First results of embryonic development,spawning and larval rearing of the Mediterranean spider crab Maja squinado (Herbst ) under laboratory conditions,a candidate species for a restocking program     

Juana Durán  Elena Pastor  Amalia Grau  José María Valencia 《Aquaculture Research》2012,43(12):1777-1786

The Mediterranean spider crab, Maja squinado, is depleted due to overfishing. The crab has virtually disappeared from areas where it was abundant, such as the Balearic Islands and the Catalan coast. Maja squinado, is economically and ecologically very valuable, and it is essential to obtain information on its biology and rearing conditions to attempt to repopulate the damaged stocks of the species in the Mediterranean basin. Herein, we describe the first successful rearing of M. squinado under laboratory conditions. Our results show that M. squinado is an excellent candidate for restocking using cultured juveniles. Two consecutive broods with a 1–4 day interbrood period were observed in the laboratory in wild‐caught females, the maximum observed duration of embryonic development of the egg mass being 32 days at 18.4 ± 0.9°C, and went through four different stages. The complete larval and first juvenile development was studied in laboratory cultures fed enriched Artemia metanauplius. At 19.6 ± 0.6°C, development from hatching to first crab moult took 17 days, and it comprised two zoeae stages and one megalopa stage. The survival rate at the different stages was monitored, and 7.13 ± 2.3% was achieved at the first crab instar.  相似文献   

Intensive rearing of juvenile crayfish (Pacifastacus leniusculus,Astacidae) during the first 6 months: effects of size grading     

Rocío González  Jesús Domingo Celada  José Manuel Carral  Vanesa García  María Sáez‐Royuela  Álvaro González 《Aquaculture Research》2011,42(9):1385-1392

Recent advances in crayfish feeding have enabled the development of size grading studies from the start of first‐feeding. A 180‐day experiment aimed at intensive rearing of Pacifastacus leniusculus was carried out under controlled conditions, evaluating the effects of size grading at two different periods from the onset of exogenous feeding. Stage 2 juveniles were stocked in fibreglass tanks at a density of 100 m², and fed a dry diet for salmonids combined with restricted amounts of Artemia cysts. Five groups were tested: no grading, grading at 60 days (large and small size) and grading at 100 days (large and small size). After 6 months, no significant differences were found in the survival among groups (mean: 73.06%). The highest final growth (pooled results from upper and lower classes: 17.39 mm carapace length, 1.43 g weight) was achieved by the crayfish sorted at 60 days, showing significant differences from the ungraded group. Smaller crayfish graded at 60 days grew significantly faster than smaller crayfish graded at 100 days. The food conversion ratio was lower in the graded groups (mean: 2.64), showing significant differences from the ungraded group (3.23). This study shows that size grading allows a better performance and an improved feeding efficiency.  相似文献   

Acute tolerance and histopathological effects of ammonia on juvenile maroon clownfish Premnas biaculeatus (Block 1790)     

Ricardo Vieira Rodrigues  Luis Alberto Romano  Michael Hans Schwarz  Brendan Delbos  Luís André Sampaio 《Aquaculture Research》2014,45(7):1133-1139

This study evaluated the median lethal concentration values (LC₅₀) and the histopathological effects of un‐ionized ammonia (NH₃^‐‐N) on juvenile maroon clownfish Premnas biaculeatus. After 96 h of exposure to different concentrations of ammonia, juveniles were sampled for histopathological evaluation. The 24 and 96 h LC50 values of NH₃^?‐N determined were 1.68 and 0.89 mg L^?1 respectively. Maroon clownfish exposed to different ammonia concentrations displayed histopathological alterations in the gills, kidney, liver and brain. Gill tissue damage included lamellar hyperplasia, lamellar shorting and hyperplasia and hypertrophy of mucous cells. The kidney showed hyperanaemia, enlarged sinusoids within an apparently decreased amount of haematopoietic tissue, oedema on tubular cells and tubular necrosis, and an enlarged Bowman's capsule. The liver presented dilatation of hepatic sinusoids, fatty deposition in hepatocytes and Mallory bodies. Examination of the brain revealed a proliferation of glial cells, and the Virchow‐Robin space indicated a severe perivascular oedema and signs of neuronal suffering with satellitosis. The results of this study indicate that juvenile maroon clownfish are relatively sensitive to ammonia and particular attention must be given to this toxic compound in culture systems.  相似文献   

Physiological responses of Quercus oleoides (Schltdl & Cham) to soils contaminated by diesel     

Yudith Viridiana Castro-Mancilla  Sergio Castro-Nava  José Guadalupe Martínez-Avalos 《Plant Production Science》2013,16(4):519-529

