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1.
Viruses ; 14(2)2022 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-35215924

RESUMO

The production of the aquaculture industry has increased to be equal to that of the world fisheries in recent years. However, aquaculture production faces threats such as infectious diseases. Betanodaviruses induce a neurological disease that affects fish species worldwide and is caused by nervous necrosis virus (NNV). NNV has a nude capsid protecting a bipartite RNA genome that consists of molecules RNA1 and RNA2. Four NNV strains distributed worldwide are discriminated according to sequence homology of the capsid protein encoded by RNA2. Since its first description over 30 years ago, the virus has expanded and reassortant strains have appeared. Preventive treatments prioritize the RGNNV (red-spotted grouper nervous necrosis virus) strain that has the highest optimum temperature for replication and the broadest range of susceptible species. There is strong concern about the spreading of NNV in the mariculture industry through contaminated diet. To surveil natural reservoirs of NNV in the western Mediterranean Sea, we collected invertebrate species in 2015 in the Alboran Sea. We report the detection of the RGNNV strain in two species of cephalopod mollusks (Alloteuthis media and Abralia veranyi), and in one decapod crustacean (Plesionika heterocarpus). According to RNA2 sequences obtained from invertebrate species and reported to date in the Mediterranean Sea, the strain RGNNV is predominant in this semienclosed sea. Neither an ecosystem- nor host-driven distribution of RGNNV were observed in the Mediterranean basin.


Assuntos
Decapodiformes/virologia , Reservatórios de Doenças/veterinária , Nodaviridae/isolamento & purificação , Pandalidae/virologia , Animais , Reservatórios de Doenças/virologia , Peixes/classificação , Peixes/virologia , Genoma Viral/genética , Mar Mediterrâneo , Nodaviridae/classificação , Nodaviridae/genética , Filogenia , RNA Viral/genética , Frutos do Mar/classificação , Frutos do Mar/virologia
2.
Mol Ecol ; 31(5): 1562-1576, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34936153

RESUMO

Information about the dietary composition of a species is crucial to understanding their position and role in the food web. Increasingly, molecular approaches such as DNA metabarcoding are used in studying trophic relationships, not least because they may alleviate problems such as low taxonomic resolution or underestimation of digestible taxa in the diet. Here, we used DNA metabarcoding with universal primers for cytochrome c oxidase I (COI) to study the diet composition of the northern shrimp (Pandalus borealis), an Arctic keystone species with large socio-economic importance. Across locations, jellyfish and chaetognaths were the most important components in the diet of P. borealis, jointly accounting for 40%-60% of the total read abundance. This dietary importance of gelatinous zooplankton contrasts sharply with published results based on stomach content analysis. At the same time, diet composition differed between fjord and shelf locations, pointing to different food webs supporting P. borealis in these two systems. Our study underlines the potential of molecular approaches to provide new insights into the diet of marine invertebrates that are difficult to obtain with traditional methods, and calls for a revision of the role of gelatinous zooplankton in the diet of the key Arctic species P. borealis, and in extension, Arctic food webs.


Assuntos
Código de Barras de DNA Taxonômico , Dieta , Pandalidae , Zooplâncton , Animais , Regiões Árticas , Cadeia Alimentar , Pandalidae/genética , Zooplâncton/genética
3.
Aquat Toxicol ; 240: 105966, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34555744

