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1.
Fish Shellfish Immunol ; 99: 154-166, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32045638

RESUMO

We evaluated the effects of hesperidin on the nonspecific immunity, antioxidant capacity and growth performance of red swamp crayfish (Procambarus clarkii). A total of 900 healthy crayfish were randomly divided into six groups: the control group (fed the basal diet) and the HES25, HES50, HES75, HES100 and HES150 groups, which were fed the basal diet supplemented with 25, 50, 75, 100 and 150 mg kg-1 hesperidin, respectively. The feeding experiment lasted 8 weeks. The results indicated that compared with the control group, the crayfish groups supplemented with 50-150 mg kg-1 hesperidin had a decreased feed conversion ratio (FCR) and increased final body weight (FBW), specific growth rate (SGR) and weight gain (WG) (P < 0.05). The protein carbonyl content (PCC), reactive oxygen species (ROS) level and malondialdehyde (MDA) level in the hepatopancreas and hemocytes were significantly lower, while the total antioxidant capacity (T-AOC), glutathione peroxidase (GPx) activity, and superoxide dismutase (SOD) activity were significantly higher in the crayfish groups supplemented with 50-150 mg kg-1 hesperidin than in the control group. Supplementation with 50-150 mg kg-1 hesperidin significantly increased the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LZM), and phenoloxidase (PO) compared with the control group (P < 0.05); upregulated the mRNA expression of cyclophilin A (CypA), extracellular copper-zinc superoxide dismutase (ecCuZnSOD), GPxs, crustin, astacidin, Toll3 and heat shock protein 70 (HSP70) (P < 0.05); and decreased crayfish mortality following white spot syndrome virus (WSSV) infection. These findings indicate that dietary hesperidin supplementation at an optimum dose of 50-150 mg kg-1 may effectively improve nonspecific immunity, antioxidant capacity and growth performance in crayfish.


Assuntos
Astacoidea/crescimento & desenvolvimento , Astacoidea/imunologia , Infecções por Vírus de DNA/veterinária , Suplementos Nutricionais , Resistência à Doença , Hesperidina/imunologia , Ração Animal , Animais , Antioxidantes/metabolismo , Infecções por Vírus de DNA/imunologia , Hemócitos/imunologia , Hepatopâncreas/imunologia , Hesperidina/administração & dosagem , Imunidade Inata , Vírus da Síndrome da Mancha Branca 1
2.
Fish Shellfish Immunol ; 96: 122-125, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31805411

RESUMO

This study aims to investigate the effects of replacing different proportions of fishmeal with Antarctic krill (AK) on the growth performance, body composition and nonspecific immunity index of red swamp crayfish Procambarus clarkia. AK was used to replace 0 (control), 25%, 50% and 100% of the fishmeal in the basic diet of crayfish to formulate four test feeds with basically equivalent nitrogen and lipid contents; these feeds were denoted AK0, AK25, AK50 and AK100, respectively. Compared with the control group, crayfish fed diets with AK replacement showed increased body weight gain; feed efficiency; survival rate; body protein content; phenoloxidase, superoxide dismutase and glutathione peroxidase activities; total haemocyte counts; number of hyaline, semigranular and granular cells; and disease resistance against Aeromonas hydrophila. Conversely, the body lipid level of these crayfish decreased relative to that of the control. However, a high AK level (AK100) does not show improvements in efficiency compared with a moderate AK level (AK50). Based on the efficiency of AK in enhancing the growth performance and nonspecific immunity of crayfish, the optimum replacement proportion of fishmeal with AK was 50%. These results confirm that AK can promote the growth of crayfish and improve their disease resistance.


