Survival of Post‐larval Litopenaeus vannamei Following Acclimation to Low Salinity Waters at Different Temperatures     

Patricio E. Paz  Luke A. Roy  D. Allen Davis  Herbert E. Quintero 《Journal of the World Aquaculture Society》2011,42(4):575-579

Temperature and salinity are two factors known to influence the growth potential and survival of the Pacific white shrimp, Litopenaeus vannamei, acclimated to low salinity waters. In west Alabama, farmers suspect low water temperatures at stocking, in conjunction with low salinity and suboptimal ionic profiles, might be responsible for reduced survival and production at harvest. To determine the influence of temperature and salinity on post‐larval (PL) L. vannamei, a series of bioassays were conducted at the E.W. Shell Fisheries Research Station in Auburn, Alabama and Claude Peteet Mariculture Center in Gulf Shores, Alabama. PL L. vannamei of ages 11, 13, and 20 (PL₁₁, PL₁₃, and PL₂₀) were acclimated down to salinities of 12, 4, 2, 1, 0.5, and 0.2 ppt at different temperatures ranging from 17.6 to 24.0 C. During the acclimation bioassays survivals were assessed at 24 and 48 h. PL survival of the three age groups examined were significantly reduced at salinities of 1, 0.5, and 0.2 ppt. These results correspond well to those reported at higher temperatures confirming that across the tested temperature range salinity endpoint was the driving factor in determining survival and that suboptimal temperatures had a minimal influence on survival.  相似文献   

Early stages of Margaritifera margaritifera glochidiosis in Atlantic salmon: Morphopathological characterization     

Pedro A. Castrillo  Catuxa Varela-Dopico  Paz Ondina  María Isabel Quiroga  Roberto Bermúdez 《Journal of fish diseases》2020,43(1):69-80

Freshwater mussels of the order Unionida encyst into the fish mucosa to metamorphose and complete their life cycle, causing a parasitic disease known as glochidiosis. This parasitic stage represents a bottleneck for the survival of naiads, particularly for critically endangered species as Margaritifera margaritifera; however, little is known about the events occurring during this critical stage. Therefore, this study aimed to histologically characterize the development of M. margaritifera glochidiosis in Atlantic salmon to get insight into the pathogenesis of this interaction. Fish exposed to glochidia were sampled during the first 44 days post-exposure, and organs were observed by stereomicroscopy and light microscopy. Glochidia attached to the gills by pinching the lamellar epithelium, whereupon an acute proliferative branchitis engulfed most of the larvae. However, during the first 14 days, a severe detachment of unviable glochidia occurred, associated with the presence of pleomorphic inflammatory infiltrate and epithelial degeneration. In the cases where larvae remained attached, a chronification of the lesions with none to scarce inflammation was observed. These results provide key information to better understand the complex host–parasite interaction during the early stages of glochidiosis and provide valuable information to optimize artificial rearing of naiads in conservation of threatened freshwater mussel populations.  相似文献   

Loss of genetic variability in the captive stocks of tambaqui,Colossoma macropomum (Cuvier, 1818), at breeding centres in Brazil,and their divergence from wild populations          下载免费PDF全文

Jonas da Paz Aguiar  Paola Fabiana Fazzi Gomes  Igor Guerreiro Hamoy  Sidney Emanuel Batista dos Santos  Horacio Schneider  Iracilda Sampaio 《Aquaculture Research》2018,49(5):1914-1925

The loss of variability in farmed populations and the risks of interactions with wild populations support the need for the genetic monitoring of species farmed throughout the world. In Brazil, the tambaqui is the most widely farmed native fish species. Despite this, there are no data on the pedigree of the farmed stocks, and the potential for interactions with wild populations in the Amazon basin has raised concerns with regard to the genetic variability of these stocks. The present study analysed sequences of the mitochondrial Control Region and 12 microsatellites to characterize the genetic variability of seven historically important commercial tambaqui breeding centres located in four different regions of Brazil, and compared these sequences with those obtained from individuals collected from a wild population. High levels of genetic diversity were found in the wild population, whereas genetic diversity was reduced in both markers in most captive populations, except for the broodstock located near the Amazon River. High F_ST and D_EST indices were recorded between the wild population and most of the captive stocks analysed. The drastic reduction in genetic diversity found in most captive stocks and the difference between these stocks and the wild population may have been the result of the small size of the founding populations and the absence of breeding management. The renewal of the broodstocks and the application of breeding management techniques are recommended. In the Amazon region, in addition, the use of broodstocks that are genetically very different from local wild populations should be avoided.  相似文献   

