Leukocyte response and phagocytic activity in Nile tilapia experimentally infected with <Emphasis Type="Italic">Enterococcus</Emphasis> sp.

This study evaluated the total and differential leukocyte counting and the phagocytic activity in Nile tilapia Oreochromis niloticus experimentally injected with Enterococcus sp. in the swim bladder. Fish were distributed in four treatments in triplicates of non-injected fish, fish injected with 1 ml of sterile saline solution 0.65%, and fish injected with 1 × 10³ and 1 × 10⁶ colony-forming units (CFU) of Enterococcus diluted in 1 ml sterile saline. Twenty-four hours after injection, the fish were anesthetized and the blood collected for white blood cell (WBC) counts, differential counting of WBC, and phagocytic activity of blood leukocytes. The increased numbers of WBC and lymphocytes were followed by decreased number of monocyte after infection. The percentages of phagocytic activities in the blood were 55.3 and 55.9%, respectively, in tilapia injected with 1 × 10³ and 1 × 10⁶ CFU/ml.     

Remarks on genetic diversity and relationship of <Emphasis Type="Italic">Punica protopunica</Emphasis> and <Emphasis Type="Italic">P. granatum</Emphasis> assessed by molecular analyses

Here, two Punica species, viz., P. protopunica Balf. fil., reported as native to Socotra, and P. granatum L., were compared for the first time. Analysis of one P. protopunica and eleven P. granatum accessions was performed using three molecular markers, i.e., sequence related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP), and intron targeted amplified polymorphism (ITAP), along with analysis of pgWD40 sequences, a gene involved in anthocyanin biosynthesis. All markers revealed the relationship between the two species and placed them at 33% similarity. SRAP, TRAP, and ITAP generated a total of 299, 260, and 160 bands, respectively. Of these, 78, 74, and 41 bands were specific for P. protopunica, and 92, 85, and 57 bands, respectively, were shared between both species. Sequence analysis of pgWD40~870 bp amplicons exhibited 100% identity among P. granatum accessions and 98% identity to that of P. protopunica. Phylogenetic analysis of WD40 sequences from monocot and dicot species, including both Punica species confirmed the relation between P. protopunica and P. granatum, supporting earlier reports that P. protopunica could be an ancestral species of P. granatum. Furthermore, the genetic diversity among and within P. granatum accessions from Egypt (3), Mexico (5), and Yemen (3) was assessed. Molecular marker-based relationships among region-bulked accessions was approximately the same (~90% similarity), whereas the degree of genetic variation was altered within each region. Specific bands (alleles) for accessions of each region along with those shared among them were identified. Thus, these bands could be used for pomegranate genotyping and breeding programs.     

Integrated production of fish (pacu <Emphasis Type="Italic">Piaractus mesopotamicus</Emphasis> and red tilapia <Emphasis Type="Italic">Oreochromis</Emphasis> sp.) with two varieties of garnish (scallion and parsley) in aquaponics system

Aquaponics is emerging as an alternative for high-health food production. Being able to identify the technical viability of non-conventional plants and fish species would help to increase the interest and possibilities in aquaponic systems. The goal of the present study was to evaluate the aquaponics production of two garnish species: scallion (S) and parsley (P), using effluents of pacu and red tilapia culture. Two aquaponics devices were used, differing according to the fish species, generating two different effluents. Thus, for plant performance, four treatments were evaluated in a factorial design (plant species and fish effluent as main factors), as followed: Pacu-S, Tilapia-S, Pacu-P, and Tilapia-P, with three replicates each, for 35 days. Fish performance was evaluated using Student’s t test. Each experimental device included a fish tank, filters, and six experimental units for the plants (floating rafts). Results indicated that feed conversion ratio (FCR) was higher in tilapia as compared to pacu (p < 0.05); however, fish productivity and survival were similar between species. Plant performance parameters were similar with no significant differences regardless of the fish effluent (p > 0.05), except for higher number of leaves per plant in scallion cultured using pacu effluent. Plant performance comparing both plant species indicated that scallion performed better as compared to parsley in all parameters. In addition, scallion also performed better related to the plant quality index. The results indicate that pacu presented a viable alternative for the aquaponics production, and regarding to the garnish, scallion performed better results as compared to parsley.     

Digestive enzyme activity in the intestine of Nile tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis> L.) under pond and cage farming systems

The effect of different farming systems (cage, pond) upon digestive enzyme activities of Nile tilapia was evaluated. Juvenile Nile tilapia (87.61 ± 1.52 g) were simultaneously cultured in pond and cage systems during 90 days. Cages used nutritional biphasic plan (35 and 32 % crude protein—CP feeds) and ponds used nutritional triphasic plan (35, 32 and 28 % CP feeds). Biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the performance of enzyme activities. Total proteolytic, amylase and lipase activities were not statistically different between the treatments throughout the periods analyzed (31, 63 and 94 days of culture). However, trypsin and chymotrypsin activities were higher with 31 and 63 days of culture in fish from pond system, suggesting that natural food may have influenced these activities. A positive correlation was observed between the recommended concentration of essential amino acids for Nile tilapia and specific aminopeptidases activity in fish cage system. Substrate–SDS–PAGE revealed 12 active proteolytic bands in both systems. However, integrated density (ID) values were higher in the bands of ponds. Specimens of either cage or pond exhibited five bands of amylolytic activity. Fish from cage and pond systems showed the highest values of ID within 31 days of cultivation. In this study, the complexity of digestive functions could be verified for animals maintained under commercial conditions. Some of the assessed enzymes may show adaptations of their activities and/or expression that allow the fish to achieve a more efficient nutrient assimilation.     

Structural Characterization of New Peptide Variants Produced by Cyanobacteria from the Brazilian Atlantic Coastal Forest Using Liquid Chromatography Coupled to Quadrupole Time-of-Flight Tandem Mass Spectrometry

Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.).     

Mercury in Biota and Surficial Sediments from Coatzacoalcos Estuary, Gulf of Mexico: Distribution and Seasonal Variation

Variation of mercury (Hg) in sediments and biota from Coatzacoalcos estuary during the dry, rainy and windy seasons was estimated. In sediments, Hg concentrations ranged from 0.07 μg g^?1 in site 13 (Ixhuatepec) located upstream, to 1.06 μg g^?1 in site 3 (Coatzacoalcos river), located in the industrialized area. Highest enrichment factor (EF) and index of geoaccumulation (I _geo) in surficial sediments were 53 and 5.1 respectively. From EF and I _geo, it is considered that Coatzacoalcos estuary is from moderately contaminated to contaminated. In most fish species from Coatzacoalcos estuary, the sequence of Hg concentration was liver>muscle>gills. Average Hg concentrations in soft tissue of bivalves ranged from 0.09 μg g^?1 in Corbicula fluminea to 0.18 μg g^?1 in Polymesoda caroliniana. Biota-sediment accumulation factor (BSAF) ranged from 0.9 in P. caroliniana during the rainy season (site 4) to 3.8 in P. caroliniana from the same site during the windy season.