Assuntos
Astacoidea/crescimento & desenvolvimento , Astacoidea/imunologia , Euphausiacea/química , Imunidade Inata , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Astacoidea/efeitos dos fármacos , Astacoidea/microbiologia , Dieta , Relação Dose-Resposta a Droga , Imunidade Inata/efeitos dos fármacos , Distribuição Aleatória
3.
Mol Genet Genomics ; 295(2): 299-311, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31724065

RESUMO

The red claw crayfish (Cherax quadricarinatus) is an emerging and important commercial species in several countries, and is also a potential biological model in crustacean biology. However, its molecular embryonic development mechanism remains largely unknown because of a lack of genomic resources and systematic research. A comprehensive and integrated transcriptomic analysis is necessary to reveal the cell biological function, gene expression profiles, and embryo patterning that occur during embryogenesis. In the present study, transcriptomic profiles of C. quadricarinatus embryos during three developmental stages were investigated by high-throughput Illumina sequencing technology, and the genes related to development were further analyzed. In total, 49,436 unigenes were assembled and clustered, in which 13,727 were annotated in the Nonredundant database, 5087 were classified based on Gene Ontology annotations, and 2735 were associated with 189 Kyoto Encyclopedia of Genes and Genomes pathways. Furthermore, gene expression differences among the embryos stages were analyzed, and 6658 differentially expressed genes (DEGs) were identified. In total, 3300, 5211, and 1262 DEGs were identified between the eye pigments forming stage (EP) and prepare-hatching stage (PH), EP and larvae (L), as well as PH and L; meanwhile, 1595, 2540 and 680 DEGs were annotated, respectively. The fundamental developmental genes related to apoptosis, neurogenesis, and segmentation, as well as signaling pathways related to Hedgehog, MAPK, Wnt, TGF-ß and Notch, showed higher expression during the EP stage than in other two stages, indicating that the EP stage has more active biological processes than the latter stages. This transcriptome studies gene expression at different stages of embryonic development and the datasets provide a basis for understanding crustacean developmental biology and guiding seedling production.


Assuntos
Astacoidea/genética , Desenvolvimento Embrionário/genética , Imunidade Inata/genética , Transcriptoma/genética , Animais , Proteínas de Artrópodes/genética , Astacoidea/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Anotação de Sequência Molecular
4.
Artigo em Inglês | MEDLINE | ID: mdl-31472239

RESUMO

Molt-inhibiting hormone (MIH), a neuropeptide synthesized in the eyestalk in crustaceans, is mainly responsible for the molting by negatively controlling the ecdysteroids secretion. Although there are several reports of the isolation and protein sequencing of MIH in the red swamp crayfish, little is known about the nucleotide sequence and gene organization of this neuropeptide, even less about the association of MIH polymorphisms and growth traits. Here, a 1237 bp full-length MIH cDNA was obtained from the crayfish eyestalk, which encodes a putative protein of 106 amino acids, with a 191 bp 5'-UTR and a 728 bp 3'-UTR. The MIH genomic DNA sequence is 4205 bp in length, which includes three exons interrupted by two introns, and a 929 bp 5'-flanking region. Potential transcription initiation site and transcription factor binding sites were identified in the 5'-flanking region, implying a potential role in transcriptional regulation. Seventeen SNPs in the 5'-flanking region and 3'-UTR were identified, and the associations between these SNPs and growth traits were evaluated with a two-stage design. A SNPs g. -12C > G that showed a significant association with body weight was identified. Individuals with GG genotype had a significantly higher body weight than those with CC genotype (43.98 ±â€¯9.82 g vs. 34.27 ±â€¯6.87 g; P ﹤ 0.001), indicating a beneficial effect of the G allele on the growth of red swamp crayfish. The obtained MIH gene, as well as the identified SNPs, may serve as targets for molecular marker-aided selection in growth improvement of the red swamp crayfish in future studies.


Assuntos
Astacoidea/crescimento & desenvolvimento , Astacoidea/metabolismo , Hormônios de Invertebrado/genética , Hormônios de Invertebrado/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Animais , Astacoidea/genética , Peso Corporal/genética , Peso Corporal/fisiologia , Éxons/genética , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/fisiologia , Genótipo , Hormônios de Invertebrado/química
5.
Biochem Biophys Res Commun ; 517(3): 458-462, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31376940

RESUMO

Cyclin B is a ubiquitous regulatory molecule and has been implicated in mitosis and meiosis in oocytes. Phenomenon that differ in the length of cyclin B 3'UTR in crustacean has attracted much attention, although molecular details are poorly understood. The study of 3'UTR-interacting proteins could yield much information in translational regulation and the mRNA localization process. Previous studies on crayfish suggested that the 3'UTR (1300 bp) probably contains the potential regulatory sequence/motifs such as CPEs and K-box et al. In present study, using pull-down assay coupled with mass spectrometry approach allowing us to explore the potential proteins associated with the 3'UTR. We finally identified four candidate proteins including Hspg 2, Vtg, eef1a and Tuba1a, which annotated as significant roles involved in cell differentiation, lipid transporter activity, and meiotic cell cycle process. The preliminary results will contribute to the advance in understanding the translational activation of cyclin B in oocyte maturation regulation in crustacean.


