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1.
PLoS One ; 15(1): e0223396, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31995553

RESUMO

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for explaining the position of non-swimming larvae in the water column. Due to embryonic morphology and ecology diversities, egg buoyancy has important variations within one species and among other ones. Nevertheless, it has hardly been explored if this buoyancy variability can be a strategy for deep-sea larvae to optimize their transport beyond their spawning areas. In the northwestern Mediterranean Sea, protozoea and mysis larvae of the commercial deep-sea shrimp Aristeus antennatus were recently found in upper layers, but to present, earlier stages like eggs and nauplii have not been collected. Using a Lagrangian transport model and larval characteristics, we evaluate the buoyancy and hydrodynamic effects on the transport of A. antennatus' larvae in the northwestern Mediterranean Sea. The transport models suggested that 75% of buoyant eggs released between 500 and 800 m depth (i.e., known spawning area), reached the upper water layers (0-75 m depth). Then, according to the modeled larval drifts, three spawning regions were defined in the studied area: 1) the northern part, along a continental margin crossed by large submarine canyons; 2) the central part, with two circular circulation structures (i.e., eddies); and 3) the southern part, with currents flowing through a channel. The number of larvae in the most upper layer (0-5 m depth) was higher if the larval transport model accounted for the ascent of eggs and nauplii (81%) instead of eggs reaching the surface before hatching (50%). The larvae reaching the most water upper layer (0-5 m depth) had higher rates of dispersal than the ones transported below the surface layer (deeper than 5 m depth). The results of larval dispersal simulations have implications for the understanding of A. antennatus larval ecology and for management decisions related to the shrimp fisheries in the northwestern Mediterranean Sea.


Assuntos
Crustáceos/fisiologia , Larva/fisiologia , Modelos Biológicos , Óvulo/fisiologia , Animais , Pesqueiros , Peixes/fisiologia , Hidrodinâmica , Mar Mediterrâneo , Alimentos Marinhos
2.
Sci Total Environ ; 702: 134993, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31726336

RESUMO

Since the establishment of the whole-contact sediment toxicity test using Heterocypris incongruens in 2012, this user-friendly method has been widely used for the assessment of many kinds of solid samples, such as sediment, soil, compost, and sewage sludge. There are two endpoints for this method: mortality and growth inhibition. Currently, there is no standard toxicity threshold established for the endpoint of growth inhibition. However, there is evidence showing that the calcite saturation state of the overlying water, which might be different among various samples, influences the growth and survival of H. incongruens. Thus, it is necessary to characterize the influence of the calcite saturation state to ensure that the test results are reliable and comparable among different samples. In the present study, we created artificial sediments comprised of quartz sand and 0-20% calcite particulates to manipulate the calcite saturation state in the overlying water and performed the test using H. incongruens for 6 d. The results show that a low calcite saturation state inhibited the growth of H. incongruens but had no effect on survival rate. The growth of ostracods was linearly related to the calcite saturation index of the overlying water. Additionally, a formula for artificial sediment consisting of 10% calcite and 90% quartz sand for the H. incongruens toxicity test was proposed. This study helps to distinguish H. incongruens growth inhibition caused by calcite saturation from that caused by toxicity.


Assuntos
Carbonato de Cálcio/química , Crustáceos/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Fenômenos Biológicos , Sedimentos Geológicos/química , Esgotos , Solo , Testes de Toxicidade , Poluentes Químicos da Água/normas
3.
Zoolog Sci ; 36(6): 468-470, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31833317

RESUMO

This study describes shell-exchange behavior in the hermit-crab-like tanaidacean Macrolabrum sp. (Pagurapseudidae: Pagurapseudinae) under captive conditions. I observed one shell exchange by Macrolabrum sp., the behavioral sequence of which was as follows: a shell-carrying tanaidacean 1) grasped the edge of the aperture of an empty gastropod shell with its right cheliped; 2) inspected the condition inside the shell four times by inserting the anterior portion of its body into the shell; and 3) moved into the shell, posterior end (pleotelson) first. The elapsed time from the initial grasping of the empty shell to completing the move into it was 2 min 20 sec. In contrast to a Pagurapseudes tanaidacean and hermit crabs, the individual of Macrolabrum sp. did not examine the external surface of the shell during the single shell exchange observed.


