Effect of combined stress (salinity + hypoxia) and auxin rooting hormone addition on morphology and growth traits in six Salix spp. clones

New Forests - Willows plantations development could be an alternative for hydro-halomorphic soils but it is limited by combined stress salinity?+?hypoxia (main stressor under...     

Phenotypic differences may limit the potential for habitat restoration involving species translocation: a case study of shape ecophenotypes in different populations of Modiolus modiolus (Mollusca: Bivalvia)

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Biochemical,Physical, Chemical,and Microbiological Assessment of Blue Shrimp (Litopenaeus stylirostris) Stored in Ice

Postmortem changes in blue shrimp (Litopenaeus stylirostris) muscle were studied on the basis of biochemical, chemical, physical, and microbiological changes during an 18 day storage period at 0°C. Adenosine 5′-triphosphate (ATP) content, breakdown products, K-value, pH, trimethylamine nitrogen (TMA-N), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), color, and texture (shear force) changes were examined. Also, total mesophilic and psychrophilic bacterial counts were measured. K-value increased linearly (r² = 0.98) from an initial value of 1.37 ± 0.59 to 59.42 ± 6.05% at Day 18. Spoilage indicators TVB-N and TMA-N increased from 29.56 ± 1.33 and 0.69 ± 0.25 to 39.04 and 2.04 ± 0.59 mg of N/100 g at Day 18, respectively; meanwhile, the total viable counts of mesophilic and psychrophilic bacteria increased from 3.48 ± 0.44 and 2.61 ± 0.29 log CFU/g to 6.27 ± 0.21 and 7.14 ± 0.39 log CFU/g, respectively, which indicated spoilage at the end of the storage period. The pH, texture, WHC, and color were affected (p < 0.05) during the storage period. Overall, results indicate that blue shrimp muscle quality was maintained for 12 days of storage in ice.     

Histological alterations in gills of shrimp Litopenaeus vannamei in low‐salinity waters under different stocking densities: Potential relationship with nitrogen compounds

Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp /m²) were examined weekly over a culture cycle in tanks with low‐salinity water (1.9 g/L) and zero water exchange. Results showed survival rates of 87.7 and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, electrical conductivity and chlorophyll a were not significantly (p > .05) different between modules. In contrast, the concentrations of nitrogen compounds were significantly (p < .05) different between modules, except nitrite‐N (M2 were 2.31 ± 1.38 mg/L N‐TAN, 0.18 ± 0.49 mg/L N‐NO₂^? and 6.83 ± 6.52 mg/L N‐NO₃^?; in M1: 0.97 ± 0.73 mg/L N‐TAN, 0.05 ± 0.21 mg/L N‐NO₂^? and 0.63 ± 0.70 mg/L N‐NO₃^?). When waters of both modules reached higher levels of ammonia and nitrite, histological alterations were observed in gills. The histological alterations index (HAI) was higher in M2 (5‐112) than in M1 (2‐22).     

Morphological development and allometric growth of yellowtail kingfish Seriola lalandi V. larvae under culture conditions

Morphological development and allometric growth patterns of Seriola lalandi larvae were assessed to characterize normal growth patterns under culture conditions. Early ontogenetic stages of yellowtail kingfish exhibited an exponential growth in terms of standard length as a function of age. Five development stages were characterized from hatching to the juvenile stage: larval stage I (0–2 days post hatch, dph) with endogenous feeding, characterized by a small yolk sac, unpigmented eyes, primordial finfold surrounding the body and a closed mouth; larval stage II (2–15 dph) characterized by mouth opening, complete pigmentation of eyes and the beginning of the exogenous feeding; subsequently, in the larval stage III (15–25 dph) the posterior tip of notochord of the larvae bended upward and the first rays appeared in fins, concomitant with a change in swimming behaviour; thereafter, larval stage IV (post‐flexion stage; 25–30 dph) began when larvae resembled in morphology to a juvenile organism; however, caudal and dorsal fins were not completely development. Lastly, the juvenile stage was reached 30 dph characterized by a morphology and fin structures similar to those of the adults. Growth and development of structures and organs associated with vital functions such as feeding, sensorial and breathing systems seemed to be more critical previous to 23 dph, which was reflected with a positive allometric growth of head and eyes during this period. The results from this study can be used as a tool‐guide to assess normal development in larval research with S. lalandi to improve existing rearing protocols in hatchery production.     