Assuntos
Regiões 3' não Traduzidas , Proteínas de Artrópodes/genética , Astacoidea/genética , Ciclina B/genética , Regulação da Expressão Gênica no Desenvolvimento , Oócitos/metabolismo , Animais , Proteínas de Artrópodes/metabolismo , Astacoidea/citologia , Astacoidea/crescimento & desenvolvimento , Astacoidea/metabolismo , Transporte Biológico , Ciclina B/metabolismo , Feminino , Proteoglicanas de Heparan Sulfato/genética , Proteoglicanas de Heparan Sulfato/metabolismo , Meiose , Oócitos/citologia , Oócitos/crescimento & desenvolvimento , Oogênese/genética , Fator 1 de Elongação de Peptídeos/genética , Fator 1 de Elongação de Peptídeos/metabolismo , Ligação Proteica , Biossíntese de Proteínas , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Vitelogeninas/genética , Vitelogeninas/metabolismo
6.
Fish Shellfish Immunol ; 93: 796-800, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31422177

RESUMO

This study aims to investigate the effects of Rhodiola rosea polysaccharide (RRP) on the growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkia. RRP was prepared by hot water extraction and partly characterised by high-performance liquid chromatography and sugar composition analyses. Three diets supplemented with three different levels of RRP (0.2, 0.6 and 1 g kg diet-1) were formulated and tested for growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkii, while a diet without any RRP supplementation served as control. After 8 weeks of feeding, body weight gain, feed efficiency, survival rate, phenoloxidase activity, superoxide dismutase activity, glutathione peroxidase level, total haemocyte count and number of hyaline cells, semigranular cells and granular cells and resistance to Aeromonas hydrophila were higher than those of the control. Moreover, based on the efficiency of RRP on the growth performance and nonspecific immunity of crayfish, the optimum dose of RRP was found to be 0.6 g kg diet-1. Hence, intake of diets containing RRP could enhance the growth performance, immune responses and improve resistance of crayfish to infection by A. hydrophila.


Assuntos
Astacoidea/imunologia , Carboidratos da Dieta/farmacologia , Imunidade Inata/efeitos dos fármacos , Polissacarídeos/farmacologia , Rhodiola/química , Ração Animal/análise , Animais , Astacoidea/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Distribuição Aleatória
7.
Genes (Basel) ; 10(9)2019 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-31455039

RESUMO

The androgenic gland (AG) is a male-specific endocrine organ that controls the primary and secondary sexual characteristics in male crustaceans. More evidence indicates that the insulin-like androgenic gland hormone gene (IAG) is the key male sexual differentiation factor, particularly the application of RNA interference (RNAi) technology on IAG. In this study, the full-length cDNA of IAG (termed PcIAG) was isolated from the red swamp crayfish, Procambarus clarkii. Tissue distribution analysis showed that in addition to its expression in the AG of male P. clarkii, PcIAG was widely expressed in female tissues and other male tissues. The PcIAG protein was detected in the reproductive and nervous systems of adult male P. clarkii. Additionally, RNAi results showed that the PcIAG expression could be silenced efficiently, and the male sperm maturation and release possibly present a transient adverse interference at lower doses (0.1 µg/g and 1 µg/g) of PcIAG-dsRNA (PcIAG double-stranded RNA). Dramatically, the expression level of PcIAG increased sharply shortly after the injection of higher doses (5 µg/g and 10 µg/g) of PcIAG-dsRNA, which might accelerate the maturation and release of sperm. Moreover, the expression of PcSxl (P. clarkii Sex-lethal) was detected by Quantitative Real-Time PCR (qPCR) after the injection of PcIAG-dsRNA to explore whether the PcIAG gene regulates the PcSxl gene, and we found that the PcIAG did not directly regulate PcSxl in P. clarkii. The study could help accelerate the progress of PcIAG functional research and provide a useful reference for the single-sex selective breeding of P. clarkii.


