Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The current trend of change from soil cultivation to growing media cultivation involves generating materials having properties for optimal crop development in container. Vermicompost is a material produced for the action of earthworms in the decomposition of organic waste materials, which provides physical-chemical properties for the plants culture in pot, with the advantage of not polluting the environment. The aim of this study was to determine the optimal level of inclusion of vermicompost as a component of growing media for the production of Impatiens walleriana in container. Treatments of different inclusion percentages of vermicompost (100, 75, 50, 25, 0), mixed with a substrate prepared with equal parts of forest soil, coconut fiber and wood sawdust, were tested and compared with vermicompost alone and with chemical fertilization (200 ppm of 20-20-20 formula with microelements). The results showed that doses of vermicompost in the range of 75 % to 100 % allowed a good vegetative development presenting the highest averages in all measured variables. Treatment of 100 % of vermicompost obtained averages statistically similar with respect to Chemical treatment, in eight of twelve studied variables, and in remaining four treatments it was higher; so it was concluded that the dose of 100 % of vermicompost is the best treatment and can replace chemical fertilization in Impatiens walleriana potting. The characteristics of vermicompost as a substrate were porosity of 65.2 %, moisture retention of 53.4 %, electric conductivity of 4.12 dS·m-1 and pH of 6.9; the latter gave better results in growth of Impatiens walleriana in container.

The aim was to evaluate the effects of regeneration of chelipeds in molting and growth of male shrimp Cryphiops caementarius and to characterize the stages of regeneration of these appendices. Adult male shrimp captured in the Pativilca River (Lima, Perú) were used and selected in molt stage C, with complete cephalothoracic appendages, and no signs of lacerations on the body. The treatments were: autotomy of the major cheliped, autotomy of the minor cheliped, autotomy of both chelipeds and shrimp with intact chelipeds (control). Autotomy of chelipeds was induced by pressing with clamp the palm of the propodus to produce rupture. Eight stages of chelipeds regeneration before ecdysis were described for the first time. The major autotomized cheliped regenerated 58 % of its initial length and the minor cheliped regenerated 75.2 %. When both chelipeds were autotomized, the major chelipeds 41.3 % regenerated and minor cheliped 67.6 % regenerated. In all cases, regeneration occurred in the first post-autotomy molt. Autotomy of chelipeds significantly reduced (p<0.05) the period to 18 days in those with autotomy of both chelipeds, 26 and 28 days with a single cheliped autotomy, and control was 33 days. Autotomy of both chelipeds significantly reduced (p<0.05) weight gain (-21.67 %), followed by those who had the major autotomy cheliped (-11.12 %) and minor cheliped (-2.29 %); control growth was normal growing in 7.96 % by weight. According to the results, it is possible to infer the negative effect that autotomy of chelipeds would have in commercial culture of the species.

Ethnoichthyological studies are aimed to identify and record the relationships between human beings and fish. This type of studies are commonly performed in fishery communities with limited access to services, which increases their dependence to the biological realm surrounding them. Studies like this are scarce in Venezuela, hence their importance to record and preserve valuable information on popular traditions. The present study evaluated the ethnoichthyological knowledge of persons inhabiting fishery communities in Mochima National Park (MNP), aiming to prepare a written record that guarantees its preservation in time. Semistructured surveys were applied to a group of 214 persons. From them, 65.63 % practiced fishing as the main economic activity. In the zone, a total of 35 fish species were quoted as fishing targets. A group of 24 fish species had medicinal use and 28 species had diverse uses. Several of the quoted uses have not been previously recorded in the literature and belong to popular knowledge. They represent important contributions to the maintenance of the cultural traditions of inhabitants of fishery communities of MNP.

The experiment was made under laboratory conditions with the aim to evaluate the effect of sulphuric acid, boiling water and temperature on speed and percentage of emergence in Pithecellobium dulce (guamuchil), Leucaena leucocephala (guaje), and Sesbania sp (sesbania). Evaluated treatments were: immersion in suphuric acid (90 %), during 15, 30 and 45 minutes; immersion in boiling water; heating stove (70 %) and control. In guamuchil, the best percentage of emergence was obtained with sulphuric acid, immersion of 45 and 30 minutes. In guaje, the best percentage of emergence was provoked with immersion in sulphuric acid during 15 minutes. In sesbania, all three treatments of sulphuric acid were statistically equal amongst themselves and different from control. Treatment of immersion under boiling water during five minutes was prejudicial since there was no emergence. Finally, the heating of the seed in stove (70 °C) had no influence in the percentage of emergence of the seeds. Treatments with sulphuric acid obtained the highest velocity of emergence in the three evaluated species

The homegarden (HG) is an agro-ecosystemwith a prehistoric origin managed by women. The HG isimportant in the survival of large numbers of ethnic andpeasant groups and contains a considerable biologicaland cultural diversity. We inventoried the ethnoflora of15 HG, and interviewed their owners (13 women and2 men). Agrobiodiversity of HG is remarkable since 52botanical families, 118 genera, 146 species, 1 subspeciesand 13 varieties were recorded. Cultivated herbswith edible and ornamental use are the most common.Native and introduced species are 69 and 77, respectively.Most HG are handled by older women living alone, who make the decisions about theagro-ecosystem. The destination of production is consumptionof the household.

