Mushrooms to live or die: toxicity of some Basidiomycota using Artemia franciscana.

Consumption of wild mushrooms has increased in recent years; however, not all of them are edible and there is no precise information on those that may cause poisoning. Therefore, studies to obtain data about their toxicity are needed. For this purpose, we used the brine shrimp Artemia franciscana, a crustacean employed in toxicity tests and with wide application in the toxin detection, including mycotoxins. Mushrooms were collected in the state of Jalisco, Mexico, with which aqueous extracts were prepared. Dilutions of the stock solution of each extract were made to final concentrations of 50, 100, 250, 500, and 1000 µg/mL. Potassium dichromate (PD) was used as positive control and artificial seawater as negative control. The median lethal dose (LD50) of extracts on nauplii of A. franciscana was calculated. The aqueous extracts obtained from Amanita amerivirosa, A. muscaria, Chlorophyllum molybdites, and Leucopaxillus amarus showed a LD50 < 70 µg/mL, similar to PD (LD50 = 37 µg/mL). This is the first indication of the probable toxicity of Leucopaxillus amarus in humans. Cantharellus cibarius and Scleroderma texense caused the lower toxicity to the nauplii. The brine shrimp bioassay was effective in evaluating the toxicity of Basidiomycota. Scleroderma texense has been reported to be toxic, but it was not for this crustacean nauplii, and probably not to humans either, as recent literature has reported.

Putting the Pacific fat sleeper Dormitator latifrons (Pisces: Eleotridae) to sleep: effects of clove oil and lidocaine anesthetic.

Among the different handling techniques in aquaculture, the use of anesthetics has had a growing interest focused on guaranteeing animal welfare, and reducing possible stress situations during general handling. The aim of this study was to present the use of eugenol and lidocaine with non-invasive anesthesia procedures in Dormitator latifrons, in which the different stages of anesthesia (induction and recovery) were determined. One hundred and twenty healthy fish of average weight of 73.59 ± 13.53 g and standard length of 17 ± 1.36 cm were used. The experimental fish were subjected to fasting for 24 h prior to the tests. Five fish were subjected to eugenol (25, 50, 100, and 200 µL/L), and lidocaine (100, 200, 300, and 400 mg/L), in triplicate. The time to reach deep and recovery anesthesia were recorded and the data analyzed using ANOVA (α= 0.05). Organisms exposed to anesthetics evidenced early episodes of fast, short-distance swimming (initial hyperactivity) for short periods of time. Survival was 100% with both compounds and concentrations. Fish exposed to a eugenol concentration of 200 µL/L had longer anesthesia times and took longer time to recover (P<0.05). The most effective concentrations for eugenol and lidocaine were of 200 µL/L and 400 µL/L in juvenile fish, promoting rapid inductions, without compromising the conditions for the recovery of the fish. This work provides practical information for handling and transportation D. latiforns with the least possible stress and ensuring animal welfare.