Assuntos
Astacoidea/genética , Hormônios Gonadais/genética , Diferenciação Sexual , Animais , Astacoidea/crescimento & desenvolvimento , Astacoidea/metabolismo , Glândulas Endócrinas/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genitália/metabolismo , Hormônios Gonadais/metabolismo , Masculino , Sistema Nervoso/metabolismo , Espermatogênese
8.
Arch Environ Contam Toxicol ; 77(3): 452-460, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31451889

RESUMO

The adoption of genetically modified (GM) crops has occurred rapidly in the United States. The transfer of GM corn byproducts from agricultural fields to nearby streams after harvest is significant and occurs well into the post-harvest year. These corn leaves, stems, and cobs then become a detrital food source for organisms, such as shredders in the stream ecosystem. Considering that the nontarget effects of Bt corn have been observed in some terrestrial organisms, we assessed whether Bt toxins affect an important aquatic organism, juvenile F. rusticus crayfish. Juvenile crayfish were fed six distinct diet treatments: two varieties of Bt corn, two non-Bt controls of herbicide tolerant corn, and two controls: fish gelatin and river detritus. Juveniles were fed these diets while housed in flow-through artificial streams that received natural stream water from a local source. Specific growth rate and survivorship of the crayfish were measured throughout the study. Juveniles fed corn diets grew significantly less and had reduced survival compared with juveniles fed fish gelatin or river detritus diets. Furthermore, juveniles fed one Bt variety of corn (VT Triple Pro®) exhibited significantly less growth than those fed one of the herbicide tolerant varieties (Roundup Ready 2®). Our study shows that corn inputs to streams may be detrimental to the growth and survivorship of juvenile crayfish and that certain Bt varieties may exacerbate these negative effects. These effects on crayfish will have repercussions for the entire ecosystem, because crayfish are conduits of energy between many trophic levels.


Assuntos
Ração Animal/efeitos adversos , Astacoidea/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/toxicidade , Zea mays/genética , Animais , Astacoidea/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/toxicidade , Produtos Agrícolas , Ecossistema , Endotoxinas/genética , Endotoxinas/toxicidade , Gelatina/farmacologia , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/toxicidade , Folhas de Planta/genética , Rios
9.
Int J Biol Macromol ; 137: 177-186, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31255619

RESUMO

Gracilaria is a genus of red algae widely cultivated in Asia and is notable for its economic importance as food ingredients. Neoagaro oligosaccharides (NAOSs) are products of Gracilaria that have excellent water solubility, antioxidant activity and prebiotic effect. In this study, Gracilaria crude polysaccharide was treated with agarase and hydrolyzed into NAOSs with different degrees of polymerization (DP). The compositions of the hydrolyzed NAOSs were analyzed by electrospray ionization-time of flight-mass spectrometry and thin layer chromatography. The antioxidant capacity and prebiotic effects of NAOSs with different DPs were investigated and the results showed that DP could affect the antioxidant capacity of NAOSs. The prebiotic effects of NAOSs with different DP were evaluated based on the influence on the growth of four intestinal bacteria. NAOSs promoted the growth of Lactobacillus delbrueckii subsp. bulgaricus and Sterptococcus thermophilus. The protective effect of Gracilaria NAOSs in simulated gastrointestinal juice was also studied. Finally, NAOSs with best prebiotic effects were used in Procambarus feeding experiment and exhibited promotion effect on Procambarus growth. The present study showed that Gracilaria NAOSs can be utilized as antioxidant and prebiotic additive, which had a considerable potential in food and feed industry.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Glicosídeo Hidrolases/metabolismo , Gracilaria/química , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Prebióticos , Animais , Antioxidantes/metabolismo , Astacoidea/efeitos dos fármacos , Astacoidea/crescimento & desenvolvimento , Biomimética , Indústria Alimentícia , Trato Gastrointestinal/metabolismo , Hidrólise , Oligossacarídeos/metabolismo
10.
Aquat Toxicol ; 213: 105222, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31212248

