The paradox of the conservation of an endangered fish species in a Mediterranean region under agricultural intensification

We studied the relative value of natural habitats, river and coastal wetlands, and artificial habitats, irrigation canal and ponds, for the conservation of an endangered fish, Iberian toothcarp, in its southernmost area of distribution, characterised by agricultural intensification. Our results show that the bulk of the population of the Iberian toothcarp is concentrated in irrigation ponds. Natural habitats sustained null or impoverished subpopulations, and individuals showed signs of low metabolic activity. This coincided with the relatively high habitat quality observed in ponds, particularly those with submerged aquatic vegetation, in contrast with the chronic eutrophication of the coastal lagoons. In spite of a generalised aggressive management in the irrigation system, featured by periodic vegetation clearance, desiccation and biocide treatment, the subpopulation of the Iberian toothcarp thrives in it probably thanks to adequate water quality and to an active path dynamics maintained by connectivity through the canal. Agro-environmental measures are discussed for the improvement of this species conservation in natural and artificial habitats.     

Antibacterial activity of Rhizophora mangle bark.

The aqueous extract of Rhizophora mangle bark, also formulated to ensure physical and chemical stability, was found to inhibit the growth of seven bacteria frequent in infected wounds.     

COX-2 and sPLA2 inhibitory activity of aqueous extract and polyphenols of Rhizophora mangle (red mangrove)

The aqueous extract of Rhizophora mangle bark and its polyphenolic fractions showed remarkable in vitro antiinflammatory activity in a preliminary study. The low molecular weight fraction exhibited cyclooxygenase-2 inhibitory activity while the total aqueous extract and the low molecular weight fraction showed secretory phospholipase A(2) inhibitory activity.     

Pond management and water quality for drip irrigation in Mediterranean intensive horticultural systems

The influence of pond management on water quality for drip-irrigated crops was studied throughout a field survey and a mesocosm experiment. Water sources were pooled into two groups: ground or surface water (GW/SW) and recycled wastewater. Pond covering, which was limited to about a quarter of them, improved water quality by reducing phytoplankton biomass. However, biocide applications and pond dredging were ineffective at improving in-pond water quality. Dredging did not reduce the concentrations of planktonic chlorophyll a or total suspended solids (TSS) in GW/SW fed ponds, whereas biocide applications increased both parameters. Field and experimental data proved that the two predominant taxa of submerged aquatic vegetation (SAV) found in ponds (Potamogeton pectinatus and Chara spp.) improved water quality by increasing water oxygenation and decreasing chlorophyll a and TSS concentrations. Preserving SAV (especially Chara spp.) appears to be an environment-friendly, cost-effective and recommendable alternative strategy for irrigation pond management.     

Inducement of sex reversal in Sarotherodon niloticus (Linnaeus)

Two androgens, ethynyltestosterone (ET) and methyltestosterone (MT) and two estrogens, diethylstilbestrol (DES) and estrone (E) were orally administered to gonadally undifferentiated Sarotherodon niloticus fry. Diets with hormones were prepared at the following levels: ET and MT at 30 and 60 mg kg^?1 of feed, DES at 25 and 100 mg kg^?1 of feed, and E at 100 and 200 mg kg^?1 of feed. The fish were fed at 10% body weight per day for 25-, 35- and 59-day periods.All-male populations were produced with ET-60 and MT-60 in all three treatment periods, and with ET-30 and MT-30 during the 35- and 59-day treatments.No estrogen treatment resulted in 100% female populations but only about 10% of the DES-100 treatment populations at the three durations were males.Sex ratios were significantly different (P < 0.01) from the expected 1:1 ratio in all fish treated with androgens and estrogens. No ovotestis condition was found. Total mortalities in all treatments and controls were uniformly low, ranging from 1.5 to 8.8% for the treatment period.     

Selected nutritional and quality analyses of tomatillos (Physalis ixocarpa)

Proximate composition, total dietary fiber and pH of tomatillos (Physalis ixocarpa) grown in Baja, California were analyzed. Moisture content averaged 92%. On a dry matter basis (DMB), tomatillos contained 11% protein, 18% fat, 13% ash and 5% total dietary fiber. On an as consumed basis (ACB), tomatillos contained 1% protein, 1.5% fat, 1% ash and 0.4% dietary fiber. Carbohydrate (CHO) content was calculated by difference resulting in an average adjusted CHO (excluding dietary fiber) of 53% on a DMB and 4% on an ACB; total CHO (including dietary fiber) was 58 and 4.8%, respectively. Average kcalorie content was calculated to be about 31 kcals/100 g. The average pH of tomatillos was 3.76.     