Molecular epidemiology of selected infectious diseases caused by bacteria in juveniles and post‐larvae of the white shrimp Penaeus vannamei from the north‐western coast of Mexico          下载免费PDF全文

T Enríquez‐Espinoza  F Mendoza‐Cano  T Encinas‐García  A Sánchez‐Paz 《Journal of fish diseases》2016,39(11):1393-1397

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Reissner's Fibre Proteins and p73 Variations in the Cerebrospinal Fluid and Subcommissural Organ of Hydrocephalic Rat   总被引：1，自引：0，他引：1  

E. M. Carmona-Calero  I. González-Marrero  J. M. González-Toledo  A. Castañeyra-Ruiz  H. De Paz  -Carmona  L. Castañeyra-Ruiz  P. Fernández-Rodriguez  M. L. Ruiz-Mayor    A. Castañeyra-Perdomo 《Anatomia, histologia, embryologia》2009,38(4):282-285

Reissner's fibre (RF) is formed by the polymerization of the glycoprotein secreted by the subcommissural organ (SCO). The SCO also secretes soluble glycoprotein into the cerebrospinal fluid (CSF); variations in RF and SCO have been reported in hydrocephalus. On the other hand, hydrocephalus and other brain alterations have been described in p73 mutant mice. The p73 belongs to the tumour suppressor p53 protein family and has two isoforms: the TAp73 with apoptotic activity and ΔNp73 with anti-apoptotic function. Moreover, the TAp73 isoform is glycosylated and secreted into the CSF. In the present work, we analysed the variations in RF and p73 proteins in the CSF and SCO of spontaneously hydrocephalic rats. Brains from control rats and spontaneously hydrocephalic rats of 12 months of age were used. The SCO sections were immunohistochemically processed with anti-TAp73 and anti-Reissner fibre (AFRU). The spontaneous hydrocephalus presents a decrease in the AFRU immunoreactive material in the SCO and an absence of RF. The anti-TAp73 was also present, slightly decreased, in the hydrocephalic SCO. AFRU and p73 bands were also detected in the CSF by western blot and six AFRU and p73 protein bands of a similar molecular weight were found in the CSF of the control rats. The number of AFRU and p73 bands was lower in the hydrocephalic rats than in the control rats. In conclusion, hydrocephalus produces a decrease in the secretions of the SCO and an absence of RF and a decrease in p73 and RF proteins in the CSF.  相似文献   

An empirical equation to calculate soil solution electrical conductivity at 25°C from major ion concentrations     

F. Visconti  J. M. De Paz  J. L. Rubio 《European Journal of Soil Science》2010,61(6):980-993

The electrical conductivity at 25°C (EC₂₅) of soil solutions or irrigation waters is the standard property for assessing salinity. Many models for soil salinity prediction calculate the major ion composition of the soil solution. The electrical conductivity of a solution can be determined from its composition through several different empirical equations. An assessment of these equations is necessary to incorporate the most accurate and precise equations in such models. Twelve different equations for the EC₂₅ calculation were calibrated by means of regression analyses with data from 133 saturation extracts and another 135 1:5 soil‐to‐water extracts from a salt‐affected agricultural irrigated area. The equations with better calibration parameters were tested with another data set of 153 soil solutions covering a wide range of salt concentrations and compositions. The testing was conducted using the standardized difference t‐test, which is a rigorous validation test used in this study for the first time. The equations based on the ionic conductivity decrement given by Kohlrausch's law presented the poorest calibration parameters. The equations founded on the hypothesis that EC₂₅ is proportional to analytical concentrations had worse calibration and validation parameters than their counterparts based on free‐ion concentrations and ionic activities. The equations founded on simpler mathematical relationships generally gave improved validation parameters. The three equations based on the specific electrical conductivity definition presented a mean standardized difference between observations and predictions indistinguishable from zero at the 95% confidence level. The inclusion of the charged ion‐pair concentrations in the equation based on free‐ion concentrations improved its predictions, particularly at large electrical conductivities. This equation can be reliably used in conjunction with chemical speciation software to assess EC₂₅ from the ion composition of soil solutions.  相似文献   

Caudal epidural anesthesia in mares after bicarbonate addition to a lidocaine–epinephrine combination     

Patricia C. Duarte  Cahuê F.R. Paz  Alvaro P.L. Oliveira  Thairê P. Maróstica  Leticia O. Cota  Rafael R. Faleiros 《Veterinary anaesthesia and analgesia》2017,44(4):943-950

Objective

To investigate the nociceptive and clinical effects of buffering a lidocaine–epinephrine solution with sodium bicarbonate in caudal epidural block in mares.