Assuntos
Exoesqueleto , Comportamento Animal , Crustáceos/fisiologia , Animais
4.
Zoolog Sci ; 36(6): 511-520, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31833322

RESUMO

To gain a better understanding of the effect of reproductive modes and swimming ability on ostracod distribution, we visited 111 randomly selected aquatic sites in Kirsehir province. A total of 35 ostracods were newly reported for the area. The number of species with and without swimming setae was not statistically different, but numbers of sexual species was significantly lower than parthenogenetics. Species without setae did not show a significant difference between sexual and parthenogenetic forms. Numbers of species with (out) setae were not significant among different elevational ranges. Distribution of parthenogenetic species was common in all 11 habitat types when sexual species were only found from three different types located from 690 to ca. 1400 m of elevational ranges. Numbers of parthenogenetic species with or without setae did not show a difference among the ranges, but sexual species without setae exhibited wider distributional ranges (690-1289 m) than species with swimming setae (690-1089 m). Species' co-occurrence revealed two positive, five negative, and 44 random pairs of co-occurrences. Wards cluster analyses portrayed three main clustering groups. While group I includes parthenogenetic and sexual species, group II covers mostly parthenogenetic species with and without setae. Group III consists of species without setae. CCA results displayed three environmental variables (water temperature, pH and elevation) effective on species distribution. Species distributed in all elevational ranges tend to show lower optimum and wider ecological tolerances. Parthenogenetic species with swimming setae and with relatively higher tolerance ranges were dominant over sexual species. The present results suggest that swimming mode has a greater effect on species distribution among the habitats than reproductive modes.


Assuntos
Crustáceos/fisiologia , Ecossistema , Natação/fisiologia , Distribuição Animal , Animais , Reprodução/fisiologia , Especificidade da Espécie , Turquia
5.
Cell Tissue Res ; 377(3): 415-443, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31270611

RESUMO

The digestive system of the malacostracan crustaceans, namely the decapods, isopods, amphipods and mysids, is among the most complex organ systems of the animal kingdom serving multiple functions such as food processing, absorption and storage of nutrients, synthesis of digestive enzymes and blood proteins, detoxification of xenobiotics and osmoregulation. It is rather well investigated compared to other invertebrates because the Malacostraca include many ecological keystone species and food items for humans. The Decapoda and Peracarida share food processing with chewing and filtering structures of the stomach but differ with respect to morphology and ultrastructure of the digestive glands. In the Peracarida, the digestive glands are composed of few, relatively large lateral caeca, whereas in the Decapoda, hundreds to thousands of blindly ending tubules form a voluminous hepatopancreas. Morphogenesis and onset of functionality of the digestive system strongly depend on the mode of development. The digestive system is early developed in species with feeding planktonic larvae and appears late in species with direct lecithotrophic development. Some structures of the digestive system like the stomach ossicles are rather constant in higher taxa and are of taxonomic value, whereas others like the chewing structures are to some degree adapted to the feeding strategy. The nutrient absorbing and storing cells of the digestive glands show considerable ultrastructural variation during moult cycle, vitellogenesis and starvation. Some of the various functions of the digestive system are already assigned to specific sections of the digestive tract and cell types, but others still await precise localization.


Assuntos
Crustáceos/anatomia & histologia , Crustáceos/fisiologia , Trato Gastrointestinal/anatomia & histologia , Trato Gastrointestinal/crescimento & desenvolvimento , Animais , Morfogênese
6.
Aquat Toxicol ; 214: 105255, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31325645

