusters, from which 15% are functionally unannotated. Read More

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Predator avoidance and foraging for food shape synchrony and response to perturbations in trophic metacommunities.

J Theor Biol 2021 Jul 13:110836. Epub 2021 Jul 13.

Theoretical 4 and Experimental Ecology Station, UPR 2001, CNRS, 09200 Moulis, France.

The response of species to perturbations strongly depends on spatial aspects in populations con nected by dispersal. Asynchronous fluctuations in biomass among populations lower the risk of simultaneous local extinctions and thus reduce the regional extinction risk. However, dispersal is often seen as passive diffusion that balances species abundance between distant patches, whereas ecological constraints, such as predator avoidance or foraging for food, trigger the movement of individuals. Read More

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Schindleria parva, a new species of Schindler's fish (Teleostei: Schindleriidae: Schindleria) from Jeddah, Saudi Arabia, Red Sea.

J Fish Biol 2021 Jul 16. Epub 2021 Jul 16.

Staatliches Museum für Naturkunde Stuttgart, Stuttgart, Germany.

Schindleria parva, a new species of the family Schindleriidae, is described from two specimens collected from the central Red Sea of Saudi Arabia. The new species is characterised by lack of pigmentation on the body, possession of an inconspicuous gas bladder and presence of small teeth on the premaxillae. The holotype is a female of 11 mm SL (11. Read More

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