RESUMO

Pharmaceutically active compounds are major contaminants of aquatic environments that show direct and indirect effects on aquatic organisms even at low concentrations. The aim of this study was to assess the effects of the illicit drug methamphetamine and the antidepressant sertraline on clonal marbled crayfish Procambarus virginalis. Crayfish exposed to the environmentally relevant concentrations of methamphetamine of ∼1 µg L-1 did not exhibit significant differences from unexposed controls in distance moved, velocity, and activity level with or without available shelter. Sertraline-exposed (∼1 µg L-1) crayfish were significantly more active, regardless of available shelter, and moved greater distances when shelter was available, compared to control crayfish. Crayfish exposed to methamphetamine and sertraline spent significantly more time outside the shelters compared to controls. Sertraline-exposed crayfish spawned more frequently and showed higher mortality than controls. The results suggest that the low environmental concentrations of the tested compounds could alter the behavior and life history traits of crayfish, resulting in higher reproductive effort and mortality.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/crescimento & desenvolvimento , Astacoidea/efeitos dos fármacos , Astacoidea/crescimento & desenvolvimento , Comportamento Animal/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Metanfetamina/toxicidade , Sertralina/toxicidade , Animais , Invertebrados , Poluentes Químicos da Água/toxicidade
11.
Fish Shellfish Immunol ; 88: 28-35, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30826415

RESUMO

Hemocytes are the major immune cells of crustaceans. New hemocyte production is required throughout the life cycle of these animals to maintain a functional immune system. The mechanism of crustacean hematopoiesis has just begun to be understood and new methods are needed for the investigation of this process. Here we report the directed differentiation of granular cells (GCs) from the hematopoietic tissue (HPT) cells of Cherax quadricarinatus in vitro. We started by providing the cultured HPT cells with different additives to induce possible differentiation. We found that crayfish muscle extract greatly promoted the physical status of the cells and induced the formation of refractile cytoplasmic granules. The transcription of marker genes and the production of functional prophenoloxidase further confirmed the formation of mature GCs. In our experiments, young GCs usually started to develop in ∼2 weeks post induction and over 60% of the cells became mature within 3-4 weeks. This is the first time that the fully differentiation of crustacean hemocytes is accomplished in vitro. It provides a powerful tool for in-depth study of crustacean hematopoiesis.


Assuntos
Astacoidea/crescimento & desenvolvimento , Hemócitos/citologia , Animais , Astacoidea/citologia , Catecol Oxidase/metabolismo , Diferenciação Celular , Células Cultivadas , Precursores Enzimáticos/metabolismo , Hematopoese , Técnicas In Vitro , Masculino , Músculos/química
12.
Environ Sci Pollut Res Int ; 26(12): 11710-11718, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30806926

RESUMO

Great efforts have been devoted to assessing the effects of straw managements on greenhouse gas (GHG) emissions, global warming potential (GWP), and net economic budget in rice monoculture (RM). However, few studies have evaluated the effects of straw managements on GHG emissions and net ecosystem economic budget (NEEB) in integrated rice-crayfish farming (RC). Here, a randomized block field experiment was performed to comprehensively evaluate the effects of aquatic breeding practices (feeding or no feeding of forage) and straw managements (rice straw returning or removal) on soil NH4+-N and NO-3-N contents, redox potential (Eh), CH4 and N2O emissions, GWP, and NEEB of fluvo-aquic paddy soil in a rice-crayfish co-culture system in Jianghan Plain of China. We also compared the differences in CH4 and N2O emissions, GWP, and NEEB between RM and RC. Straw returning significantly increased CH4 and N2O emissions by 34.9-46.1% and 6.2-23.1% respectively compared with straw removal. Feeding of forage decreased CH4 emissions by 13.9-18.7% but enhanced N2O emissions by 24.4-33.2% relative to no feeding. Compared with RM treatment, RC treatment decreased CH4 emissions by 18.1-19.6% but increased N2O emissions by 16.8-21.0%. Moreover, RC treatment decreased GWP by 16.8-22.0% while increased NEEB by 26.9-75.6% relative to RM treatment, suggesting that the RC model may be a promising option for mitigating GWP and increasing economic benefits of paddy fields. However, the RC model resulted in a lower grain yield compared with the RM model, indicating that more efforts are needed to simultaneously increase grain yield and NEEB and decrease GWP under RC model.


