Prebiotic,probiotic, and synbiotic in the diet of Nile tilapia post-larvae during the sex reversal phase

This study evaluated the use of the prebiotic Active-MOS® (mannanoligosaccharides—Biorigin®) and two probiotics: PAS-TR® (Bacillus subtilis and Bacillus cereus var. toyoi—Imeve®) and Bioplus 2BC® (1.6 × 10¹⁰ UFC g^?1 de Bacillus subtilis and 1.6 × 10¹⁰ UFC g^?1 Bacillus licheniformis—Christian Hansen®) tested separately and together, in the diet of Nile tilapia post-larvae during the sex reversal phase. The experiment was conducted in two stages: (i) a total of 2160 3-day-old post-larvae (PL) (10.39 ± 0.85 mm and 12.28 ± 3.15 mg) were used and distributed in 24 tanks of 40 L each (3.0 PL L^?1). Growth performance, chemical analysis of carcass, bacterial recovery, and histomorphometry of intestinal villi were evaluated; (ii) 240 tilapia (4.28 ± 0.19 cm and 1.19 ± 0.09 g) from the previous experiment were used and stocked at 10 PL per aquarium. The parameters evaluated were survival and relative protection level after bacterial challenge against Aeromonas hydrophila. Six treatments with four replications in a completely randomized design were used for both experimental stages. Additives in the diet of tilapia post-larvae did not determine significant differences in growth, survival, microbiological, or histomorphometric parameters in this study. Nevertheless, after the experimental infection, advantages on the use of the additives were observed in terms of higher relative protection levels (38.10%) and relative percent survival in fish receiving Active-MOS® + Bioplus 2BC®. Therefore, we recommend the use of synbiotic (Active-MOS® + Bioplus 2BC®) in the farming of Nile tilapia PL with recurrent outbreaks of bacterial diseases during the sex reversal phase.     

European seabass (Dicentrarchus labrax) ability to discriminate between diets made with different dietary fat sources

The aim of this work was to determine whether juvenile and adult European seabass (Dicentrarchus labrax L.), fed ad libitum manually and with self‐feeding demand feeders, respectively, were able to discriminate between a fish oil‐based diet and a series of diets made with vegetable oils (soybean, linseed, rapeseed and sunflower oil), as well as a fat‐free diet. Adult D. labrax (443.6 ± 108.8 g) selected diets made from soybean (SYO) and rapeseed (RO) in proportions similar to fish oil (FO). Demand levels for the other two diets, sunflower (SUO) and linseed (LO) oils, were significantly lower than FO, whilst juveniles (56.4 ± 11.2 g) displayed a preference for SYO and FO. The lowest demand levels were associated with a fat‐free diet (FF). Selection percentages of the diets for adult and juvenile fish were, respectively, FF—22.96% and 39.76%, SYO—43.02% and 53.26%, LO—36.48% and 36.19%, SUO—39.87% and 37.32%, and RO—46.38% and 40.94%. The animals’ size and feeding method did not significantly affect dietary selection. However, a statistical difference in specific growth rate (1.37% ± 0.26% day^?1) for juveniles was only observed for FO+FF combination. For juveniles, no differences were observed in the conversion index. The juvenile group (FO + FF) had the highest food intake (2.00 ± 0.35 g 100 g^?1 body weight). Moreover, the groups fed FO + SUO and FO + RO consumed the least. In conclusion, this study shows D. labrax can discriminate between diets where the only difference is the lipid source. These findings should be used to understand the acceptance or rejection of different source oils, which are increasingly being used in aquaculture such as aquafeeds for European seabass.     

Experimental culture of larvae,post‐larvae and juveniles of the West Indian top shell,Cittarium pica (Linnaeus 1758)