RESUMO

Swimming behaviour was investigated in adult egg-carrying northern shrimp (Pandalus borealis) exposed to dilute concentrations of the pesticides Alpha Max® (active ingredient deltamethrin) and Salmosan® (active ingredient azamethiphos) used to control parasitic copepods in salmon aquaculture. These treatments are applied topically within fish nets or well boats. Following a short treatment period, the pesticides are directly discharged to sea, exposing non-target organisms such as P. borealis to diluted concentrations of these chemicals. Locomotor activity was measured continuously in individual shrimp over several days within which they were exposed to treatments of diluted AlphaMax® or Salmosan®. Dilutions were based on modelling and dispersion studies from the literature and were considered environmentally realistic for greater than 1 km from point of discharge. 24 h continuous flow treatments were delivered within a 3.5-day monitoring period to observe the timeline of events following the release of treatment water, addressing questions of temporal responses in locomotor activity, recognising key time points of significant events and assessing the survival capacity of the shrimp. Exposure of shrimp to 1 ng l-1 deltamethrin triggered an immediate increase in swimming activity which reduced in intensity over the following 22 h leaving all shrimp either moribund or dead. A further exposure trial exposing shrimp to 0.2 ng l-1 deltamethrin (nominal) showed an increase in activity at the start of exposure that continued throughout the 24 h delivery, returning to previous levels by the end of the 3.5-day monitoring period. All these shrimps survived for at least four weeks after exposure, putting the threshold concentration of deltamethrin leading to immobility or death in adult P. borealis within this study at greater than 0.2 ng l-1 (nominal) and less than 1 ng l - 1 (measured). Exposure of P. borealis to azamethiphos at 30 ng l-1 induced several periods of significantly increased activity within the first 10 h of exposure and an extended period of reduced activity during post exposure, though no morbidity was observed with this treatment. No significant increase in activity or morbidity was observed in shrimp during a water vehicle control assessment. Shrimps exposed to a combination of 30 ng l-1 azamethiphos and 1 ng l-1 deltamethrin broadly followed the response pattern shown by shrimp exposed to 1 ng l-1 deltamethrin alone. Pesticide residues were not detected in post exposure tissue analyses for either chemical. The potential ecological significance of increased swimming activity at the start of pesticide exposures is discussed.


Assuntos
Copépodes , Pandalidae , Praguicidas , Poluentes Químicos da Água , Animais , Nitrilas , Organotiofosfatos , Praguicidas/toxicidade , Piretrinas , Salmão , Natação , Poluentes Químicos da Água/toxicidade
4.
Sci Rep ; 11(1): 18334, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526534

RESUMO

The development of non-antibiotic and environmentally friendly agents is a key consideration for health management in shrimp aquaculture. In this study, the probiotic potential in shrimp aquaculture of Pediococcus pentosaceus MR001, isolated from Macrobrachium rosenbergii, was investigated by means of feeding trial and genetic characterization. In the feeding trial, dietary supplementation with P. pentosaceus MR001 significantly increased weight gain and digestive enzyme activity (p < 0.05) in shrimp, Litopenaeus vannamei. The intestinal histology showed that shrimp given the probiotic diet had healthier guts than the control group. Also, the immune gene expression and the survival rate in the treatment group were significantly increased when compared with the control group. The genetic characteristics of P. pentosaceus strain MR001 were explored by performing whole-genome sequencing (WGS) using the HiSeq 2500 platform and PacBio system, revealing the complete circular genome of 1,804,896 bp. We also identified 1789 coding genes and subsequently characterized genes related to the biosynthesis of bacteriocins, stress resistance, and bile tolerance. Our findings suggest that insights in the functional and genetic characteristics of P. pentosaceus strain MR001 could provide opportunities for applications of such strain in shrimp diet supplementation.


Assuntos
Aquicultura/métodos , Genoma Bacteriano , Pandalidae/microbiologia , Pediococcus pentosaceus/genética , Probióticos , Animais , Pandalidae/crescimento & desenvolvimento , Pediococcus pentosaceus/patogenicidade
5.
PLoS One ; 16(7): e0253914, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34288940

RESUMO

The northern shrimp (Pandalus borealis Krøyer) population in the Gulf of Maine collapsed during an extreme heatwave that occurred across the Northwest Atlantic Ocean in 2012. Northern shrimp is a boreal species, and reaches its southern limit in the Gulf of Maine. Here we investigate proximate causes for the population collapse using data from fishery-independent surveys, environmental monitoring, and the commercial fishery. We first examined spatial data to confirm that the decline in population estimates was not due to a major displacement of the population, and then tested hypotheses related to fishing mortality and shifts in predation pressure. Fishing mortality may have contributed but could not explain the magnitude of the decline or the disappearance of pre-exploitable size individuals. Stomach contents analysis and biomass trends revealed no new fish predators of shrimp. However, longfin squid (Doryteuthis pealeii Lesueur) was unique among all species in showing time-series biomass peaks during spring, summer and fall of 2012, and spatial overlap with northern shrimp was unusually high in 2012. Longfin squid is a voracious and opportunistic predator that consumes crustaceans as well as fish. We hypothesize that the warmer temperatures of 2012 not only led to expansion of longfin squid distribution in Gulf of Maine, but had differential effects on migration phenology that further increased spatial overlap with northern shrimp. The weight of our evidence suggests that longfin squid predation was likely a significant factor in the collapse of northern shrimp in the Gulf of Maine.