Assuntos
Agricultura/métodos , Astacoidea/crescimento & desenvolvimento , Gases de Efeito Estufa/análise , Oryza/crescimento & desenvolvimento , Agricultura/estatística & dados numéricos , Animais , Aquicultura/métodos , Aquicultura/estatística & dados numéricos , China , Ecossistema , Fazendas , Aquecimento Global , Metano/análise , Óxido Nitroso/análise , Solo
13.
Bull Environ Contam Toxicol ; 102(3): 365-370, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30656355

RESUMO

The aim of this study was to examine fertility of spiny-cheek crayfish harvested in the first half of April from the Vistula Lagoon and to compare it with that of the crayfish from freshwater habitats. The sample consisted of 47 sexually mature females shortly before they were ready to lay eggs. After determining the absolute fertility (number of eggs per ovary), the relative fertility was calculated (number of eggs per 1 g of body weight). Absolute and relative fertility of spiny-cheek crayfish females with total body length 8.1-11.6 cm was 535 and 17 eggs, respectively. Absolute and relative fertility was correlated with total body length and weight. Along with the increase in these parameters, the absolute fertility increased and the relative fertility decreased. A comparison of absolute and relative fertility of spiny-cheek crayfish from the Vistula Lagoon with the representatives of this species from freshwater habitats such as the Brda River and the Lake Dgal Wielki, showed no significant differences.


Assuntos
Astacoidea/fisiologia , Monitoramento Ambiental/métodos , Fertilidade/fisiologia , Rios/química , Água do Mar/química , Animais , Astacoidea/crescimento & desenvolvimento , Peso Corporal/fisiologia , Ecossistema , Eutrofização , Feminino , Polônia , Salinidade
14.
J Exp Biol ; 222(Pt 2)2019 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-30530836

RESUMO

The molting process of arthropods, chiefly controlled by ecdysteroids, is generally considered very stressful. Our previous investigations have shown that crayfish, after having experienced stressful situations, display anxiety-like behavior (ALB), characterized by aversion to light in a dark/light plus-maze (DLPM). In the present experiments, the spontaneous exploratory behavior of isolated crayfish was analyzed in a DLPM at different stages of their molt cycle. All tested animals displayed transitory aversion to light similar to ALB, before and, mostly, after molting, but not during inter-molt. Injection of ecdysteroids into inter-molt animals elicited ALB after a delay of 4 days, suggesting a long-term, possibly indirect, hormonal effect. Importantly, ecdysteroid-induced ALB was suppressed by the injection of an anxiolytic benzodiazepine. Thus, molts and their hormonal control impose internal stress on crayfish, leading to aversion behavior that has the main characteristics of anxiety. These observations are possibly generalizable to many other arthropods.


Assuntos
Astacoidea/fisiologia , Muda , Animais , Ansiolíticos/administração & dosagem , Astacoidea/efeitos dos fármacos , Astacoidea/crescimento & desenvolvimento , Astacoidea/efeitos da radiação , Benzodiazepinas/administração & dosagem , Comportamento Exploratório/fisiologia , Comportamento Exploratório/efeitos da radiação , Luz , Masculino
15.
Behav Processes ; 157: 204-207, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30287274

RESUMO

1. Aquatic invertebrates commonly disperse between waterbodies by flight, though some decapods can emigrate from the water and walk overland. 2. The signal crayfish (Pacifastacus leniusculus, Dana) is a highly invasive species that can survive for days to weeks out of water, though it is unclear to what extent vulnerable life stages, such as ovigerous females or juvenile crayfish, terrestrially emigrate. Understanding this behaviour is important to consider during the management of crayfish stocks, since a single ovigerous female could potentially introduce hundreds of hatchlings to a new waterbody, which could themselves disperse overland. 3. Here, in a laboratory study, we examined the terrestrial emigration tendency of juvenile crayfish and compared the terrestrial emigration behaviour and overland walking speed of ovigerous and non-ovigerous females. 4. Size had a significant influence on juvenile crayfish terrestrial emigration tendency, where only those larger than 16.6 mm (carapace length) left the water. Ovigerous and non-ovigerous female signal crayfish showed no significant difference in terrestrial emigration tendency nor overland walking speed. 5. This is the first study to directly examine the terrestrial emigration behaviour of crayfish during these different life stages. These findings highlight the importance of considering animal behaviour during management strategies.


