A Chemical Selectively Lethal to Squawfish (Ptychocheilus oregonensis and P. umpquae)

Abstract

A piscicide, 1,1′‐methylenedi‐2‐naphthol, is lethal to Ptychocheilus oregonensis and P. umpqua at concentrations 3 to 100 times more toxic to squawfish than to salmonids. Selectivity of the chemical varies with the tolerances of the species and its potency varies positively with concentration and temperature. For a thermal range of 18.3 to 10.0 C, the minimum LC100 is 0.006 to 0.015 ppm for P. oregonensis and 0.01 to 0.03 ppm for P. umpquae. Within these ranges the mean survival time varies from 6 to 31 hr for P. oregonensis and 6 to 20 hr for P. umpquae. In 96‐hour assays at similar temperatures, the maximum LC0 is about 0.3 ppm for Salvelinus fontinalis, 0.1 ppm for Oncorhynchus tshawytscha, and from 0.6 to 1.3 ppm for O. kisutch and Salmo gairdneri depending on the water temperature. One domestic sheep and two ducks showed no ill effects when forced to drink water containing 10 ppm of the chemical for 1 week. A field application in a small lagoon containing several species of fish killed only P. oregonensis.

Mechanistic investigation inspired “on water” reaction for hydrobromic acid‐catalyzed Friedel–Crafts–type reaction of β‐naphthol and formaldehyde

“…This outcome is consistent with the computational results suggesting that the solvent effect of water can assist the transformation. It maybe due to the low solubility of product in water, the yield of Pr in water is slightly lower than that in MeCN (99%), but this F‐C type reaction can be successfully achieved “on water” with high yield, and water can be recycled. This is responsible for the following reasons: water is a polar molecule that can work as a hydrogen‐bond donor and/or acceptor .…”

Chloroquine and hydroxychloroquine in the environment and aquatic organisms: a review

“…This can help to reproduce and understand possible environmental scenarios related to the indiscriminate use of drugs in 2020. A reflection of that was the concentration observed in surface water by Nason et al (2021), Cappelli et al (2022) and Domingo-Echaburu et al (2022), which promotes changes in biomarkers of oxidative stress, neurotoxicity (acetylcholinesterase and neuromasts), decreased levels of total proteins and death in vertebrates (MacPhee and Ruelle, 1969;Luz et al, 2021;Mendonça-Gomes et al, 2021).…”

Oxidative degradation of the piscicide squoxin in aerated river water

“…1,1 '-Methylenebis(2-naphthol) (squoxin, 1) was found by MacPhee and Ruelle (1969) to be a selective piscicide against the northern squawfish (Ptychocheilus oregonensis). Johnston (1972) described its effectiveness at concentrations in water as low as 6 ppb and also its lack of effect on desirable fish at concentrations up to 1 ppm.…”