Assuntos
Distribuição Animal , Mudança Climática , Decapodiformes/fisiologia , Pesqueiros/estatística & dados numéricos , Pandalidae , Comportamento Predatório , Animais , Oceano Atlântico , Temperatura Alta , Maine , Modelos Teóricos , Dinâmica Populacional , Estações do Ano
6.
Mar Environ Res ; 168: 105314, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33839401

RESUMO

In situ burning (ISB) is an oil spill clean-up option used by oil spill responders to mitigate impacts on the marine environment. Despite advantages such as high efficiency and potential applicability for challenging areas such as the Arctic, the actual environmental side effects are still uncertain. Acute and sublethal effects of the water accommodated fractions (WAFs from 25 g oil/L seawater) of a pre-weathered North Sea crude (Oseberg Blend 200 °C+) and field generated ISB residue were evaluated on Northern shrimp (Pandalus borealis) larvae. The larvae were first exposed for 96 h to a serial dilution of seven concentrations, and then maintained for two weeks in clean seawater post-exposure. No acute (mortality) or sublethal effects (feeding, development, or growth) were detected in any of the ISB residue concentrations. Significant larvae mortality was found in the three highest concentrations of crude oil (96-h LC50:469 µg/L total petroleum hydrocarbon) but no sublethal effects were found in the surviving larvae post-exposure. This study indicates that applying ISB could mitigate acute impacts of spilled oil on shrimp larvae.


Assuntos
Pandalidae , Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Animais , Larva , Mar do Norte , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade
7.
Zootaxa ; 4861(2): zootaxa.4861.2.10, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33311230

RESUMO

The commercial deep-sea caridean shrimp Plesionika martia (Milne-Edwards 1883) has long been recorded from India and constitutes an important species of deep-sea shrimp catches in the southern coast of India. However, the present study revealed that all the previous records of "Plesionika martia" is actually a misidentification of the closely related species P. semilaevis, which was recently obtained from Indian waters. The specimens were collected from three fish landing harbours (Sakthikulangara, Kalamuku, and Tuticorin) fished from the depth of about 150-250 m along the southern coast of India during 2014 to 2017. The level of interspecies genetic divergence between 16S rDNA (16.8-18.6%) and COI (26.1%) sequences of the Indian P. semilaevis and P. martia sequence retrieved from NCBI were found to be comparatively high. The current work illustrates the detailed morphological characters with color photographs of the species, P. semilaevis off the Indian Exclusive Economic Zone (EEZ).


Assuntos
Decápodes , Pandalidae , Animais , Índia
8.
Carbohydr Polym ; 246: 116648, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32747280

RESUMO

Conventional isolation of chitin from crustacean waste demands the use of high amounts of hazardous chemicals, hence not leading to a sustainable process. Atmospheric-pressure dielectric barrier discharge (DBD) plasma has demonstrated an enhanced ability to remove proteins directly from the biomass without the formation of any waste. Simultaneously, organic acids have proven very efficient in the removal of inorganic minerals from crustacean waste. Therefore, a hybrid process composed of DBD plasma and demineralization using organic acids has been successfully applied for the isolation of chitin. Results showed that the integration of nitrogen-based plasma and lactic acid demineralization allowed the elimination of 90 % of the proteins and ensures the complete removal of minerals from shrimp shells waste. The isolated chitin was further characterized using distinct techniques, namely XPS, ATR-FTIR, XRD and SEM. Chitin degree of deacetylation and molecular weight were also assessed. Hence, this work presents a sustainable and feasible platform for the extraction and purification of chitin from crustacean waste with almost zero waste formed.