The West Indian top shell, Cittarium pica, is an endangered vetigastropod of ecological and commercial value from the Caribbean. In order to assess the use of aquaculture as a tool for its sustainable production and conservation, embryos were produced in hatchery and experimentally cultured until juveniles under different conditions. Embryos were incubated under two temperatures (25 and 29°C) and six densities (0.3, 0.6, 1.0, 4.0, 9.0 and 37.0% of bottom‐coverage). Larvae were reared under different temperatures (25 and 27°C), densities (0.5, 1, 1.5 and 10 larvae/ml) and culture systems (static and down‐welling). Post‐larvae were obtained in three different settling conditions, and the early juveniles were cultured supplying fresh seaweed (Laurencia obtusa and Padina gymnospora), natural multi‐specific biofilm and Cylindroteca sp. biofilm. The growth and survival of embryos and larvae were not affected by temperature, but they were affected by density. Higher values were obtained at low densities (<1% of embryos bottom‐coverage and <1 larvae/ml), except for the growth of larvae, which was similar among treatments. Higher larval survival was recorded using the static culture system, and higher percent of post‐larvae recovered was associated with lower density of crawling veliger (0.2 and 0.1/ml), while its higher growth rate was related to the use of biofilms with conspecific mucus and low water‐flow (50%/h). The type of food tested did not affect the juvenile growth, but higher survival was obtained in those fed with seaweed than with multi‐specific biofilm.     

The impact of conservation on the status of the world's vertebrates

Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.     

Functional characterization of FaCCD1: a carotenoid cleavage dioxygenase from strawberry involved in lutein degradation during fruit ripening

A gene encoding a carotenoid cleavage dioxygenase class 1 enzyme (FaCCD1) was identified among a strawberry fruit expressed sequence tag collection. The full-length cDNA was isolated, and the expression profiles along fruit receptacle development and ripening, determined by quantitative real time polymerase chain reaction, showed that FaCCD1 is a ripening-related gene that reaches its maximal level of expression in the red fully ripe stage. FaCCD1 was expressed in Escherichia coli, and the products formed by the recombinant protein through oxidative cleavage of carotenoids were identified by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analyses. The FaCCD1 protein cleaves zeaxanthin, lutein, and beta-apo-8'-carotenal in vitro. Although beta-carotene is not a good substrate for FaCCD1 in vitro, the expression of FaCCD1 in an engineered carotenoid-producing E. coli strain caused the degradation of beta-carotene in vivo. Additionally, the carotenoid profile in strawberry was analyzed by high-performance liquid chromatography-photodiode detection, and a correlation between the increase of the expression level of FaCCD1 during ripening and the decrease of the lutein content suggests that lutein could constitute the main natural substrate of FaCCD1 activity in vivo.     

Soil application of meat and bone meal. Short-term effects on mineralization dynamics and soil biochemical and microbiological properties

Meat and bone meal (MBM) utilization for animal production was banned in the European Union since 2000 as a consequence of the appearance of transmissive spongiform encephalopathies. Soil application could represent a lawful and effective strategy for the sustainable recycling of MBM due to its relevant content of nutritive elements and organic matter. The effectiveness of MBM as organic fertilizer needs to be thoroughly investigated since there is a lack of knowledge about the mineralization dynamics of MBM in soil and the impact of such residues, in particular the high content of lipids, on soil biochemical and microbiological properties. For this aim, a defatted (D) and the correspondent non-defatted (ND) MBM were added at two rates (200 and 400 kg N ha^?1) to two different moist soils and incubated at 15 and 20 °C for 14 d. MBM mineralization dynamics was studied by measuring CO₂ evolution. Water extractable organic C, K₂SO₄-extractable NO₃^? and NH₄⁺, microbial biomass ninhydrin-reactive N, enzymatic activities (FDA, urease, protease, alkaline phosphatase) and microbial composition (aerobic and anaerobic bacteria, fungi) were measured 2 and 14 d after MBM addition to the soil. The rate of CO₂ evolution showed a maximum 2–3 d after the addition of MBM, followed by a decrease approaching the control. MBM mineralization was fast with, on average, 54% of total CO₂ evolved in the first 4 d of incubation at 20 °C. The percentage of added C which was evolved as CO₂ at the end of the incubation period ranged between 8% and 16% and was affected by temperature, soil type and MBM treatment (ND > D). Soil amendment with MBM caused a noteworthy increase in both extractable NH₄⁺ and NO₃^? (about 50% of added N) which was higher for ND. The addition of MBM also enhanced microbial content and activity. Microbial biomass increased as a function of the rate of application and was higher for ND with respect to D. The increase in numbers of aerobic and anaerobic bacteria and fungi caused by MBM addition was, in general, more pronounced with ND. Enzymatic activity in amended soils showed an enhancement in nutrient availability and element cycling. At the rate of application of present work, lipids did not cause adverse effects on soil microorganisms.The potential of MBM as effective organic fertilizer was supported by the large increase in available N and the enhancement of the size and activity of soil microorganisms.     