ABSTRACT

Oil pollution is a worldwide threat to the environment that affects the development of plants. The effect of soil contaminated by diesel on the physiological responses of seedlings of Quercus oleoides was investigated in two independent experiments. We proposed that physiological performance will decrease when seedlings are exposed to higher concentration of contamination. At the first experiment, levels of pollution with diesel were of 0%, 5%, 10% and 15%, and 0%, 2% and 3.5% in the second one. In the first experiment, photosynthetic rate, stomatal conductance, transpiration and total chlorophyll of Q. oleoides were higher in the control seedling, and lower in treatments of pollution with 5%, 10% and 15% of diesel during 3 days of treatment. Only, seedlings in soil polluted with 5% of diesel survived up to 16 days; they showed a photosynthetic rate of 5 μmol m^?2 s^?1, which was lower than control seedlings (9 μmol m^?2 s^?1). This pattern was observed in stomatal conductance, transpiration and relative water content. Surprisingly, in the second experiment, seedlings showed a higher photosynthetic rate and growth at 2% of diesel-contaminated soil than control seedlings, a phenomenon known as hormesis. In both experiments, soil respiration was proportional to soils contaminated. We concluded that Q. oleoides is highly vulnerable in soils contaminated with above 5% of diesel, but it maintains its physiological activities in soils contaminated below 2%, suggesting that seedlings can grow under low concentration of diesel contaminant, and may be used in phytoremediation of soils with low concentrations of diesel contamination.  相似文献   

Isolation of viral haemorrhagic septicaemia virus from mummichog, stickleback, striped bass and brown trout in eastern Canada     

Gagné N  Mackinnon AM  Boston L  Souter B  Cook-Versloot M  Griffiths S  Olivier G 《Journal of fish diseases》2007,30(4):213-223

Viral haemorrhagic septicaemia virus (VHSV) was isolated from mortalities occurring in populations of mummichog, Fundulus heteroclitus, stickleback, Gasterosteus aculeatus aculeatus, brown trout, Salmo trutta, and striped bass, Morone saxatilis, in New Brunswick and Nova Scotia, Canada. The isolated viral strains produced a cytopathic effect on the epithelioma papillosum cyprini cell line. Serum neutralization indicated the virus was VHSV and sequencing identified the rhabdovirus isolates as the North American strain of VHSV. Phylogenetic analysis indicated that the isolates are closely related and form a distinguishable subgroup of North American type VHSV. To our knowledge, this is the first report of VHSV in mummichog and striped bass.  相似文献   

Regression modeling nitrogen fertilization requirement for maize crop by combining spectral reflectance and agronomic efficiency     

Cláudio Kapp-Junior  Alaine Margarete Guimarães  André Carlos Auler 《Journal of plant nutrition》2020,43(14):2152-2163

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Aboveground biomass,transpiration and water use efficiency in eucalypt plantation fertilized with KCl,NaCl and phonolite rock powder     

de Toledo  Fábio Henrique S. F.  de Moraes Gonçalves  José Leonardo  Mariño  Yesid Alejandro  de Vicente Ferraz  Alexandre  de Oliveira Ferreira  Eric Victor  Moreira  Gabriela Gonçalves  Hakamada  Rodrigo  de Arthur Júnior  José Carlos 《New Forests》2020,51(3):469-488

Potassium has important physiological functions in eucalypt plantations, increasing their productivity when applied to soil via mineral fertilizers. There is interest in identifying alternative sources to KCl owing to its high cost and limited reserves. The aim of the study was to test the effect of replacing KCl with NaCl and phonolite rock powder. Two comparisons were made: (1) application of 283 kg ha^?1 of KCl compared with that of 2125 kg ha^?1 of phonolite rock powder (equivalent to 170 kg ha^?1 of K₂O in both treatments); (2) application of 139 kg ha^?1 of NaCl compared with that of 183 kg ha^?1 of KCl (equivalent to 2.33 kmol Na and K, respectively). Radial growth, soil water content, leaf water potential (Ψ), accumulated transpiration, stem volume and biomass increment, as well as water use efficiency (WUE) were evaluated. In the first comparison, both fertilizations presented equal values for all characteristics evaluated. In the second, the accumulated transpiration in trees fertilized with KCl was 17% higher than that in plants fertilized with NaCl. In contrast, the WUE was 20% higher in the trees fertilized with NaCl than in those fertilized with KCl, reflecting the lower water consumption for the same increment in stem volume and biomass. We conclude that phonolite rock powder and NaCl are possible substitutes for conventional K fertilization performed with KCl.