RESUMO

The heavy metal cadmium readily accumulates in organisms, causing damage. In this study, juvenile marine shrimp Marsupenaeus japonicus were exposed to cadmium (Cd2+; 5, 50 and 500 µg L-1). Cd accumulation and antioxidant-related indices were determined, and damage to biomolecules was assessed, after 24, 48 and 96 h. Cd bioaccumulation in M. japonicus increased with exposure time and concentration, which reached the highest value at 96 h. The data showed that 5, 50 and 500 µg L-1 Cd increased glutathione (GSH) content and the activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) in a Cd-dose-dependent manner, but 5 and 50 µg L-1 Cd had no effect on caspase-3 activity. The expression levels of SOD, GST, heat shock protein 70 (HSP70), metallothionein (MT), p53 and caspase-3 genes were rapidly increased after 50 and 500 µg L-1 Cd exposure, and remained at a significantly higher level than in the control after 96 h of exposure. After exposure to 5, 50 and 500 µg L-1 Cd, F-value (the ratio between double-stranded DNA and total DNA) remained high at 24 h, however, as the exposure time increased, the F-value decreased in a dose-dependent manner. An increase in malondialdehyde content was also observed following exposure to 50 and 500 µg L-1 Cd. Our data suggest that Cd induces oxidative stress, molecular damage and apoptosis in juvenile M. japonicus in a concentration- and time-dependent manner.


Assuntos
Cádmio/toxicidade , Crustáceos/fisiologia , Exposição Ambiental , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Crustáceos/efeitos dos fármacos , Crustáceos/enzimologia , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Poluentes Químicos da Água/toxicidade
7.
PLoS One ; 14(6): e0218238, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31242214

RESUMO

Ocean acidification (O.A.) influences the ecology of oceans and it may impact plant-animal interactions at various levels. Seagrass meadows located at acidified vents in the Bay of Naples (Italy) are considered an open window to forecast the effects of global-changes on aquatic communities. Epiphytic diatoms of the genus Cocconeis are abundant in seagrass meadows, including acidified environments, where they play key ecological roles. A still-unknown apoptogenic compound produced by Cocconeis triggers the suicide of the androgenic gland of Hippolyte inermis Leach 1816, a protandric hermaphroditic shrimp distributed in P. oceanica meadows located both at normal pH and in acidified vents. Feeding on Cocconeis sp. was proven important for the stability of the shrimp's natural populations. Since O.A. affects the physiology of diatoms, we investigated if, in future scenarios of O.A., Cocconeis scutellum parva will still produce an effect on shrimp's physiology. Cell densities of Cocconeis scutellum parva cultivated in custom-designed photobioreactors at two pH conditions (pH 7.7 and 8.2) were compared. In addition, we determined the effects of the ingestion of diatoms on the process of sex reversal of H. inermis and we calculated the % female on the total of mature individuals-1 (F/mat). We observed significant differences in cell densities of C. scutellum parva at the two pH conditions. In fact, the highest cell densities (148,808 ±13,935 cells. mm-2) was obtained at day 13 (pH 7.7) and it is higher than the highest cell densities (38,066 (±4,166) cells. mm-2, day 13) produced at pH 8.2. Diatoms cultured at acidified conditions changed their metabolism. In fact, diatoms grown in acidified conditions produced in H. inermis a proportion of females (F/mat 36.3 ±5.9%) significantly lower than diatoms produced at normal pH (68.5 ±2.8), and it was not significantly different from that elicited by negative controls (31.7 ±5.6%).


Assuntos
Ácidos/química , Crustáceos/fisiologia , Oceanos e Mares , Estramenópilas/fisiologia , Animais , Feminino , Masculino , Fotobiorreatores , Água do Mar
8.
Proc Biol Sci ; 286(1894): 20182621, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30963873

RESUMO

Mating behaviours are diverse and noteworthy, especially within species radiations where they may contribute to speciation. Studying how differences in mating behaviours arise between species can help us understand how diversity is generated at multiple biological levels. The bioluminescent courtship displays of cypridinid ostracods (or sea fireflies) are an excellent system for this because amazing variety evolves while using a conserved biochemical mechanism. We find that the evolution of one aspect in this behavioural phenotype-the duration of bioluminescent courtship pulses-is shaped by biochemical function. First, by measuring light production from induced bioluminescence in 38 species, we discovered differences between species in their biochemical reactions. Then, for 16 species for which biochemical, phylogenetic and behavioural data are all available, we used phylogenetic comparative models to show that differences in biochemical reaction are nonlinearly correlated with the duration of courtship pulses. This relationship indicates that changes to both enzyme (c-luciferase) function and usage have shaped the evolution of courtship displays, but that they differentially contribute to these phenotypic changes. This nonlinear dynamic may have consequences for the disparity of signalling phenotypes observed across species, and demonstrates how unappreciated diversity at the biochemical level can lead to inferences about behavioural evolution.