Pollutants in drainage channels following long‐term application of Mancozeb to banana plantations in southeastern Mexico

The aim of this study was to investigate how long‐term Mancozeb application to banana plantations affects the occurrence of pollutants in drainage‐channel sediment and water under tropical conditions. We estimated the possible accumulation of Mancozeb's principal metabolite ethylenethiourea (ETU), as well as manganese (Mn) and zinc (Zn) as components in channel sediment and water. We took samples during the tropical‐rainfall season and the low‐rainfall season. For sediment samples, we determined the contents of ETU, Mn, and Zn. For water samples, we determined the concentration of ETU. Additionally, we took water samples from a runnel that is the receiving body of hydraulic flow from the system. In both seasons, ETU in the sediment was near the detection limit (0.01 mg kg^–1) and did not show any accumulation. However, Mn in sediment at all sampling sites exceeded the threshold values for aquatic life of 630 mg kg^–1 with values between 635 and 7256 mg kg^–1. The Zn concentrations in sediment varied from 87 to 190 mg kg^–1 and exceeded the threshold values for aquatic life of 98 mg kg^–1 at several sites. Furthermore, we determined an accumulation of these heavy metals in the sediments of the banana‐planted zone in comparison with sediments in pasture reference sites. In contrast to the low concentration of ETU in sediment, its concentration in drainage and runnel water (5.9–13.8 μg L^–1) exceeded the EU threshold value for drinking water (0.1 μg L^–1) by up to nearly 140 times. However, the threshold value for aquatic life was not exceeded. We conclude that long‐term Mancozeb application does lead to a severe accumulation of Mn in sediments and of ETU in surface water. New strategies should be used to control black Sigatoka, including integrated methods of pest control so that long‐term negative effects on the environment can be avoided.     

Erysiphe diffusa causing powdery mildew on Mimosa caesalpiniifolia in Brazil: A soya bean pathogen found on an important native Brazilian tree

Mimosa caesalpiniifolia: Fabaceae (sansão‐do‐campo or sabiá, in Brazil) is a small tree or shrub native to the Brazilian semi‐arid forest and widely used as a hedge plant in Brazil. Although of economic relevance, little is known of fungal pathogens infecting this plant. Recently, plants growing in an urban situation at Ouro Preto, and also on the roadside in Viçosa (state of Minas Gerais, Brazil), were found to be severely attacked by a powdery mildew which led to progressive leaf blight and serious defoliation. Based on morphology and molecular phylogenetic analysis of nuclear rDNA sequences, the fungus was identified as Erysiphe diffusa—a pathogen best known attacking soya bean, particularly in highland plantings.     

Effects of temperature and photoperiod on the conditioning of the flat oyster (Ostrea edulis L.) in autumn

The production of the flat oyster Ostrea edulis (L.) natural spat in Europe has decreased almost by 60% in the past ten years. Thus, the importance of the production of oyster spat in hatcheries is evident. One of the critical steps in hatchery production is broodstock conditioning, especially difficult in autumn, when gonadal development is in resting period. Conditioning is influence by temperature, photoperiod and nutrition. In this work, the effects of two temperature and three photoperiod regimes on the conditioning of O. edulis were studied for three years by stereological analyses and registering number and dates of spawning and larval yield. Temperature had a positive effect on the gonadal development of O. edulis during conditioning. The percentages of germinal cells in oysters conditioned with a gradient of temperature (14–18°C) were double compared to oysters conditioned at 15°C. Oysters conditioned with longer photoperiods showed higher percentages of germinal cells. There was no interaction between temperature and photoperiod. Spawning was observed in the oysters treated with daylight (8–16 h) ten weeks from the beginning of conditioning. Flat oysters conditioned with 8 h and 8–12 h of daylight delayed the first spawning for a month. Total larval production was higher in the oysters treated with the longest daylight gradient. Gonadal and gametogenic development was a non‐synchronic process and the spawning extended for around two months. A protocol for flat oyster broodstock conditioning in autumn by using both a gradient of temperature (14–18°C) and daylight (8–16 h) is proposed.