Seed production of Charybdis feriatus (Linnaeus)     

Fe D Parado-Estepa  Emilia T Quinitio  & Eduard Rodriguez 《Aquaculture Research》2007,38(14):1452-1458

Some aspects of the reproductive biology of Charybdis feriatus (Linnaeus) were investigated to identify suitable techniques for broodstock management and seed production. Likewise, factors such as ablation, water depth and light requirements affecting survival or reproductive performance were tested. Production of megalops in tanks and juveniles in net cages installed in earthen ponds was conducted. Wild‐caught berried females produced a significantly higher number of zoeae per gram body weight (BW) of the female (3300±600) than captive spawners (867±58). Ablated and unablated crabs spawned after a month and ovaries of both had oocytes in all developmental stages after spawning, indicating that ablation was not necessary. Broodstock survived higher when stocked in 1 m‐deep water and kept in dark conditions compared with shallow (0.5 m depth) water or ambient lighting. There were six zoea and one megalopa stage. Megalops were produced (survival of 2–22% in 1 tonne or 23–55% in 3 L tanks) when methods for the mud crab Scylla serrata (Forsskål) were used, but feeding with Artemia started only at the Z4 stage. Survival of megalops after 1 month was higher when stocked in net cages installed in an earthen pond (32–82%) than when reared continuously in land‐based tanks (5–11%).  相似文献   

Morphological and biochemical changes in the muscle of the marine shrimp Litopenaeus vannamei during the molt cycle     

Jose Renato de Oliveira Cesar  Spencer Malecha  Jinzeng Yang 《Aquaculture (Amsterdam, Netherlands)》2006,261(2):688-694

Morphological changes and biochemical composition of abdominal muscles over the molt cycle were investigated in juvenile Litopenaeus vannamei. Eight molt stages were characterized and clear uropod images are presented. Molt frequency was highly correlated with the age of the shrimp. Juvenile shrimps appeared to molt faster at one month of age (4.6 ± 0.5 days/cycle), slow to 11.8 ± 1.7 days/cycle at three months of age, and reach a long molt cycle at six months (17.2 ± 2.7 days/cycle). Myofiber cross-sectional images revealed specific morphological changes in abdominal muscle associated with each molt stage. Expanded fiber size was observed during intermolt stages. Water content and total soluble proteins were balanced throughout the molt cycle. Total DNA concentration increased in intermolt and premolt, while total RNA concentration remained stable except in late-premolt stages. SDS-PAGE analysis showed high levels of actin and myosin in postmolt, reaching a plateau in intermolt and declining in premolt. These results suggest the occurrence of muscle fiber rearrangement in both the premolt and postmolt stages. Abdominal muscle buildup occurs mostly during the intermolt stage.  相似文献   

Deposition of gold mining tailings in tropical soils: metal pollution and toxicity to earthworms     

Cesar  Ricardo  Arruda  Fernanda  Ramiro  Vanessa  Faria  Roberto  Barcelos  Daniel  Pontes  Fernanda  Passos  Fabiano  Kaiser  Karoline  dos Santos Teixeira  Aline Maria  Serrano  Aline  Abreu  Leticia  Siqueira  Danielle  Teixeira  Matheus  Vezzone  Mariana  Polivanov  Helena  Castilhos  Zuleica 《Journal of Soils and Sediments》2022,22(2):547-558

Journal of Soils and Sediments - This study consists of the evaluation of metals acute toxicity levels taking into consideration a hypothetic scenario of dam breaking and land deposition of two...  相似文献   

Milk Yield of Holstein Cows Induced into Lactation Twice Consecutively and Lactation Curve Models Fitted to Artiifcial Lactations     

Jesus Mellado  Edgar Sepulveda  Jose E Garcia  Alvaro Rodriguez  Maria A De Santiago  Francisco G Veliz  Miguel Mellado 《中国农业科学(英文版)》2014,(6):1349-1354