Assuntos
Evolução Biológica , Corte , Crustáceos/fisiologia , Sinais (Psicologia) , Fenótipo , Animais , Crustáceos/enzimologia , Feminino , Luminescência , Masculino
9.
Fish Shellfish Immunol ; 87: 820-828, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30779995

RESUMO

Probiotics use in aquaculture has gained attention as microbial candidates to maintain the health and the well-being of many aquaculture animals. Among the many microbial candidates, probiotic Bacillus has sporulation capacity that makes them survive harsh environmental conditions, are non-pathogenic and non-toxic when fed to fish, and can produce antimicrobial substances making them more suitable candidates compared to other probiotics. In this review, we discussed the necessity of using the probiotic Bacillus in sustainable aquaculture as a good alternative to improve feed utilization, stress response, immune response and disease resistance, maintenance of tissue integrity, and as well improvement of water quality for sustainable aquaculture. Therefore the findings of current researches about the effects of Bacillus application to improve the culture of aquatic animals for future research and development of Bacillus application in aquaculture have been summarised.


Assuntos
Ração Animal/análise , Aquicultura/métodos , Bacillus/química , Crustáceos/fisiologia , Peixes/fisiologia , Moluscos/fisiologia , Probióticos/farmacologia , Animais , Crustáceos/crescimento & desenvolvimento , Crustáceos/imunologia , Dieta/veterinária , Resistência à Doença/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Moluscos/crescimento & desenvolvimento , Moluscos/imunologia , Estresse Fisiológico/efeitos dos fármacos , Qualidade da Água
10.
Integr Zool ; 14(6): 561-575, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30811879

RESUMO

Fossil cephalopods are frequently encrusted by epibionts; however, determining whether encrustation occurred prior to or post-mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post-mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta, with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post-mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.


Assuntos
Exoesqueleto , Crustáceos/classificação , Nautilus , Animais , Crustáceos/fisiologia , Nova Caledônia , Oceano Pacífico
11.
Artigo em Inglês | MEDLINE | ID: mdl-30634154

RESUMO

To explore the molecular mechanisms underlying the initial differentiation and formation of papillae in sea cucumbers, the transcriptomes of Apostichopus japonicus pentactulae (without papillae) were compared to those of A. japonicus juveniles (with papillae). From the RNA of the three pentactula libraries and the three juvenile libraries, we obtained 41-46 million raw reads, yielding 39-45 million clean reads. From these, we generated 599,673 transcripts and identified 230,604 unigenes. Across all six transcriptomes, we identified 246,207 single nucleotide polymorphisms (SNPs) and 80,455 single sequence repeats (SSRs). There were more transition SNPs (60.74%) than transversion SNPs (39.26%). The mononucleotide repeat was the most abundant SSR motif. We identified 7965 differentially expressed unigenes (DEGs) in the juveniles and the pentactulae; 2421 DEGs were expressed only in the juveniles, and 1238 were expressed only in the pentactulae. Of all DEGs, 5215 were significantly upregulated and 2750 were significantly downregulated in the juveniles as compared to the pentactulae. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that the DEGs were primarily enriched in ribosome synthesis, cell proliferation, tight junction formation, collagen fibrillogenesis, and neurogenesis.


