[In vitro predatory activity of 8 fungal isolates against the nematode Panagrellus redivivus]. / Acción depredadora in vitro de ocho aislados de hongos contra el nematodo Panagrellus redivivus.

The aim of this study was to evaluate the predacious capacity in vitro of eight isolates of nematophagous fungi: four of Arthrobotrys sp., one of Arthrobotrys oligospora, one of Duddingtonia flagrans, one of Dactylaria sp. and one Monacrosporium eudermatum. Nine groups of Petri dishes with 13 repetitions each were set up. The fungi were seeded in fluor-corn-agar media, following this each Petri dish was added with 150 larvae of the free living nematode Panagrellus redivivus. Five days after larval addition these were collected by Baermannization and were quantified. A significant difference (p < 0.05) between all treated group was observed respect with the control. Isolates FTHO-8 D. flagrans, R6 M. eudermatum, DAC Dactylaria sp. as well as FTHO-4 and FTHO-6 Arthrobotrys sp., showed an excellent predatory activity (> 90%) and they could be considered as potential bio-control agents in future field trials.

[In vitro nematophagous capacity of Duddingtonia flagrans maintained under 2 conditions of preservation]. / Capacidad nematófaga in vitro de Duddingtonia flagrans Mantenido en dos Condiciones de Preservación.

One trial was carried out to evaluate the nematophagous capacity of two Duddingtonia flagrans cultures, one maintained during one year at laboratory temperature and the other one was a recent culture, twelve Petri dishes with flour-corn-agar media were seeded with the 1YC another 12 Petri dishes were inoculated with the RC. Both were added with 150 larvae/dish of the free living nematode Panagrellus redivivus and 12 fluor-corn-agar dishes only with the free living nematode were used as a control. The results showed that the nematophagous capacity of both cultures were similar but it was statistically different (p < 0.05) with respect to the control group. It was concluded that the nematophagous capacity of D. flagrans was not affected in spite of being kept one year at laboratory temperature.

[Evaluation of chemotherapeutic agents against cichlidogyriasis in tilapia (Oreochromis hornorum) in Mexico]. / Evaluación de quimioterapéuticos contra la ciclidogiriasis en tilapia (Oreochromis hornorum) en México.

To evaluate the efficacy of seven compounds against the cichlidogyriasis of tilapia fish (Oreochromis hornorum), two experiments were carried out. In one, 160 naturally infected fish with a mean burden of 33.4 parasites/animal were used. In another, 1600 fish with a burden of 49.9 parasites/fish were used. Fish were randomly divided into eight equal groups and received three treatments as submersion baths: methylene blue, malachite green, potassium permanganate, sodium chloride, formaldehyde, copper sulfate and triclorfon, and a non-treated control. Five days after the last treatment, all fish were killed and dissected to quantify the remaining parasites. All data were submitted to an ANOVA analysis. All groups compared to the control showed statistical difference (P < 0.01), with better efficacy at higher doses. Sodium chloride, potassium permanganate and triclorfon are highly efficient in the control of cichlidogyriasis of tilapia fish, but care should be taken with the toxicity of the two first compounds.

[Evaluation of 4 vermifuges against Bothriocephalus acheilognathi in carp]. / Evaluación de cuatro vermicidas contra Bothriocephalus acheilognathi en carpas.

With the aim to evaluate the efficacy of four vermicides, praziquantel, mebendazole, nitroscanate and triclorfon in the control of Bothriocephalus acheilognathi in carps, one hundred and sixty, two year-old carps (Ctenopharyngodon idellus) with an average weight of 120 g and a mean parasitic burden of 115.5 parasites/fish were used. Five groups of 30 fish each were randomly formed. Each group was then subdivided in three groups, each of 10 individuals/pond. The three subgroups of group A received 30, 50 and 70 mg/Kg of praziquantel, respectively. Groups B and C received 2.2, 4.4, and 6.8 mg/Kg of mebendazole suspension and mebendazole solution respectively; groups D and E received 10, 30, 50 mg/Kg; and 2.0, 4.0, 6.0 mg/Kg of nitroscanate and trichlorfon respectively. Group F of 10 fish remained as non-treated control. Praziquantel showed 100% of efficacy for all doses, therefore it was excluded from the statistical analysis. The subgroups B, C, D and E compared with the non-treated control were statistically significant (P < 0.01); showing in all treatments an additive effect, the higher the dose the better efficacy, except trichlorfon which showed a different tendency, having no explanation on that matter.