Nineteen multiparous barren Holstein cows were subjected to an induction of lactation protocol for 21 d administering estradiol cypionate （2 mg kg-1 of body weight （BW） d-1, on day 1 to 14）, progesterone （0.10 mg kg-1 of BW, on day 1 to 7）, lfumethasone （0.03 mg kg-1 of BW, on day 18 to 20） and recombinant bovine somatotropin （rbST;500 mg per cow, on day 1, 6, 16 and 21）. At the end of lactation and with a minimum of a 2-mon dry period, the same cows were again hormonally induced into lactation. Cows in both lactations were not artiifcially inseminated, they were milked 3 times daily and received rbST throughout lactation. Mean accumulated milk yield at 305 d in milk （DIM） did not differ between the ifrst and second induced lactations （（9 710 ＆#177;1 728） vs. （9 309＆#177;2 150） kg;mean＆#177;SD）. Total milk yield （（12 707＆#177;3 406） vs. （12 306＆#177;4 218） kg;mean＆#177;SD） and lactation length （（405＆#177;100） vs. （410＆#177;91） d;mean＆#177;SD） were not different between the ifrst and second induced lactations. In a second study, 15 empirical models including exponential, power law, yield-density, sigmoidal and miscellaneous models were compared for their suitability by modeling 12-mon （n=334）, 18-mon （n=164） and 29-mon （n=22） lactation cycles of Holsteins cows induced into lactation and treated with rbST throughout the lactation. Hoerl （Y=ab1/xxc）, Wood （Y=axb exp（cx）） and Dhanoa （Y=ax（bc）exp（cx）） models were equally suitable to describe 12-mon lactations. An exponential model with ifve parameters （Y=exp（a＋bx＋cd2＋e/x）） showed the best ift for milk yield for 18-mon lactations. The rational model （Y=a＋bx/1＋cx＋dx2） was found to produce the closest ift for 29-mon lactations. It was concluded that, with the protocol used in the present study, multiparous cows respond favorably to a second cycle of induced lactation, with milk yield similar to that experienced during the ifrst cycle. Thus, dairy producers might be able to lengthen the productive life of infertile high producing cows with a renewal of artiifcial lactation, which would imply an overall reduction in voluntary culling of cows. Also, various equations used to describe the lactation curves demonstrated the potential for iftting monthly milk records of Holstein cows with prolonged lactations and induced hormonally into lactation.  相似文献   

Microbiological Quality Assessment of Watershed Associated with Animal-Based Agriculture in Santa Catarina, Brazil     

Gilbert C. Sigua  Julio Cesar Pascale Palhares  Jalusa Deon Kich  Magda Regina Mulinari  Rosemari Martini Mattei  Jaqueline Bianca Klein  Susana Muller  Gustavo Plieske 《Water, air, and soil pollution》2010,210(1-4):307-316

Environmental problems many times could evolve when manure-containing pathogens are distributed into an open environment with no effort made to reduce the content of pathogens or limit their movement in the environment. Wind, surface flow, and subsurface flow can all carry enough pathogens to receiving waters to exceed water quality standards. This study was conducted to assess the microbiological quality of water associated with animal-based agriculture in the sub-basin of Pinhal River located in the rural area of Concordia, Santa Catarina, Brazil. Six sampling points representing different agricultural land uses (LU1—dairy cattle; LU2—without animals; LU3—dairy + pigs + poultry + crops; LU4—pigs + poultry + crops; LU5—dairy + pigs + poultry + crops + human; and LU6—dairy+pigs+crops) along the Pinhal River sub-basin (north to south) were sampled biweekly from August 2006 to December 2008. Concentrations of fecal coliforms and Escherichia coli varied significantly (p?≤?0.05) with land use (LU), but there was no interaction effect of LU, season, and time. Water samples from the catchment area of LU1 had the highest concentration of fecal coliforms (4,479?±?597 CFU ml^?1) when compared with other catchment areas. Catchment area associated with LU2 (no animal) had the lowest concentrations of fecal coliforms (39.2?±?5.2 CFU ml^?1). With the exception of LU2 (control site), all the maximum concentrations of E. coli exceeded the single maximum allowable concentration for E. coli (100 CFU ml^?1). When LU1 was compared with other catchment areas (LU3, 50%; LU4, 67%; LU5, 58%; and LU6, 44%), it had the lowest counts (39%) of Salmonella sp. Our results suggest that spatial pattern of bacterial water quality is evident, which can be linked to the different land uses and associated practices (present or absent of animal activities). Therefore, varying responses associated with the different land uses would be critical in identifying the importance of different sources of bacteria in the catchment area and the mechanisms transferring them.  相似文献   

Topographie des Collecteurs Lymphatiques Mammaires de la Chienne     

J. Ruberte    J. Y. Sautet    J. M. Gine    C. Lopez  A. Rodriguez 《Anatomia, histologia, embryologia》1990,19(4):347-358

The topography of the lymph drainage was examined by in vivo injections of india ink into the mammary parenchyma of 73 female dogs. Only one gland was injected at a time on each side. Only the cranial abdominal mammary gland had direct drainage to the axillary as well as to the superficial inguinal nodes. The principal routes of drainage differ for each gland. The glands on each side are completely independent as regards their lymph drainage. The cranial thoracic mammary glands on each side had their own collecting duct which led to the sternal lymph nodes. The results of this study suggest to develop a new model for the surgical extirpation of mammary tumors in the bitch.  相似文献   

Changes in Cd,Cu, Ni,Pb and Zn Fractionation and Liberation Due to Mussel Shell Amendment on a Mine Soil     

David Fernndez‐Calvio  Lorena Prez‐Armada  Laura Cutillas‐Barreiro  Remigio Paradelo‐Núez  Avelino Núez‐Delgado  María J. Fernndez‐Sanjurjo  Esperanza lvarez‐Rodriguez  Manuel Arias‐Estvez 《Land Degradation \u0026amp; Development》2016,27(4):1276-1285