Assuntos
Ritmo Circadiano/genética , Crustáceos/fisiologia , Perfilação da Expressão Gênica , Maturidade Sexual/genética , Animais , Proteínas de Artrópodes/genética , Crustáceos/genética , DNA Complementar/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Reação em Cadeia da Polimerase em Tempo Real
12.
Integr Environ Assess Manag ; 15(1): 29-39, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30117277

RESUMO

Risk assessments for plant protection products and their active ingredients that are based on standard laboratory tests performed under constant exposure conditions may result in an overestimation of risks because exposure in the environment is often characterized by a few short peaks. Here, the General Unified Threshold Model of Survival (GUTS) was used to conduct a refined risk assessment for the herbicide tembotrione and its effects on the marine invertebrate Americamysis bahia, for which the standard chronic effect assessment failed. The GUTS model was first calibrated with time-to-effect and concentration-response data from 2 independent acute experiments with A. bahia. Model parameters for both toxicodynamic assumptions of stochastic death (SD) and individual tolerance (IT) were estimated with the reduced GUTS model (GUTS-RED) using the scaled internal concentration as a dose metric. Both the calibrated GUTS-RED-SD and GUTS-RED-IT models described survival dynamics well. Model validation using datasets of 2 independent chronic tests yielded robust predictions of long-term toxicity of tembotrione on A. bahia, with GUTS-RED-IT being more reliable than GUTS-RED-SD. The validated model was subsequently used to predict survival from time-variable exposure profiles, as derived from the FOrum for Co-ordination of pesticide fate models and their USe (FOCUS). Because ecotoxicological independence of peaks had not been empirically verified, the link between exposure and effects was assessed with complete exposure profiles. Effect thresholds resulting from different peak exposure concentrations and durations were determined with GUTS and directly compared with the exposure concentrations from the FOCUS surface water scenarios. The derived values were higher than the predicted FOCUS critical concentrations. Additionally, comparing the areas under the curve (AUCs) derived with GUTS for multiple peak exposure profiles to those from FOCUS revealed significant additional safety margins, demonstrating that only unrealistically high exposure concentrations would produce significant effects. In conclusion, no unacceptable effects of tembotrione on aquatic invertebrates under realistic environmental exposure conditions are expected. Integr Environ Assess Manag 2019;15:29-39. © 2018 SETAC.


Assuntos
Crustáceos/fisiologia , Monitoramento Ambiental/métodos , Herbicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brasil , Medição de Risco , Testes de Toxicidade
13.
J Steroid Biochem Mol Biol ; 185: 172-183, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30157455

RESUMO

Arthropods have long been utilized as models to explore molecular function, and the findings derived from them can be applied throughout metazoa, including as a basis for medical research. This has led to the adoption of many representative insect models beyond Drosophila, as each lends its own unique perspective to questions in endocrinology and genetics. However, non-insect arthropods are yet to be realised for the potential insight they may provide in such studies. The Crustacea are among the most ancient arthropods from which insects descended, comprising a huge variety of life histories and ecological roles. Of the events in a typical crustacean development, metamorphosis is perhaps the most ubiquitous, challenging and highly studied. Despite this, our knowledge of the endocrinology which underpins metamorphosis is rudimentary at best; although several key molecules have been identified and studied in depth, the link between them is quite nebulous and leans heavily on well-explored insect models, which diverged from the Pancrustacea over 450 million years ago. As omics technologies become increasingly accessible, they bring the prospect of explorative molecular research which will allow us to uncover components and pathways unique to crustaceans. This review reconciles known components of crustacean metamorphosis and reflects on our findings in insects to outline a future search space, with focus given to the ecdysone cascade. To expand our knowledge of this ubiquitous endocrine system not only aids in our understanding of crustacean metamorphosis, but also provides a deeper insight into the adaptive capacity of arthropods throughout evolution.