Lateral line description of Urotrygon rogersi was performed, which is composed by a series of sensorial canals of variable length, depending on the position of each canal, distributed on the dorsal and ventral sides of the body, the latter where the majority of canals are found. The hyomandibular canal possesses 9 dorsal innervations and 24 ventral ramifications. The morphological pattern observed in the lateral line is consistent with the Urotrygon group, nonetheless a detailed description of the lateral line of their congeners is necessary to analyze and discern specific patterns.

Pesticides are chemicals frequently used in agricultural pest control. Its uncontrolled and unplanned use has caused the development of resistance in different insect species. This review describes the phenomenon of resistance and its classification, aiming to highlight the major groups of enzymes known until now that are involved in the detoxification of pesticides in insects. Due to the importance that some enzymes mean, this review focuses on studies of resistance as glutathione S-transferases, acetylcholinesterase and P-450 cytochromes. In conclusion, the development of new studies that would deep knowledge in the cellular mechanisms and the enzymatic interaction in most insect species is necessary, since most of the current works focuses on a limited group of species. The latter meaning to improve pest control strategies of agricultural importance, with minimal environmental damage.

The dynamics of the ingestive behavior in grazing animals is especially dependent on the variety and variability of forage in the pasture. The objective of this work was to determine the productive and feeding behavior in hair sheep grazing in silvopastoral systems with Leucaena leucocephala and Cynodon plectostachyus in the humid tropics in Yucatan, Mexico. The silvopastoral system was evaluated in the rainy season (June to September of 2014) and dry season (December to February of 2015). The ingestive behavior of sheep grazing by direct observation of 7 to 17 hours, recording the time to grazing Cynodon plectostachyus (GCP), grazing of weeds (GW), browsing of Leucaena leucocephala (BLl), rumia standing (RS), rumination in the lying position (RL) and water consumption (WC). The grazing behavior of hair sheep was not affected by the time of year neither by the time of day (p>0.05). Similar behavior was observed (p>0.05) in the consumption of C. plectostachyus, L. leucocephala, weeds and the RS. Similarly, the time of day (morning or afternoon) did not affect the behavior of the sheep (p>0.05). However, most of the grazing time was devoted to the consumption of C. plectostachyus, weeds, RS, rest and water consumption at any time of the day in the two seasons evaluated. Was obtained DWG of 16.80 g and 28.35 g in the dry season and rainy season, respectively. It is concluded that the silvopastoral system with Leucaena leucocephala and Cynodon plectostachyus increases the time devoted to grazing of grasses and help maintenance of weight.

It has been shown that the isoform 2E1 of CYP 450 (CYP 2E1) and theta isoform of glutathione S-transferase (GSTT) are involved in the biotransformation of halomethanes (HMs) in mammals, which are disinfection by-products of water. In this study, a set of biomarkers related to exposure to these toxicants in the kidney of Goodea gracilis (a Mexican endemic fish) treated with CH2Cl2 (0.006, 0.03, 0.06, 0.06 and 6 mg L-1), CHCl3 (0.01, 0.1, 1, 10 and 100 mg L-1) and BrCHCl2 (0.002, 0.01, 0.1, 1, 10 mg L-1) were evaluated. Only activity of CYP 2E1 induced by BrCHCl2 and CH2Cl2 was higher than controls. GSTT metabolism and pro-oxidant forces (O2•, H2O2 and CH2O) were irregular regarding treatments and controls. Damage to cell membranes (ROOH and SRATB) showed a similar trend among the HMs. Protein oxidation was lower than controls except the one caused by the CHCl3. The CH2Cl2 stimulated the enzymes involved in the antioxidant defense (superoxide dismutase, catalase and glutathione peroxidase), as also occurred with total glutathione S-transferase, while the others HM elicited an irregular response. These findings suggest that toxic effects elicited by HM on the kidney of fish are complex and more studies are needed to expand knowledge on the subject.

During culture of native fish Dormitator latifrons, the presence of ectoparasite Argulus sp. was recorded. The signs associated with parasitism were: decreased food intake, erratic or violent swimming, overproduction of mucus, hyperemic lesions in the integument, integument deep abrasions, loss of fins and death. Argulus sp. prevalence was 100 % and mortality of the total population was 52 %. Treatment was performed with 0.3 ppm trichlorfon resulting in a prevalence of 0 %. Posttreatment fish developed normally. No new deaths associated with parasitosis or treatment were observed. It is recommended to establish a quarantine period of fish taken from the wild including chemical treatment with trichlorfon.