Assuntos
Exoesqueleto/efeitos dos fármacos , Quitina/isolamento & purificação , Extração Líquido-Líquido/métodos , Gases em Plasma/química , Ácido Acético/química , Ácido Acético/farmacologia , Exoesqueleto/efeitos da radiação , Animais , Ácido Láctico/química , Ácido Láctico/farmacologia , Peso Molecular , Pandalidae , Resíduos/análise
9.
Mar Environ Res ; 159: 105007, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32662438

RESUMO

This study investigated effects of sea lice pharmaceuticals on egg-bearing deep-water shrimp (Pandalus borealis). Both mortality and sub-lethal effects (behavior, embryo development, and reproductive output) were studied for each of three pharmaceuticals alone and in different sequential combinations. The most severe effect was observed for deltamethrin where 2 h exposure to 330 times diluted treatment dose (alone and in sequential application with hydrogen peroxide and azamethiphos) induced almost 100% mortality within a few days after exposure. Similar effects were not observed for hydrogen peroxide or azamethiphos. However, sequential treatment of hydrogen peroxide and azamethiphos (2 h exposure to each pharmaceutical; 500 times dilution) resulted in >40% mortality during the first week following treatment. No sub-lethal effects or loss of eggs in female shrimp could be related to exposure to the bath treatments. Future studies should investigate potential sub-lethal effects at exposure concentrations close to the no-effect concentration.


Assuntos
Copépodes , Nitrilas , Pandalidae , Piretrinas , Animais , Peróxido de Hidrogênio , Nitrilas/toxicidade , Organotiofosfatos/toxicidade , Piretrinas/toxicidade
10.
Dis Aquat Organ ; 140(1): 109-118, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32701067

RESUMO

The Gulf of Maine northern shrimp Pandalus borealis population once supported a significant commercial winter fishery for the New England states. However, the fishery has been on moratorium since 2014 due to consecutive recruitment failures. The issue of parasite-infected eggs, so-called 'white eggs,' has long been identified for the Gulf of Maine northern shrimp, which makes shrimp eggs nonviable and subsequently hampers the recruitment potential. Furthermore, the proportion of infected females was observed to increase with water temperature. As Gulf of Maine temperatures have been increasing for decades, it is important to re-visit issues related to white eggs to evaluate possible impacts of climate-induced environmental changes on the white egg infection rates. We used biological samples collected by the Northeast Fisheries Science Center in 2012-2016 to evaluate the probability that a female shrimp was infected (Pinf) and the proportion of white eggs in an infected female shrimp (pwe). Although Pinf was high, with an average of 73.81% over the Gulf of Maine, pwe was mostly <5%. The variation in both Pinf and pwe examined in this study was not well explained by environmental factors or female body size. However, the average rates of both Pinf and pwe observed in this study were higher than those observed in the 1960s when the bottom temperatures were cooler. The results can be used to account for egg mortality and provide information on potential impacts of possible climate-induced variability on shrimp population dynamics.


Assuntos
Infecções/veterinária , Pandalidae , Animais , Feminino , Pesqueiros , Maine
11.
Mar Pollut Bull ; 156: 111202, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32510422

RESUMO

This study investigated the sensitivity of two deepsea species using mortality of northern shrimp (Pandalus borealis) and polyp activity of stony coral (Lophelia pertusa) to dispersant, Corexit 9500 and aromatic hydrocarbons (toluene, 2-methylnaphthalene, phenanthrene) in 96-h tests. Resulting hydrocarbon toxicity data were fit to the Target Lipid Model to generate predictive models and determine species sensitivity. Toxicity of chemically enhanced water accommodated fractions of Alaskan North Slope crude oil (ANS-oil) was also investigated with shrimp using nominal loading, total petroleum hydrocarbons and biomimetic extraction (BE) as oil exposure metrics. Coral were more sensitive to dispersant than shrimp while similar sensitivity was observed for hydrocarbons. Study and literature findings indicate deepsea species exhibit acute sensitivities to dispersant, hydrocarbons and oil that are comparable to pelagic species. Results support use of passive sampling methods to quantify dissolved oil for interpreting oil toxicity tests and suggest models for predicting time-dependence of toxicity warrant re-evaluation.