Assuntos
Crustáceos/fisiologia , Ecdisona/metabolismo , Sistema Endócrino/fisiologia , Insetos/fisiologia , Muda/fisiologia , Animais , Modelos Animais
14.
Artigo em Inglês | MEDLINE | ID: mdl-30580103

RESUMO

Molting in crustaceans is a highly complex physiological process involving regulation by two paired endocrine glands, the X-organ/sinus gland complex (XO/SG) and the Y-organ (YO). The XO/SG complex is responsible for making molt-inhibiting hormone, which negatively regulates synthesis of molting hormones, ecdysteroids, by the YO. In this study, changes in protein abundance in the YO were characterized over the course of a molt cycle induced by multiple leg autotomy in the blackback land crab, Gecarcinus lateralis. In all, 457 distinct protein spots were detected using two-dimensional gel electrophoresis, of which 230 (50%) changed significantly in abundance over the course of the molt cycle. Protein abundance differed most notably between intermolt and the three premolt stages, indicative of a biological 'on-off' switch. Changes in hemolymph proteins were correlated with stage-specific processes of sclerotization and melanization that facilitate cuticle hardening and support immune reactions. An abundance of cytoskeletal proteins were identified, which corresponded with glandular hypertrophy associated with synthesis and secretion of ecdysteroids. Many proteins involved in energetic pathways including glycolysis, the citric acid cycle, amino acid metabolism, and one­carbon metabolism changed in abundance in response to increasing energy demands and the requirement for precursors of macromolecular synthesis. Several proteins involved in immune, proteostasis, and oxidative stress responses were correlated with the dynamic and demanding cellular changes associated with ecdysteroidogenesis. These changes in diverse physiological pathways represent the complexity involved with molecular regulation of the YO in decapod crustaceans.


Assuntos
Proteínas de Artrópodes/metabolismo , Crustáceos/metabolismo , Ecdisona/metabolismo , Proteômica , Animais , Proteínas Sanguíneas/metabolismo , Crustáceos/imunologia , Crustáceos/fisiologia , Proteínas do Citoesqueleto/metabolismo , Eletroforese em Gel Bidimensional , Metabolismo Energético , Ensaio de Imunoadsorção Enzimática , Hemolinfa/metabolismo , Masculino , Proteostase , Espectrometria de Massas em Tandem
15.
An Acad Bras Cienc ; 91(1): e20180232, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30569968

RESUMO

Most studies evaluating the impacts of river pollution in the semi-arid region of Brazil have been geared towards physiochemical analyses, and investigations of the adverse effects of water pollution on associated organisms are scarce. This study aimed to evaluate the water quality in the Poxim river estuary in Aracaju, Sergipe throughout the dry and rainy season by evaluating the survival of the microcrustacean Mysidopsis juniae and physicochemical analyses. The evaluation of physiochemical parameters revealed a decrease in dissolved oxygen content in the rainy season. However, there was a significant reduction in microcrustacean survival in samples during the dry season, when the river flow is reduced and effluents become concentrated. These results suggest that pollutants received and carried by the waters of the Poxim River contribute to the reduction of environmental quality in the estuary, and this impact may vary according to dry and rainy patterns, that are uncertain considering the impacts of climate change on tropical regions.


Assuntos
Ecotoxicologia/métodos , Estuários , Rios/química , Qualidade da Água/normas , Análise de Variância , Animais , Brasil , Crustáceos/fisiologia , Valores de Referência , Águas Salinas , Estações do Ano , Estatísticas não Paramétricas , Temperatura Ambiente , Poluição da Água
16.
Artigo em Inglês | MEDLINE | ID: mdl-30576801

RESUMO

Crustacean growth is characterized by molting, whereby the old exoskeleton is shed and replaced by a new and larger version. The cellular events that lead to molting are driven by steroid hormones (ecdysteroids) secreted by paired endocrine glands (Y-organs). Between molts, ecdysteroid production is suppressed by a polypeptide molt-inhibiting hormone (MIH) released from neurosecretory cells in the eyestalks. Although a decrease in the MIH titer precedes the upsurge in ecdysteroidogenesis, it is hypothesized that a positive regulatory signal is also required for full activation of Y-organs. Existing data point to an intracellular Ca2+ signal. Ca2+ signaling is dependent on a tightly regulated Ca2+ gradient, achieved through membrane transport proteins. One such protein, the sarco/endoplasmic reticulum Ca2+ ATPase (SERCA), pumps Ca2+ from cytosol to the lumen of the ER. We have recently cloned from Y-organs of the blue crab (Callinectes sapidus) a cDNA encoding a putative Cas-SERCA protein. In studies reported here, quantitative PCR (QPCR) was used to quantify Cas-SERCA transcript abundance in Y-organs during a molting cycle, and radioimmunoassay was used to quantify ecdysteroids in hemolymph. The abundance of the Cas-SERCA transcript in Y-organs increased gradually during pre-molt. Similarly, the level of ecdysteroids in hemolymph increased during pre-molt. The results are consistent with the hypothesis that Cas-SERCA functions to maintain Ca2+ homeostasis in Y-organs. Cas-SERCA transcript abundance also changed in several non-ecdysteroidogenic tissues during a molting cycle. The pattern of change differed among tissues suggesting a functional role for SERCA in each.


