Growth and reproduction of the lion's paw scallop Nodipecten subnodosus in a suspended culture system at Guerrero Negro lagoon,Baja California Sur,Mexico     

Marcial Arellano‐Martínez  Bertha Patricia Ceballos‐Vázquez  César Ruíz‐Verdugo  Edgar Pérez de León  Rafael Cervantes‐Duarte  Pedro Martin Domínguez‐Valdéz 《Aquaculture Research》2011,42(4):571-582

The lion's paw scallop, Nodipecten subnodosus (Sowerby) has considerable aquacultural potential due to its fast growth and large adductor muscle. Prior investigations throughout northwestern Mexico's littoral have reported highly variable growth rates; furthermore, no studies are available of the environment on growth and gametogenesis in this species under culture conditions. This investigation assesses the effect of food availability and temperature on the growth and gametogenesis of N. subnodosus in a suspended culture system at Guerrero Negro lagoon, Mexico. After 1 year of cultivation, N. subnodosus reached 69.13 mm in shell height (SH) (0.196 mm day^?1, 14 months old). Two significant growth spurts were observed: over the two first months of culture (August and September 2001, mean growth rate 0.4 mm day^?1) and in September 2002 (0.3 mm day^?1), both related to high temperatures and chlorophyll a concentrations. The onset of gametogenesis occurred in April 2002, with an increase in temperature (10‐month‐old scallops, 54.5 mm SH). The first spawning occurred in October and November (86.2 and 93 mm SH), with peak temperatures. These results, together with the analysis of previous reports, indicate that N. subnodosus has a higher preference for temperate areas; therefore, the Guerrero Negro lagoon appears to be a suitable site to culture this species.  相似文献   

Depletion study and estimation of withdrawal periods for florfenicol and florfenicol amine in pacu (Piaractus mesopotamicus)          下载免费PDF全文

Tamires Valim Marques  Jonas Augusto Rizzato Paschoal  Rafael Simões Coelho Barone  José Eurico Possebon Cyrino  Susanne Rath 《Aquaculture Research》2018,49(1):111-119

The intensive production of farmed fish is at a global all‐time high, and the control of bacteria proliferation in fish farms requires the frequent use of antimicrobials. This practice raises important environmental concerns related to the emergence of antimicrobial‐resistant bacteria strains. Only a few antimicrobial drugs have been approved for use in aquaculture, one of which is florfenicol. This work studies the depletion and withdrawal period of florfenicol and its main metabolite, florfenicol amine, in pacu (Piaractus mesopotamicus), a neotropical characin widely farmed in the southern hemisphere. Juvenile pacu (average weight of 724 g) were stocked in a closed‐loop laboratory system with controlled water temperature (25.8°C), and were fed for 10 consecutive days with a diet containing an intended dose of 10 mg/florfenicol per kg bw. Muscle and skin tissues were collected at 1, 3, 6, 8, 10, 12 and 16 days post‐treatment, and florfenicol and florfenicol amine were quantified using a validated ultra‐high performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS) method. The limits of quantitation for florfenicol and florfenicol amine were 10 ng/g in muscle and 50 ng/g in skin. Considering a maximum residue limit of 1000 ng/g for the sum of florfenicol and florfenicol amine in muscle with skin in natural proportions a withdrawal period of 5 days (water temperature 25.8°C) or 129 degree days was calculated on the basis of the upper limit of the one‐sided 95% confidence interval for the 99^th percentile derived from the residue depletion study.  相似文献   

Pedogenic information from fine sand: A study in Mediterranean soils     

Juan M. Martín‐García  Alberto Molinero‐García  Julio Calero  Manuel Snchez‐Maran  María V. Fernndez‐Gonzlez  Rafael Delgado 《European Journal of Soil Science》2020,71(4):580-597

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Assessing seed desiccation responses of native trees in the Caribbean     