Assuntos
Antozoários , Pandalidae , Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Animais
12.
Zootaxa ; 4729(1): zootaxa.4729.1.4, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32229872

RESUMO

Material of the "Plesionika martia" (A. Milne-Edwards, 1883) species group from India had been reported as either P. martia or P. semilaevis Bate, 1888. Recent collection, however, revealed that both P .martia and P. semilaevis occur in Indian waters. COI barcoding gene sequence comparisons of the Indian and topotypic material of the four known species of the "P. martia" group showed that the Andaman Sea specimen is most similar to the topotypic specimens of P. martia even though there is high genetic divergence between them. For P. semilaevis, large sequence divergence is found in the topotypic material from the Philippines while the Indian specimens are genetically similar to one of the topotypic specimens. The characteristics of the Indian material of both species are described and illustrated.


Assuntos
Decápodes , Pandalidae , Animais
13.
Aquat Toxicol ; 222: 105453, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32112997

RESUMO

Anti-parasitic drugs used in the aquaculture industry are discharged to the sea after treatment of salmon. In this study, the effects of azamethiphos (AZA) in the Salmosan® formulation and deltamethrin (DEL) in the Alpha Max® formulation, have been assessed in Northern shrimp larvae (Pandalus borealis) when administered both separately and in combination. The exposure concentrations were 100 ng/L for AZA and 2 ng/L for DEL, each representing a 1000-fold dilution of the prescribed concentrations for salmon. These two chemicals were combined at these concentrations to give a third treatment (AZA + DEL). When larvae were exposed for two hours on the first, second and third days post hatch (dph), significantly increased mortality and reduced swimming activity were observed for larvae from the DEL and combined AZA + DEL treatments 4 dph, though not in larvae from the AZA treatment. A single pulse exposure, delivered on the first day post hatch, caused similar effects on mortality and swimming activity 4 dph as the three-pulse exposure. Mortality was driven by the presence of DEL in both experiments, with no amplification or reduction of effects observed when DEL and AZA were combined. Larvae were observed for 13 days following the single pulse exposure, with food limitation introduced as an additional stressor on day 4. In the DEL and AZA + DEL treatments mortality continued to increase regardless of food level, with no larvae completing development to stage II. The overriding toxicity of DEL masked any potential effects the reduced food ration may have exerted. Swimming activity was lower for AZA treated larvae than Control larvae 13 dph, when both groups were fed daily, though no other significant changes to mortality, development to stage II, feeding rate or gene expression were observed. Food limited Control and AZA larvae had lower swimming activity and feeding rate than daily fed Control larvae, with expression of pyruvate kinase and myosin genes also downregulated. However, there was no negative effect on survival or successful development to stage II in these treatments. In addition, mesencephalic astrocyte-derived neurotropic factor was downregulated in food limited Control larvae when compared with the daily fed Controls. Results from this study together with reported estimates of dispersion plume concentrations of discharged pesticides indicate that toxic concentrations of deltamethrin could reach shrimp larvae several kilometers from a treated salmon farm.


Assuntos
Ração Animal , Aquicultura/métodos , Larva/efeitos dos fármacos , Pandalidae/efeitos dos fármacos , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Nitrilas/toxicidade , Organotiofosfatos/toxicidade , Piretrinas/toxicidade , Salmão/crescimento & desenvolvimento
14.
Mar Pollut Bull ; 151: 110892, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056658

RESUMO

The application of chemical dispersants is one option of oil spill response (OSR). Here, Northern shrimp (Pandalus borealis) larvae were experimentally exposed for short periods (6 h and 1 h) to a realistic concentration of chemically dispersed oil (CDO) (~10 mg L-1 THC), mechanically dispersed oil (MDO) (~7 mg L-1 THC), and dispersant only (D). A control (C) with seawater served as reference. Short-term effects on survival and feeding were examined right after exposure and longer-term consequences on survival, feeding, growth and development following 30 days of recovery. Both exposure durations provoked long lasting effects on larval fitness, with 1 h exposure leading to minor effects on most of the selected endpoints. The 6 h exposure affected all endpoints with more adverse impacts after exposure to CDO. This study provides important data for assessing the best OSR option relevant to NEBA (Net Environmental Benefit Analysis).