Assuntos
Proteínas de Artrópodes/genética , Crustáceos/fisiologia , Ecdisteroides/metabolismo , Hemolinfa/metabolismo , Muda , RNA Mensageiro/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Animais , Crustáceos/enzimologia , Derme/metabolismo , Hepatopâncreas/metabolismo , Músculos/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-30463042

RESUMO

The swimming crab (Portunus trituberculatus, Portunus) can tolerate low salinity, but the mechanism of its varied salinity adaptation at the molecular level remains unclear. In this study, we prepared four mRNA and microRNA (miRNA) libraries using the gills collected from four salinity groups and performed RNA-sequencing (RNA-Seq) to identify the genes related to the low salinity. We set 25 ppt as the control group. A total of 659 genes were differentially expressed in at least one of the six comparison groups (25 ppt vs. 20 ppt, 25 ppt vs. 15 ppt, 25 ppt vs. 10 ppt, 20 ppt vs. 15 ppt, 20 ppt vs. 10 ppt and 15 ppt vs. 10 ppt). A total of 15 and 9 unigenes were downregulated and upregulated under low salinity compared with that in 25 ppt, respectively. Six genes, namely, aminopeptidase, centromere protein, cytochrome b5 reductase, bone morphogenetic protein, and two carbonic anhydrases, were selected for verification through quantitative real-time PCR. The results were consistent with the RNA-Seq results. Furthermore, 95 conserved miRNAs and 16 novel miRNAs were differentially expressed in at least one of the six comparison groups. Analysis of the miRNA-mRNA interaction showed that miR-2 and miR-317 regulated >50 mRNA targets. In addition, let-7c was downregulated in all groups under low salinity compared with that in the control group. This study helped elucidate the adaptation mechanism of the swimming crab in low-saline environments.


Assuntos
Proteínas de Artrópodes/genética , Crustáceos/fisiologia , Brânquias/fisiologia , Salinidade , Estresse Fisiológico , Transcrição Genética/fisiologia , Adaptação Fisiológica/genética , Animais , Feminino , Perfilação da Expressão Gênica , Reação em Cadeia da Polimerase em Tempo Real
18.
J Therm Biol ; 78: 140-150, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30509630

RESUMO

In intertidal marine crustaceans, phenotypic variation in physiological and life-history traits is pervasive along latitudinal clines. However, organisms have complex phenotypes, and their traits do not vary independently but rather interact differentially between them, effect that is caused by genetic and/or environmental forces. We evaluated the geographic variation in phenotypic integration of three marine crab species that inhabit different vertical thermal microhabitats of the intertidal zone. We studied seven populations of each species along a latitudinal gradient that spans more than 3000 km of the Chilean coast. Specifically we measured nine physiological traits that are highly related to thermal physiology. Of the nine traits, we selected four that contributed significantly to the observed geographical variation among populations; this variation was then evaluated using mixed linear models and an integrative approach employing machine learning. The results indicate that patterns of physiological variation depend on species vertical microhabitat, which may be subject to chronic or acute environmental variation. The species that inhabit the high- intertidal sites (i.e., exposed to chronic variation) better tolerated thermal stress compared with populations that inhabit the lower intertidal. While those in the low-intertidal only face conditions of acute thermal variation, using to a greater extent the plasticity to face these events. Our main results reflect that (1) species that inhabit the high-intertidal maintain a greater integration between their physiological traits and present lower plasticity than those that inhabit the low-intertidal. (2) Inverse relationship that exists between phenotypic plasticity and phenotypic integration of the physiological traits identified, which could help optimize energy resources. In general, the study of multiple physiological traits provides a more accurate picture of how the thermal traits of organisms vary along temperature gradients especially when exposed to conditions close to tolerance limits.