Limnology of Macrobrachium amazonicum grow‐out ponds subject to high inflow of nutrient‐rich water and different stocking and harvest management

We evaluated the water characteristics and particle sedimentation in Macrobrachium amazonicum (Heller 1862) grow‐out ponds supplied with a high inflow of nutrient‐rich water. Prawns were subject to different stocking and harvesting strategies: upper‐graded juveniles, lower‐graded juveniles, non‐graded juveniles+selective harvesting and traditional farming (non‐grading juveniles and total harvest only). Dissolved oxygen, afternoon N‐ammonia and N‐nitrate and soluble orthophosphate were lower in the ponds in comparison with inflow water through the rearing cycle. Ponds stocked with the upper population fraction of graded prawns showed higher turbidity, total suspended solids and total Kjeldahl nitrogen than the remaining treatments. An increase in the chemical oxygen demand:biochemical oxygen demand ratio from inlet (4.9) to pond (7.1–8.0) waters indicated a non‐readily biodegradable fraction enhancement in ponds. The sedimentation mean rate ranged from 0.08 to 0.16 mm day^?1 and sediment contained >80% of organic matter. The major factors affecting pond ecosystem dynamic were the organic load (due to primary production and feed addition) and bioturbation caused by stocking larger animals. Data suggest that M. amazonicum grow‐out in ponds subjected to a high inflow of nutrient‐rich water produce changes in the water properties, huge accumulation of organic sediment at the pond bottom and non‐readily biodegradable material in the water column. However, the water quality remains suitable for aquaculture purposes. Therefore, nutrient‐rich waters, when available, may represent a source of unpaid nutrients, which may be incorporated into economically valued biomass if managed properly.     

Effect of Density at Harvest on the Growth Performance and Profitability of Hatchery‐reared Spotted Rose Snapper,Lutjanus guttatus,Cultured in Floating Net Cages

This study evaluated the effect of the density at harvest on the performance and profitability of hatchery‐reared spotted rose snapper cultured in cages. The fish were stocked at harvest densities of 15, 20, and 22 kg/m³ in cages of 222 and 286 m³. More than 39,000 snapper fingerlings with an initial weight of 14 g were stocked. The fish were fed an extruded diet and cultured over a 360 d period. The thermal growth coefficient ranged from 0.04 to 0.05 and survival was 95% for all treatments, with the highest final weight (436.8 g) observed for fish reared at a density of 20 kg/m³. The allometric value b indicated that hatchery‐raised, cage‐cultured snapper were heavier than their wild counterparts. The major costs were feed (ranging from 44.7–45.9%), labor (22.4–32.6%), and seed costs (20.2–26.1%). The total production cost ranged from US$ 6.5 to US$ 7.5/kg. The baseline scenario was not economically feasible. However, a 10% increase in the sales price resulted in increases in the internal rate of return (183%) and net present value (US$ 97,628.9). These results suggest that L. guttatus has the potential for commercial production in cages.     

Ripening-related defense proteins in Annona fruit

In order to obtain a better understanding of the active defense strategy of cherimoya (Annona cherimola Mill.) fruit, hydrolytic and antifungal activity, as well as expression of proteins functionally and immunogenically related to the pathogenesis-related proteins chitinase (PR-Q) and 1,3-β-glucanase (PR-2), were estimated in fruit at different ripening stages. Increase in expression of the 27 kDa constitutive chitinase and the induction of two new proteins, a 26 kDa chitinase and a 51 kDa 1,3-β-glucanase were associated with enhanced in vitro hydrolytic and antifungal activity of the acidic protein extract in ripe fruit. Ripening modified the expression of constitutive basic isoenzymes, with a sharp decrease in both relative accumulation and hydrolytic activity. Likewise, a new basic 33 kDa chitinase was induced in the over-ripe fruit, concomitant with accumulation of a basic constitutive 76 kDa 1,3-β-glucanase. At this stage, the basic protein extract modified in vitro growth inhibition of Botrytis cinerea. Short-term high CO₂ treatment delayed fruit ripening and maintained a similar distribution of activity and isoenzymatic pattern in both protein fractions to that in unripe fruit. These results indicate that the changes in the pattern of defense proteins and hydrolytic activity in cherimoyas appear to be associated with ripening. Moreover, unlike the constitutively expressed isoenzymes, only the transitorily induced chitinases and 1,3-β-glucanases were associated with an active defense-related response.     

Chemical composition of the Lippia origanoides essential oils and their antigenotoxicity against bleomycin-induced DNA damage

The present work evaluated the chemical composition of the essential oils (EO) obtained from Lippia origanoides and their DNA protective effect against bleomycin-induced genotoxicity. L. origanoides EO chemical composition was determined by gas chromatography–mass spectrometry (GC–MS). The major compounds of the L. origanoides EOs were thymol (34–58%) and carvacrol (26%). The antigenotoxic effects of the EOs, major compounds and standard compound (epigallocatechin gallate) were assayed in co-incubation procedures using the SOS chromotest in Escherichia coli. Both EOs and their major compounds protected bacterial cells against bleomycin-induced genotoxicity indicating that these two compounds were principally responsible for the antigenotoxicity detected in the oils. Thymol and carvacrol antigenotoxicity was lower than those observed with epigallocatechin gallate. The results were discussed in relation to the chemopreventive potential of L. origanoides EOs and their major components, carvacrol and thymol.