Interactive effects of shade and irrigation on the performance of seedlings of three Mediterranean Quercus species

Shade and irrigation are frequently used to increase the success of Mediterranean Quercus spp. plantations. However, there is controversy about the combined effects of these treatments on plant performance. We assessed the effects of two irradiances (full sunlight and moderate shade) and two summer watering regimes (high (daily) and low (alternate days)) on leaf and whole-plant traits of 1-year-old seedlings of Quercus coccifera, Q. ilex subsp. ballota and Q. faginea grown outdoors for 8.5 months. Leaf traits included measures of morphology, nitrogen concentration, gas exchange and photochemical efficiency, and measures of whole-plant traits included biomass allocation patterns, growth phenology, across-summer leaf area change and relative growth rate (RGR). Moderate shade reduced leaf mass per area, increased photochemical efficiency, maximum carbon assimilation rate (Amax) and allocation to leaves, and prolonged the growing period in one or more of the species. Daily watering in summer increased Amax of Q. ilex and prolonged the growing period of Q. ilex and Q. faginea. Both treatments tended to increase RGR. The effect of shade was greater in the low-watering regime than in the high-watering regime for two of the 15 studied traits, with treatment effects being independent for the remaining 13 traits. Leaf nitrogen and the ability to maintain leaf area after the arid period, rather than biomass allocation traits, explained the variation in seedling RGR. Trait responsiveness to the treatments was low and similar among species and between study scales, being unexpectedly low in Q. faginea leaves. This may be because selective pressures on leaf plasticity act differently in deciduous and evergreen species. We conclude that moderate shade and daily summer watering enhance the performance of Mediterranean Quercus seedlings through species-specific mechanisms.     

Antioxidant activity of Rhizophora mangle bark

The antioxidant activity of Rhizophora mangle bark aqueous extract and its majoritary component and high molecular weight polyphenols' fraction were studied using deoxyribose assay. The total extract and its fraction showed scavenging activity of hydroxyl radicals and hability to chelate iron ions.     

Growth and immune response of giant freshwater prawn Macrobrachium rosenbergii (De Man) postlarvae fed diets containing Chlorella vulgaris (Beijerinck)

A 50‐day growth trial was conducted to evaluate the efficacy of Chlorella vulgaris (Beijerinck) as an ingredient in the diets of giant freshwater prawn Macrobrachium rosenbergii (De Man) postlarvae (PL30). Immune response (total haemocyte count and prophenoloxidase activity) was also assessed by subjecting postlarvae to a challenge test against Aeromonas hydrophila (Chester) for 14 days. Iso‐nitrogenous and iso‐lipidic test diets were prepared using a fishmeal‐based‐positive control diet (D0) and four basal diets with inclusion levels of 2% (D2), 4% (D4), 6% (D6) and 8% (D8) C. vulgaris. Postlarvae of M. rosenbergii were randomly stocked (mean initial body weight of 0.19 ± 0.02 g) in 30‐L tanks in three replicates per dietary treatment for evaluation of growth performance. Another set of postlarvae (mean initial body weight of 1.25 ± 0.02 g) was randomly distributed in 95‐L tanks in three replicates per dietary treatment for the assessment of immune response. Results showed that specific growth rate was significantly higher (P < 0.05) in postlarvae fed D4 and D6. Variations in values for carcass protein, lipid, moisture and ash were also evident. Postlarvae fed diets with Chlorella showed increased prophenol oxidase activity and total haemocyte counts. Moreover, survival rate after challenge with A. hydrophila was significantly increased (P < 0.05). Inclusion of C. vulgaris in diets enhanced immune response and resistance of M. rosenbergii postlarvae against A. hydrophila infection.     

Efficacy of Rhizophora mangle aqueous bark extract in the healing of open surgical wounds

Thirty-seven patients with open wounds from surgical intervention of pilonidal cyst (14; 37.8%) or pilonidal fistula (23; 62.2%) were enrolled on a voluntary basis in a comparative blinded clinical trial and randomly assigned to a topical treatment with a Rhizophora mangle aqueous bark extract once a day or twice a day or mercurocrome twice a day. The efficacy of the treatments was evaluated weekly from day 10 to 12 until 6 weeks after surgery by measuring the area of the wounds by image digital planimetry and the tolerability by recording adverse effects. The initial size of the wounds was taken in consideration as covariable in the Generalized Lineal Model used. A thin dark red colored film covering the wound was observed in all the cases treated with the extract. The wound areas of the groups treated with the extract once or twice per day showed a greater reduction (P < 0.05) compared to the group treated with mercurocrome. No differences between the two regimes of application of the extract of R. mangle were observed. No subject showed any sign of adverse effects and no secondary infections were observed.