Mining activities are related to relevant environmental pollution issues that should be controlled. We used sequential extractions to fractionate Cd, Cu, Ni, Pb and Zn retained on unamended or mussel shell‐amended mine soil samples, all of them treated with a mixture of the five heavy metals (total metal concentration of 1·57 mmol L⁻¹), after 1, 7 and 30 days of incubation. In addition, we used the stirred flow chamber technique to study the release of each of the five heavy metals from these different unamended and shell‐amended soil samples. The results indicate that the shell amendment caused a decrease in the most soluble fraction, while increasing the most recalcitrant (least mobile) fraction. With equivalent implications, the stirred flow chamber experiments showed that mussel shell amendment was associated to a decrease in heavy metal release and increased retention. The highest mussel shell dose and incubation time caused the most relevant changes in pH values and thus in metal retention, also indicating the importance of pH modifications in the mechanism of retention acting in the amended samples. In view of these results, the use of mussel shell amendment can be encouraged to increase heavy metal retention in acid mine soils, in order to minimise risks of environmental pollution. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Characterization for agronomic use of cytoplasmic male-sterility in sunflower (Helianthus annuus L.) introduced from H. resinosus Small     

M. M. Echeverria    M. T. Salaberry  R. H. Rodriguez 《Plant Breeding》2003,122(4):357-361

A backcrossing programme was carried out both to assess the stability of a cytoplasmic male‐sterility (CMS) source from Helianthus resinosus, designated RES1, and to incorporate it into inbred sunflower lines (HA89, RHA271, RHA801). All the progenies, grown in different environments, were completely male‐sterile. This suggests that the expression of this cytoplasm is stable. Female‐fertility of lines HA89, RHA271 and RHA801 carrying CMS RES1 were compared with those of the corresponding fertile inbred lines. There were no differences in the number of seeds per head. This indicates that female‐fertility is not affected by RES1 cytoplasm. Cytological studies showed that meiosis proceeds normally until the tetrad stage; consequently, the absence of pollen is caused by alterations that take place during postmeiotic stages. With the aim of identifying male‐fertility restorer genotypes, crosses were made between HA89 (CMS RES1) plants and different annual diploid and perennial hexaploid Helianthus species. All the diploid germplasm evaluated behaved as a CMS RES1 maintainer. However, the hexaploid species, H. resinosus, H. x laetiflorus, H. pauciflorus and H. tuberosus, restored pollen fertility in CMS RES1 plants.  相似文献   

Development of an appropriate breeding scheme for tolerance to Empoasca kraemeri in common bean     

Julia L. Kornegay  Cesar Cardona 《Euphytica》1990,47(3):223-231

Summary Significant advances in increasing tolerance to the leafhopper Empoasca kraemeri Ross & Moore in common bean have been obtained using a new breeding scheme where yield under leafhopper attack is the principal selection criterion in the evaluation of progenies. However, to further refine this breeding scheme, a study was conducted to determine whether selection for nonprotected yield would be more effective in early versus late generations. Two selection strategies were compared. In Strategy I, early generation selections in the F₂ and F₃ were compared to Strategy II where late generation selections were made in the F₄ and F₅, with the F₂ and F₃ generations advanced using single pod descent and bulk practices, respectively. Yield trials of the F₆ lines from both selection strategies were conducted under nonprotected and insecticide protected treatments. No significant differences were detected between the two selection strategies. However, Strategy II did produce advanced lines with greater nonprotected yields than did Strategy I, with the best F₆ line, in three out of four crosses, coming out of Strategy II. Late generation selection is recommended over early generation selection. Results of the new leafhopper breeding scheme, based on yield, are compared to the old breeding scheme where selections were made using visual selection practices in early generations.  相似文献   

Differential Adaptation of Complete and Substituted Triticale     

C. Royo    A. Rodriguez  I. Romagosa 《Plant Breeding》1993,111(2):113-119

Adaptation of seven complete and twelve substituted triticales to specific soil types has been studied, based on a series of twenty trials carried out in 1989 and 1990 across Spain. The nature of the GE interaction for grain yield was revealed by means of the additive main effects multiplicative interaction (AMMI) model and using the soil pH at the different sites as linear covariate. The percentage of the variability explained by the first principal component axis of the AMMI model was 72 and 65 % for the two years, suggesting a specific pattern of adaptation. Soil pH was the single most important environmental factor to explain the adaptation of complete and substituted types. Complete triticales outyielded substituted genotypes in the majority of sites. Triticale adaptation to acid and alkaline soils seems to be largely controlled by the single wheat/rye chromosome 2D(2R) substitution, for which both types differ. Complete triticales seem better adapted to the acid soils, whereas substituted types are, in general, more suited to alkaline soils.  相似文献