Mattana  Efisio  Peguero  Brígido  Di Sacco  Alice  Agramonte  Wilvin  Encarnación Castillo  Wilkin Rafael  Jiménez  Francisco  Clase  Teodoro  Pritchard  Hugh W.  Gómez-Barreiro  Pablo  Castillo-Lorenzo  Elena  Terrero Encarnación  Marianny  Way  Michael J.  García  Ricardo  Ulian  Tiziana 《New Forests》2020,51(4):705-721

New Forests - Native trees from the Caribbean were tested for seed desiccation responses, by adapting the “100-seed test” protocol. Ninety-seven seed lots of 91 species were collected...  相似文献   

Environmental sex determination, external sex differentiation and structure of the androgenic gland in the Pacific white shrimp Litopenaeus vannamei (Boone)     

Rafael Campos-Ramos  Rodolfo Garza-Torres  Danitzia A Guerrero-Tortolero  Alejandro M Maeda-Martínez  & Hortencia Obregón-Barboza 《Aquaculture Research》2006,37(15):1583-1593

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High‐throughput Cryopreservation of Sperm from Sex‐reversed Southern Flounder,Paralichthys lethostigma          下载免费PDF全文

E Hu  Rafael Cuevas‐Uribe  Huiping Yang  Robin Sanderson  Adriane O. Gill  Harry Daniels  Terrence R. Tiersch 《Journal of the World Aquaculture Society》2016,47(4):555-565

The Southern flounder, Paralichthys lethostigma, is a valuable aquaculture fish with established markets in the USA. All‐female production in this species is an important technology for aquaculture because the females usually have body sizes twice those of males at the same age, and sex‐reversed males (genotypic XX neomales) are used for all‐female production by crossing with genetically normal females. However, sperm volume from the neomales is usually small (<0.5 mL) and limits their application for all‐female fish production. Cryopreservation of sperm from these sex‐reversed neomales will provide access on demand with increased efficiency to extend the application of neomales. The goal of this study was to develop a protocol for cryopreservation of sperm from the Southern flounder by using an automated high‐throughput processing system. The objectives were to: (1) determine the effect of osmolality on activation of sperm motility; (2) evaluate the effect of extender solutions on sperm motility capacity; (3) evaluate the acute toxicity of cryoprotectants (dimethyl sulfoxide [DMSO], propylene glycol, and polyethylene glycol) on sperm motility, and (4) estimate the effect of cooling rate on sperm cryopreservation and post‐thaw fertilization. Sperm motility was activated when osmolality was 400 mOsmol/kg or higher. Of the three extender buffers tested, HEPES4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid (HEPES) at 300 mOsmol/kg resulted in better protection for sperm motility than did Hanks' balanced salt solution and Mounib solution at 300 mOsmol/kg during 7 d of refrigerated storage. After 30 min equilibration with the cryoprotectant of 15% DMSO, sperm motility was 24 ± 21% (fresh sperm motility without any cryoprotectants was 42%). After cooling at a rate of 20 C/min, post‐thaw sperm motility was 8 ± 5% and fertilization was 63 ± 40% evaluated at the 32–64 cell stage (5 × 10⁵ sperm per egg). Overall, a protocol was developed for sperm cryopreservation in the Southern flounder with high‐throughput processing, which provides a tool to preserve the valuable genetic resources from neomale flounders, and enables germplasm repository development for the Southern flounder.  相似文献   

Physiological and sanitary condition of the white clam Dosinia ponderosa collected from a coastal area impacted by shrimp farm effluent     

Marcel Martínez-Porchas  Susana Maria Scheuren-Acevedo  Luis Rafael Martínez-Córdova  Teresa Gollas-Galvan  Ramon H. Barraza-Guardado  Fernando Enríquez-Ocaña  Edilmar Cortés-Jacinto  Marco A. Porchas-Cornejo 《Aquaculture International》2016,24(1):243-256

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SDS-PAGE and Western blot of urinary proteins in dogs with leishmaniasis     

Zaragoza C  Barrera R  Centeno F  Tapia JA  Durán E  González M  Mañé MC 《Veterinary research》2003,34(2):137-151