Assuntos
Migração Animal , Astacoidea/crescimento & desenvolvimento , Espécies Introduzidas , Distribuição Animal , Animais , Ecossistema , Feminino
16.
Fish Shellfish Immunol ; 83: 158-161, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30195902

RESUMO

An eight-week experiment was conducted to determine the effects of dietary fulvic acids (FAs) on the growth performance, digestive enzymes and nonspecific immunity of red swamp crayfish Procambarus clarkia. Three diets supplemented with three different levels of FAs (0.1, 0.5 and 1 g kg-1) were formulated and tested for the growth performance, digestive enzymes and nonspecific immunity of the crayfish, and a diet without FAs served as control. After eight weeks of feeding, survival rate, phenoloxidase activity, superoxide dismutase activity, glutathione peroxidase level, total haemocyte count and number of hyaline cells, semigranular cells and granular cells and resistance to Aeromonas hydrophila of crayfishes fed with FA-containing diets were higher than those of the control. Moreover, based on the efficiency of FAs on the growth performance and nonspecific immunity of crayfish, the optimum dose of FAs was found to be 0.5 g (kg diet)-1. A high level of FA administration (1 g kg-1) did not further increase the efficiency of FAs compared with those in the moderate group (0.5 g kg-1, p > 0.05). Results indicated that oral administration of FA-containing diets can enhance the growth performance, intestinal digestive enzymes, immune responses and resistance of crayfish to infection by A. hydrophila. Thus, FAs may be utilized as a diet supplement for crayfish.


Assuntos
Astacoidea , Benzopiranos/administração & dosagem , Peso Corporal , Suplementos Nutricionais/análise , Administração Oral , Ração Animal/análise , Animais , Antioxidantes/administração & dosagem , Astacoidea/crescimento & desenvolvimento , Astacoidea/imunologia , Fenômenos Fisiológicos do Sistema Digestório , Doenças dos Peixes/imunologia , Imunidade Inata
17.
Environ Monit Assess ; 190(9): 559, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30159631

RESUMO

Invasive species are one of the main threats to biodiversity. When an alien species is introduced into a new environment, fast identification and definition of management strategies may avoid or minimize impacts. When an invasive species is already established, the most adopted approaches are population control and monitoring. In order to perform such strategies, assessment of characteristics of the invasive population is imperative. This study tested a new method of population size estimation and monitoring in an invasive population of crayfish Procambarus clarkii in a conservation area in the Atlantic Rain Forest (Southeastern Brazil). The population dynamics was studied for 1 year to examine the efficacy of the selected method and to evaluate if the population is stable. Later, the effect of periodical removal of animals on the population size was tested. The method of population estimation used in this study proved to be very effective. We recommend using it to monitor invasive populations of P. clarkii. The population size varied discretely over the year with variable but low growth rate, indicating that the population is already established which introduce a notable threat to native species. The continuous removal of specimens proved to be inefficient since the growth rate was higher after the removal. One intensive removal event might be more effective than a continuous moderate removal as the one applied in this study.


Assuntos
Astacoidea/crescimento & desenvolvimento , Biodiversidade , Monitoramento Ambiental/métodos , Água Doce , Espécies Introduzidas , Animais , Brasil , Densidade Demográfica , Dinâmica Populacional
18.
Toxins (Basel) ; 10(7)2018 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-29973494

RESUMO

This research aimed to study the effects of astaxanthin on energy budget and bioaccumulation of microcystin-leucine-arginine (microcystin-LR) in the crayfish Procambarus clarkii (Girard, 1852). The crayfish (21.13 ± 4.6 g) were cultured under microcystin-LR stress (0.025 mg/L) and were fed with fodders containing astaxanthin (0, 3, 6, 9, and 12 mg/g) for 8 weeks in glass tanks (350 mm × 450 mm × 150 mm). Accumulations of microcystin-LR were measured in different organs of P. clarkii. The results suggested that astaxanthin can significantly improve the survival rate and specific growth rate (SGR) of P. clarkii (p < 0.05). The dietary astaxanthin supplement seems to block the bioaccumulation of microcystin-LR in the hepatopancreas and ovaries of P. clarkii to some extent (p < 0.05). Astaxanthin content of 9⁻12 mg/g in fodder can be a practical and economic choice.