Assuntos
Pandalidae , Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Animais , Larva
15.
Sci Rep ; 10(1): 1287, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992795

RESUMO

The Northern spot shrimp, Pandalus platyceros, a protandric hermaphrodite of commercial importance in North America, is the primary target species for shrimp fisheries within Southeast Alaska. Fishery data obtained from the Alaska Department of Fish and Game indicate that spot shrimp populations have been declining significantly over the past 25 years. We collected spot shrimps in Southeast Alaska and measured reproductive-related morphological, gonadal and molecular changes during the entire life history. The appendix masculina, a major sexual morphological indicator, is indicative of the reproductive phase of the animal, lengthening during maturation from juvenile to the male phase and then gradually shortening throughout the transitional stages until its complete disappearance upon transformation to a female. This morphological change occurs in parallel with the degeneration of testicular tissue in the ovotestis and enhanced ovarian vitellogenesis. Moreover, we obtained the entire mRNA sequence of the yolk protein precursor, vitellogenin, and monitored its transcript levels throughout the entire shrimp life-cycle. Vitellogenin transcript levels in the hepatopancreas increased in the early transitional stage until reaching a peak prior to extruding eggs. Such transcriptomic analyses, coupled with a comprehensive description of the gonad, external sex characters and timing of the reproductive life history of spot shrimps contribute to a better understanding of the hermaphroditic reproduction process in the cold Southeast Alaskan waters. This knowledge can contribute to a revision of current conservation efforts to maintain wild populations sustainable for both commercial and ecological considerations.


Assuntos
Proteínas de Artrópodes , Pesqueiros , Pandalidae , RNA Mensageiro , Análise de Sequência de RNA , Transcriptoma , Alaska , Animais , Proteínas de Artrópodes/biossíntese , Proteínas de Artrópodes/genética , Conservação de Recursos Energéticos , Pandalidae/genética , Pandalidae/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética
16.
Food Chem ; 302: 125299, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31437710

RESUMO

Flocculation and sedimentation of a protein-rich biomass from shrimp boiling water (SBW) using food grade polysaccharides (carrageenan, alginate and carboxymethyl cellulose (CMC)) as flocculants was investigated at different pH-values. The effect of flocculant concentration on particle size and viscosity of SBW was also evaluated. Flocculation with carrageenan (0.45 g/L) at pH = 4 exhibited the most efficient protein sedimentation; protein concentration of the upper phase was here reduced by 77%, allowing 86% protein to be sedimented from SBW. Flocculation by alginate and CMC at pH = 4 showed 67% and 60% protein reduction of the upper phase at concentrations of 0.5 and 0.2 g/L, respectively. Contrary to alginate and CMC, carrageenan concentration affected the size distribution of flocs. Finally, carrageenan at 0.45 g/L and pH = 4 was successfully tested in a scaled up trial (5L) providing 78.5% protein recovery and a biomass with 75% protein on dry weight basis.


Assuntos
Proteínas de Peixes/isolamento & purificação , Manipulação de Alimentos/métodos , Pandalidae/química , Alginatos/química , Animais , Carboximetilcelulose Sódica/química , Carragenina/química , Floculação , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Viscosidade , Águas Residuárias/química
17.
Zootaxa ; 4590(4): zootaxa.4590.4.3, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31716081

RESUMO

Deep-sea shrimps of the species Plesionika acanthonotus (Smith, 1882) and P. holthuisi Crosnier Forest, 1968 are morphologically similar and exhibit overlapping amphi-Atlantic distributions. In the literature, through morphological studies, there are reports of doubts about the validity of P. holthuisi and some authors believe that the eastern and western Atlantic populations of P. acanthonothus could represent two distinct species. The objective of the present study was to use molecular data to elucidate the taxonomic status of the two populations of P. acanthonothus. DNA sequences of two mitochondrial genes (16S rDNA and Cytochrome Oxidase subunit I) and a nuclear gene (Histone 3) were obtained for both species and for both populations of P. acanthonotus. The sequences were also obtained from Genbank for comparison. The trees (separate and multi-locus/partitioned genes) were generated by Bayesian Inference analyzes, and genetic divergence (Kimura-2-parameters) was also calculated. All specimens that had their DNA sequenced were examined morphologically to confirm their identification; morphological variations were noted. The genetic data showed that Plesionika holthuisi is closely related to P. acanthonotus, but clearly separated, indicating that P. holthuisi is a valid species. In the multi-locus analysis, the P. acanthonothus specimens were divided into two clades, one with the eastern Atlantic specimens and another with the western Atlantic specimens. However, this genetic separation was considered to be a population structuring for three reasons: (1) the genetic divergences of the two mitochondrial genes between these two groups (eastern Atlantic X western Atlantic) were smaller than the interspecific divergence for Plesionika; (2) the P. acanthonothus sequences of the Histone 3 gene showed no genetic variation; (3) in the analyzed individuals, no valid morphological character was found to support this separation. Thus, the conclusion of this study is that P. holthuisi probably is a valid species and P. acanthonothus presents two populations with mitochondrial divergences that could be in the process of speciation, but which currently represent only one species.


