Reduced Formalin and Hydrogen Peroxide Treatments during Walleye Egg Incubation

Abstract

Formalin use was evaluated as part of an investigational new animal drug study to determine its effectiveness in controlling fungus (water molds: Saprolegniaceae) on incubating eggs of the walleye Sander vitreus. Hydrogen peroxide was also evaluated as an egg treatment alternative to formalin. In total, three antifungal chemical treatment regimes (15 min daily) were evaluated during this study. Eggs were treated with 200 mg of hydrogen peroxide/L of water, 834 mg formalin/L, and the industry standard of 1,667 mg formalin/L. Untreated control eggs were severely infested with fungus and experienced survival to hatch that was significantly lower than that of the chemically treated eggs. Formalin and hydrogen peroxide treatments both controlled fungus and produced similar egg survival to initial hatch. However, walleye egg survival was significantly greater in jars treated with 1,667 mg formalin/L than in any other treatment. This study provided important new data on the use of chemical treatment concentrations lower than the standard of 1,667 mg formalin/L or 500 mg hydrogen peroxide/L to control fungus on incubating walleye eggs.

Acute toxicity of three antifungal chemicals on silverside Odontesthes bonariensis (Valenciennes 1835) eggs

“…Formalin concentration of 1000 mg L -1 was fungicidal but a concentration of 250 mg L -1 might have a fungistatic effect, being the efficacy progressively increased after longer exposures (Marking et al, 1994). Our 96 h LC 50 (652.14 μL L -1 ), NEC (530 μL L -1 ) and NOEC (400 μL L -1 ) values are within the recommended range for their application as fungicide in other species (Soupir and Barnes, 2006); those concentrations of F are equivalent to 241.3 mg L -1 and 196.1 mg L -1 of formaldehyde, respectively. These results agree with those reported by Khodabandeh and Abtahi (2006) who found that optimal concentration to control fungal infection in Cyprinus carpio eggs was 400 mg L -1 .…”

Evaluation of Two Formalin Concentrations During Yellow Perch Egg Incubation

“…Because both formalin treatment concentrations used in this study controlled fungal growth, using only 834 mg/L instead of 1667 mg/L would reduce chemical costs, decrease the risk to worker health (Marking et al, 1994;Voorhees & Barnes, 2016), and reduce potentially problematic formalin discharges into hatchery effluents (Masters, 2004). Formalin treatment concentrations of 834 mg/L have also been effective during the incubation of other percid eggs (Soupir & Barnes 2006). Barnes and Soupir (2007) were also able to reduce formalin treatment concentrations from 1667 mg/L to 1000 mg/L during rainbow trout Oncorhynchus mykiss egg incubation with no impact on fungal growth or egg survival.…”

“…The results from experiments with formalin treatments on incubating percid eggs are far from uniform. Although Abd El-Gawad et al (2015) and Hart et al (2006) observed positive effects from treating perch eggs with relatively low formalin concentrations, Soupir and Barnes (2006) reported that formalin concentrations lower than 1667 mg/L resulted in reduced walleye (Sander vitreus) egg survival during hatchery incubation. However, formalin tolerance varies by species (Rach et al, 1997) and the use of concentrations greater than 1000 mg/L for 15 min may reduce yellow perch egg survival (Abd El-Gawad et al, 2015).…”

“…1 al., 1982. Daily prophylactic treatments with formalin have proven to be effective at inhibiting fungal (water mold) growth (Soupir & Barnes, 2006;Rach et al, 1997). Fungal infestations can become particularly problematic towards the end of yellow perch Perca flavescens egg incubation (Hart et al, 2006).…”

Embryonic survival of Galaxias maculatus (Jenyns, 1842), under different prophylactic immersion bath

“…En el caso de la formalina, independiente de su toxicidad, este químico como funguicida evita la saprolegniosis obteniendo altos porcentajes de eclosión (Barnes et al, 2001(Barnes et al, , 2003Gieseker et al, 2006;Small & Chatakondi, 2006;Soupir & Barnes, 2006;Barnes & Soupir, 2007;Rasowo et al, 2007;Rowland et al, 2008;Rodriguez et al, 2011). En el caso del yodo hay evidencias de su capacidad como control de hongos (Pravecek & Barnes, 2003;Tendencia, 2003).…”