Assuntos
Astacoidea/efeitos dos fármacos , Microcistinas/toxicidade , Animais , Astacoidea/crescimento & desenvolvimento , Astacoidea/metabolismo , Suplementos Nutricionais , Metabolismo Energético/efeitos dos fármacos , Feminino , Hepatopâncreas/metabolismo , Masculino , Toxinas Marinhas , Músculos/metabolismo , Ovário/metabolismo , Espermatozoides/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Xantofilas/farmacologia
19.
Aquat Toxicol ; 200: 217-225, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29775929

RESUMO

Multiple environmental stressors, including nutrient effluents (i.e. nitrates [NO3-]) and altered pH regimes, influence the persistence of freshwater species in anthropogenically disturbed habitats. Independently, nitrate and low pH affect energy allocation by increasing maintenance costs and disrupting oxygen uptake, which ultimately results in impacts upon whole animal performance. However, the interaction between these two stressors has not been characterised. To address this, the effects of nitrate and pH and their interaction on aerobic scope and physiological performance were investigated in the blueclaw crayfish, Cherax destructor. Crayfish were exposed to a 2 × 3 factorial combination, with two pH levels (pH 5.0 and 7.0) and three nitrate concentrations (0, 50 and 100 mg L-1NO3-). Crayfish were exposed to experimental conditions for 65 days and growth and survival were monitored. Aerobic scope (i.e. maximal - standard oxygen uptake) was measured at six time points (1, 3, 5, 7, 14, and 21 days) during exposure to experimental treatments. Crayfish performance was assessed after 28 days, by measuring chelae strength and whole animal activity capacity via the righting response. Survival was reduced in crayfish exposed to pH 5.0, but there was no exacerbation of this effect by exposure to high nitrate levels. Aerobic scope was compromised by the interaction between low pH and nitrate and resulted in prolonged elevations of standard oxygen uptake rates. Exposure to nitrate alone affected aerobic scope, causing a 59% reduction in maximum oxygen uptake. Reduced aerobic capacity translated to reduced chelae strength and righting capacity. Together, these data show that low pH and elevated nitrate levels reduce aerobic scope and translate to poorer performance in C. destructor, which may have the potential to affect organismal fitness in disturbed habitats.


Assuntos
Astacoidea/fisiologia , Nitratos/farmacologia , Animais , Astacoidea/crescimento & desenvolvimento , Fenômenos Biomecânicos , Água Doce , Concentração de Íons de Hidrogênio , Consumo de Oxigênio/efeitos dos fármacos , Análise de Sobrevida , Poluentes Químicos da Água/toxicidade , Qualidade da Água
20.
Anim Reprod Sci ; 193: 153-157, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29673915

RESUMO

Determination and control of spermatozoa quality in crustacean aquaculture is an important issue for successful and controlled reproduction. Investigation of spermatozoa number in spermatophores is a basic and common parameter for determining the reproductive quality in farmed decapods. In the present study, spermatozoa extraction from spermatophores located in the ductus deferens was conducted in Pontastacus leptodactylus using different incubation times and temperatures. The results indicate that the duration of incubation and temperature affected (P < 0.05) spermatozoa extraction. Greater temperatures (40 and 75 °C) resulted in a reduction (P < 0.05) in number of extracted spermatozoa. In contrast, more spermatozoa were extracted when the 4 and 23 °C temperatures were imposed. After 4 h of incubation, the number of extracted spermatozoa were greatest in number at 23 °C. In conclusion, the greater numbers of crayfish spermatozoa can be obtained when the ductus deferens containing spermatophores is incubated at 23 °C for 4 h as compared with other temperatures and incubation durations. The results of present study are useful for assessing spermatozoa quality in aquaculture as well as the extraction of spermatozoa for research purposes.


Assuntos
Aquicultura/métodos , Aquicultura/normas , Astacoidea , Recuperação Espermática , Temperatura , Animais , Astacoidea/crescimento & desenvolvimento , Astacoidea/fisiologia , Calibragem , Água Doce , Masculino , Contagem de Espermatozoides , Motilidade Espermática , Recuperação Espermática/veterinária , Espermatozoides/citologia , Espermatozoides/fisiologia , Fatores de Tempo
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