Assuntos
Decápodes , Pandalidae , Animais , Teorema de Bayes , DNA Mitocondrial , DNA Ribossômico , Filogenia
18.
Zootaxa ; 4565(1): zootaxa.4565.1.3, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-31716489

RESUMO

A rare species of pandalid shrimp, Heterocarpus nesisi Burukovsky, 1986, is rediscovered in deep water off western Mexico. Previous to this capture, this species was known only from the holotype, a mature male captured at 800 m depth, originally described in the genus Heterocarpus and later transferred to Plesionika. A second, unconfirmed record, was provided in 1989: a female captured at 898 m near the southern tip of the Baja California Peninsula. Heterocarpus nesisi is redescribed and appendages are illustrated. The general morphology of this species makes it difficult to fit within Heterocarpus or Plesionika, and a new genus, Heteronika gen. nov., is proposed to accommodate it. Heteronika nesisi is associated with the lower boundary of the Oxygen Minimum Zone occurring off western Baja California.


Assuntos
Decápodes , Pandalidae , Animais , Feminino , Masculino , México
19.
Mar Pollut Bull ; 145: 409-417, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590804

RESUMO

Knowledge of key species sensitivity for oil spill response (OSR) options is needed to support decision-making and mitigate impact on sensitive life stages of keystone species. Here, Northern shrimp (Pandalus borealis) larvae were exposed for 24 h to a gradient (H-High, M-Medium: 10 times dilution and L-Low: 100 times dilution) of mechanically- (MDO) (H < 6 mg/L total hydrocarbon content) and chemically- (CDO) dispersed oil (Slickgone NS, H < 20 mg/L total hydrocarbon content), followed by a recovery period. Larval mortality, feeding rate and development were evaluated. Overall, the results show that 24 h exposure to field-realistic concentrations of CDO lead to lower survival, reduced feeding rate and slower larval development in P. borealis larvae compared to MDO. These effects persisted during recovery, indicating a higher vulnerability with dispersant use and the need for longer observation periods post-exposure to fully evaluate the consequences for sensitive life-stages from OSR.


Assuntos
Pandalidae/efeitos dos fármacos , Poluição por Petróleo , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Pandalidae/crescimento & desenvolvimento , Poluentes Químicos da Água/química
20.
PLoS One ; 14(9): e0222391, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31513691

RESUMO

Shrimp trawlers in the Barents Sea use a Nordmøre sorting grid ahead of a small-mesh codend to avoid bycatch while catching shrimps efficiently. However, small fish can still pass through the grid to enter the codend, which increases their risk of being retained. In this study, we quantified the selectivity of a standard Nordmøre grid used together with one of two different codend designs, namely a diamond mesh codend with square mesh panels and a codend with a square mesh sorting cone section, for deep-water shrimp (Pandalus borealis), redfish (Sebastes spp.), and American plaice (Hippoglossoides platessoides). For the first time, the selective properties of these two alternative designs were estimated and compared to those of a Nordmøre grid used together with a 35-mm diamond mesh codend, which is the compulsory gear used in the fishery today. With this traditional codend, the size selectivity of both bycatch species showed the expected characteristic bell-shaped size selection pattern, with low retention probability of very small fish and bigger fish but with high retention probability of certain sizes of juveniles. Using the square mesh sorting cone significantly reduced the maximum retention risk of redfish. The maximum retention with the diamond mesh codend with square mesh panels was estimated to be 14% lower than that of the traditional codend, but the difference was not statistically significant. The two alternative codend designs did not result in any significant reduction in bycatch of American plaice.


Assuntos
Aquicultura/métodos , Penaeidae , Animais , Crustáceos , Pesqueiros/economia , Peixes , Noruega , Pandalidae , Alimentos Marinhos
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