Canine leishmaniasis is an endemic disease in the Mediterranean area caused by the protozoan Leishmania infantum, which usually produces renal failure. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot using antibodies to IgG and IgA from dogs were carried out in the urine of 22 dogs with leishmaniasis diagnosed by ELISA and confirmed by PCR, and 20 healthy dogs. The results were compared to renal function laboratory tests and to those from a histopathological study of the kidneys from sick animals that died naturally or were euthanized. Five different bands with molecular weights ranging from 10 to 110 kDa were obtained from the electrophoresis of the urine of healthy dogs. 33.5% of total proteins corresponded to low molecular weight proteins and the other proteins had middle and high molecular weights. However, in the group with leishmaniasis, a maximum of 11 different bands with molecular weights ranging from 10 kDa to 150 kDa were displayed in the electrophoresis of the urine. The urine electrophoretic pattern in the sick dogs was classified as mixed (proteins with high and low molecular weights) because low molecular weight proteins made up 57.9% and the rest of the proteins had middle and high molecular weights. In Western blot, none of the healthy dogs showed excretion of IgG and/or IgA, whereas IgG and IgA were detected in the Western blot of urine of 68% and 55% respectively of dogs with leishmaniasis. The results obtained in the leishmaniasis group agreed with glomerular and tubular damage, which were confirmed by the histopathological findings.  相似文献   

Herbicide resistance in Aster squamatus conferred by a less sensitive form of acetolactate synthase     

Osuna MD  Fischer AJ  De Prado R 《Pest management science》2003,59(11):1210-1216

A biotype of Aster squamatus (Sprengel) Hieronymus with suspected resistance to the ALS-inhibiting herbicide imazapyr was detected in a chicken farm in the province of Seville, Spain, which had been treated once a year with imazapyr for 10 years. Resistance to imazapyr in this biotype was studied using dose-response experiments, absorption and translocation assays, metabolism studies and ALS activity assays. The rate of imazapyr required to inhibit A squamatus growth by 50% (ED50) was 15 times higher for the R (resistant) than for the S (susceptible) biotype. Cross-resistance existed for the ALS-inhibitors imazamox, imazethapyr, amidosulfuron, nicosulfuron, rimsulfuron, triasulfuron and tribenuron, but not for bensulfuron. Control of A squamatus using alternative herbicides was poor with clopyralid, intermediate with quinclorac, amitrole and MCPA, and excellent with 2,4-D, glufosinate and glyphosate. Absorption of [14C]imazapyr increased over time for both the R and S biotypes, and translocation from the treated leaf to shoots and roots was similar in both biotypes, with most of the radioactivity remaining in the treated leaf. No metabolites of imazapyr were detected in either biotype. Sensitivity of the ALS enzyme (target site) to imazapyr was lower for the R biotype (I50(R) = 4.28 x I50(S)). The mechanism of imazapyr resistance in this R biotype appears to be an altered ALS conferring decreased sensitivity to imazapyr at the whole-plant level.  相似文献   

Evaluation of metabolic detoxifying enzyme activities and insecticide resistance in Frankliniella occidentalis     

Maymó AC  Cervera A  Sarabia R  Martínez-Pardo R  Garcerá MD 《Pest management science》2002,58(9):928-934

The western flower thrips Frankliniella occidentalis (Pergande) is a very significant pest of a number of different agricultural crops in the south-east of Spain. The importance of thrips as a pest is not due mainly to the direct damage inflicted on the plant, but to the loss in commercial value which occurs as a consequence of the development of dark spots caused by the tomato spotted wilt virus (TSWV) which they transmit. The economic threshold is therefore almost zero, which enhances the problems of resistance management. The present work is part of a global project that attempts to evaluate the status of insecticide resistance in field populations of thrips obtained from several agricultural crops. We have studied, in either individual or pooled insects, some enzyme systems classically related to detoxification of insecticides: esterase and glutathione-S-transferase (GST). The activity of these enzymes from laboratory populations selected with various classes of insecticides has also been measured using several appropriate substrates. An increase in GST mean activity was found in two field-collected strains. Differences in frequency distributions of esterase and GST activities were found for both field-collected strains and for a laboratory strain selected with acrinathrin. These activities were compared with those of a wild-type reference strain.  相似文献