Study design

Prospective randomized controlled trial.

Animals

Six mixed-breed mares weighing 350–440 kg.

Methods

Each animal was administered two caudal epidural injections, 72 hours apart, using different solutions prepared immediately before injection. The control solution was 7 mL 2% lidocaine hydrochloride with epinephrine hemitartrate (1:200,000) added to 3 mL sterile water for injection (pH 2.9). The alkalinized solution was 7 mL of lidocaine–epinephrine solution added to 2.3 mL sterile water for injection and 0.7 mL 8.4% sodium bicarbonate (pH 7.4). Nociception was evaluated by response to skin pinching at 31 sites in the sacral region and around the perimeter of the anogenital area (distances of 10, 15 and 20 cm) before, and 5, 10 and 15 minutes after epidural injection, then every 15 minutes until the return of nociception in all evaluated sites. The onset and duration times, and intensity of ataxia (grades 0 to 3) were recorded. The paired t test was used to compare the onset and duration of anesthesia and ataxia (p < 0.05).

Results

Alkalization of the solution resulted in significant decreases in the average time of onset of loss of nociception in the sacral region (40%) and around the perimeter of the anogenital area extending up to 5 cm (36%) and from 5 to 10 cm (32%) from the anus and vulva. Alkalization also decreased the average duration of ataxia (33%), without affecting the duration and extent of anesthesia or the degree of ataxia.

Conclusions and clinical relevance

Alkalization of lidocaine–epinephrine solution is advantageous in shortening the duration of ataxia and hastening the onset of anesthesia in areas adjacent to the anogenital area, without reducing the duration of epidural anesthesia, in mares.  相似文献   

Survey of Victorian small ruminant herds for mycoplasmas associated with contagious agalactia and molecular characterisation of Mycoplasma mycoides subspecies capri isolates from one herd          下载免费PDF全文

OM Olaogun  A Kanci  SR Barber  KA Tivendale  PF Markham  MS Marenda  GF Browning 《Australian veterinary journal》2017,95(10):392-400

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The Acidic Probe LysoSensor™ is not Useful for Acrosome Evaluation of Cryopreserved Ram Spermatozoa     

D Castro‐González  M Álvarez  J Muro  MC Esteso  P De Paz  L Anel  F Martínez‐Pastor 《Reproduction in domestic animals》2010,45(2):363-367

To try new acrosomal probes for assessing ram spermatozoa, we compared the LysoSensor^? probe, which labels acidic organelles, with the frequently used peanut agglutinin acrosomal probe (PNA‐PE; phycoerythrin as fluorescent moiety). The previous microscopic observations showed a lack of relationship of LysoSensor^? with acrosomal status. Semen was obtained from five rams and frozen in four pools. Each pool was analysed carrying out a triple staining propidium ioide/PNA‐PE/LysoSensor^? Green DND‐189 to test acrosome labelling, and a double staining SYBR‐14/PI, to assess sperm viability. Stained samples were analysed by flow cytometry. All measurements were replicated. Data were processed using agreement and repeatability tests. LysoSensor^? labelling did not agree with PNA (mean of differences: 30.8%; coefficient of agreement: 22.6%), confirming microscopic observations. Nevertheless, when LysoSensor^? was compared with SYBR‐14/PI, the agreement was high (mean of differences: ?0.05%; coefficient of agreement: 5.07%). Repeatability of both methods was high and similar. LysoSensor^? did not seem to specifically stain the acrosome, but it may accumulate in the cytoplasm and label viable spermatozoa. Therefore, LysoSensor^? might not be used as an acrosomal probe in ram spermatozoa, but it could be used in other kind of studies, taking advantage of its pH sensitivity.  相似文献   

Greenhouse gas emissions between 1993 and 2002 from land-use change and forestry in Mexico     

Ben de Jong  Carlos Anaya  Omar Masera  Marcela Olguín  Fernando Paz  Jorge Etchevers  René D. Martínez  Gabriela Guerrero  Claudio Balbontín 《Forest Ecology and Management》2010

In this paper we present the Mexican inventory of greenhouse gas (GHG) emissions from the land-use sector. It involved integration of forest inventory, land-use and soil data in a GIS to estimate the net flux of GHG between 1993 and 2002.  相似文献