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Evaluation of the effect of commercially available plant and animal protein sources in diets for Atlantic salmon (Salmo salar L.): digestive and metabolic investigations     

Mali Hartviksen  Anne Marie Bakke  José G. Vecino  Einar Ringø  Åshild Krogdahl 《Fish physiology and biochemistry》2014,40(5):1621-1637

The present study investigated the effect of various alternative diet ingredients partially replacing fishmeal (FM) on digestive and metabolic parameters in Atlantic salmon (Salmo salar L.) post-smolts (initial body mass 305 ± 69 g) following 12 weeks of feeding. Experimental diets containing 20 % extracted sunflower (ESF), pea protein concentrate (PPC), soy protein concentrate (SPC), feather meal (FeM) and poultry by-product (PBY) were compared to a reference diet containing FM as the main protein source. For the different intestinal compartments trypsin, lipase, bile salts, dry matter and chyme-associated leucine aminopeptidase (LAP) were measured from the content and LAP was measured in the tissue. Selected metabolites were measured in plasma samples. In general, use of plant proteins resulted in low C-LAP activity, low plasma cholesterol and high plasma magnesium. The plasma levels of cholesterol and Mg reflecting were most likely reflections of the composition of the diet, while the LAP activity in chyme may indicate lower epithelial cell turnover. Other responses varied depending on the plant protein source. Results from the animal protein substitution also varied both between diets and compartments; however, both materials increased lipase activity in DI. FeM resulted in a significant increase in both total and specific LAP activities suggesting an attempt to increase the digestive capacity in response to low digestibility of the diet while PBY showed very little difference from the FM-fed control fish. The present trial indicates that 20 % PPC, SPC and PBY can partially replace FM in diets for Atlantic salmon. The qualities of ESF and FeM used in this trial show little promise as FM replacement at 20 % inclusion level.  相似文献   

Natural Stable Isotopes for Determination of Gastrointestinal Transit Time in Fish          下载免费PDF全文

Lidiane Cristina Gonçalves de Sandre  Hellen Buzollo  Thiago Matias Torres do Nascimento  Lígia Maria Neira  Eduardo Gianini Abimorad  Rosangela Kiyoko Jomori  Carlos Ducatti  Maria Célia Portella  Dalton José Carneiro 《Journal of the World Aquaculture Society》2016,47(1):113-122

This study evaluated the application of stable isotopes of carbon as an alternative and more accurate method to determine gastrointestinal transit time (GTT) in fish by comparing it to the inert marker method. The stable isotope method detects alterations of the normal carbon flow in a biological system by analyzing naturally occurring isotopes of carbon, contrary to studies based on conventional techniques that apply external markers to the diet to determine GTT through visual observation of the color change in feces. Therefore, 320 pacu, Piaractus mesopotamicus juveniles were reared in 32 tanks under two different temperatures (25 and 29 C). The pacu juveniles received two different diets, one based on ingredients derived from C₃ photosynthetic cycle plants and the other based on C₄ plant ingredients, both containing titanium oxide (TiO₂) as a marker. After 40 d, the isotopic signature of the diets was changed, and the marker was replaced by chromic oxide (Cr₂O₃). In the isotopic technique, the feces were analyzed to determine the exchange in the isotopic ratio of carbon δ¹³C. Both methods found that GTT was faster (nearly 6 h) in fish at 29 C when using the C₄/C₃ feeding strategy and slower in fish at 25 C using the C₃/C₄ strategy (15 h by inert marker and 18 h by the isotopic method). In conclusion, GTT determination in pacu juveniles using the stable isotope technique exhibits the same accuracy obtained with the inert marker method at temperatures suitable (nearly 29 C) for the metabolism of these animals.  相似文献   

Does reverse growth dominance develop in old plantations of Eucalyptus saligna?     

Bui The Doi  Dan Binkley  José Luiz Stape 《Forest Ecology and Management》2010,259(9):1815-1818

Patterns of stand growth and dominance among individual trees change through stand development. We tested a prediction that large, old plantations of Eucalyptus saligna (Sm.) in Hawaii and Brazil would show a pattern of “reverse” growth dominance, with the largest trees contributing more to stand biomass than to current stand increment. This pattern might develop if the largest trees accounted for a large portion of the total resource use of the stand, but were less efficient at utilizing resources to produce stemwood. The 70-year-old plantation in Hawaii had a stem mass of 610 Mg/ha, compared with 325 Mg/ha in the 66-year-old Brazil plantation. Cumulative frequency plots for both sites showed that dominant trees comprised a very large proportion of total stand mass; the largest 20% of the trees accounted for 50% and 30% of the total stand mass in Hawaii and Brazil, respectively. Contrary to expectations, the largest trees continued to produce a disproportionately large amount of total stand growth, with the largest 20% of trees accounting for 60% (Hawaii) and 40% (Brazil) of stand growth. The frequency distributions resulted in positive growth dominance coefficients (similar to Gini coefficients) of 0.14 for Hawaii and 0.09 for Brazil, rather than negative values that would indicate that reverse growth dominance. The failure of these monoculture Eucalyptus stands to develop reverse growth dominance contrasts starkly with a variety of studies with pine species, which tend to show neutral-to-reverse growth dominance. Indeed, continued dominance of large trees suggests the trees might respond well to silvicultural treatments such as thinning or fertilization. Future work that contrasts patterns of growth dominance among species will be important as a foundation for developing generalizations about trends in growth dominance with stand development.  相似文献