Assuntos
Aclimatação , Temperatura Corporal , Crustáceos/fisiologia , Ecótipo , Animais , Crustáceos/genética , Aprendizado de Máquina
19.
Environ Sci Pollut Res Int ; 25(34): 34306-34318, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30293103

RESUMO

Microbiological impact is critical in coastal areas where tourism is particularly important for both the local and regional economy. Submarine outfalls are commonly used to enhance the dispersion of treated sewage thus avoiding pollution along the coast. The Venice lagoon (North Italy) has a very sensitive ecosystem, due to the morphological and natural characteristics of the basin and the co-existence of human activities. To preserve the lagoon, the discharge from the treatment plant for urban wastewater collected from the Venezia-Mestre agglomeration, neighbouring areas and local industries (total of 400,000 population equivalent-PE) has been moved from the lagoon to the open Adriatic Sea since November 2013 by means of an approximately 20-km pipeline. Microbiological pollution inside the lagoon can affect shellfish breeding areas instead, along the coast it affects the quality of bathing waters. In this study, and for the first time, a 3D hydrodynamic SHYFEM model (shallow water finite element model) with high spatial resolution coupled with a microbiological module has been applied to the lagoon and to the Adriatic Sea, to evaluate the effectiveness of the location of the submarine outfall. Microbiological data have been produced by the control Authority according to official analytic methods and by the plant operator. The module of survival of free Escherichia coli follows a variable rate in dependence of UV radiation, temperature and salinity in the water. Two scenarios were modelled: final discharge into the lagoon before November 2013 and after into the open sea. In the latter case, two situations have been considered, one with "Bora" and the other with "Scirocco" winds. Our results indicate that the model correctly simulates microbiological decay and dispersion. The transferral of the final discharge point far from the shoreline improves pollution dispersion, thus preserving the lagoon without evidence of impacts on the bathing waters in all meteorological conditions.


Assuntos
Técnicas de Apoio para a Decisão , Instalações de Eliminação de Resíduos , Águas Residuárias/microbiologia , Animais , Crustáceos/fisiologia , Ecossistema , Monitoramento Ambiental , Escherichia coli , Hidrodinâmica , Itália , Salinidade , Água do Mar/microbiologia , Temperatura Ambiente , Raios Ultravioleta , Eliminação de Resíduos Líquidos , Microbiologia da Água , Vento
20.
Elife ; 72018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30325308

RESUMO

The Large Cell (LC) motor neurons of the crab cardiac ganglion have variable membrane conductance magnitudes even within the same individual, yet produce identical synchronized activity in the intact network. In a previous study we blocked a subset of K+ conductances across LCs, resulting in loss of synchronous activity (Lane et al., 2016). In this study, we hypothesized that this same variability of conductances makes LCs vulnerable to desynchronization during neuromodulation. We exposed the LCs to serotonin (5HT) and dopamine (DA) while recording simultaneously from multiple LCs. Both amines had distinct excitatory effects on LC output, but only 5HT caused desynchronized output. We further determined that DA rapidly increased gap junctional conductance. Co-application of both amines induced 5HT-like output, but waveforms remained synchronized. Furthermore, DA prevented desynchronization induced by the K+ channel blocker tetraethylammonium (TEA), suggesting that dopaminergic modulation of electrical coupling plays a protective role in maintaining network synchrony.


Assuntos
Crustáceos/fisiologia , Dopamina/metabolismo , Gânglios/fisiologia , Junções Comunicantes/metabolismo , Neurônios Motores/fisiologia , Potenciais de Ação , Animais , Gânglios/efeitos dos fármacos , Neurônios Motores/efeitos dos fármacos , Técnicas de Patch-Clamp , Serotonina/metabolismo
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