Efficacy of hydrogen peroxide to control Saprolegniasis on cool-

and warmwater fish eggs

Hydrogen peroxide INAD 10-023

(Perox-AidTM)

Egg Efficacy Trial Participants

• Mark Drobish – Gavins Point NFH

• Lynn Lee – UMESC

• Andy Moore – Rathbun Research

• Clark Moen – Blue Dog SFH

• Tom Harder – Max McGraw

• Dennis Smith – Dundee SFH

• Jerry Hamilton – Blind Pony SFH

INAD #10-023

• Study CAP-00-FUNGUS– submitted to CVM 03 March 2000– Twenty-nine participating facilities

• Study CAP-00-PARASITES– submitted to CVM 18 April 2000– Twenty-one participating facilities

• Study CAP-00-BACTERIA– submitted to CVM 18 April 2000– Twenty-three participating facilities

INAD #10-023 Participant Locations

UMESC

Western Chemicals

Eka Chemicals, Inc

Protocol Methods

Identify Disease

“Control”

Station History

“Prevention”

Select therapy and treat• concentration• duration• frequency• repetition

Chemical Inventory

Monitor / Record Mortality

Adverse Reactions

Monitor / Record Mortality

Controls?

Hydrogen peroxide therapy - Fish

• Duration: 30 or 60 min• Concentration

– 50, 75, or 100 mg/L for 60 min – 100 or 150 mg/L for 30 min

• Repetition/Interval: once daily on consecutive or alternate days for up to 10 treatments.

Hydrogen peroxide therapy - Eggs

• Duration: 15 min• Concentration: 500 or 750 mg/L

– minimum incubator concentration is 500 mg/L for 15 min

• Repetition/Interval: Once daily on consecutive or alternate days through hatch

Egg Efficacy Trials

• Seven egg efficacy trials conducted– Blind Pony SFH, Jerry Hamilton, paddlefish– Blue Dog SFH, Clark Moen, walleye– Dundee SFH, Dennis Smith, smallmouth bass– Gavins Point NFH, Mark Drobish, walleye– Max McGraw, Tom Harder, walleye– Rathbun SFH, Alan Moore, channel catfish– UMESC, Lynn Lee, walleye

• Fungus identified in three trials

Saprolegnia parasitica

Zoospores in zoosporangium

(blue arrow)

Gemmae (red arrow)

Photo credit: Steve Carpenter, Ph.D., Abbey Lane Labs.

Blind Pony SFH - paddlefish

• Temperature 15 - 16°C• Four trials - one or two females per trial

– 500, 750, or 1000 mg/L– % hatch ranged from 14 - 56% (of fertile eggs)– 2 - 4 consecutive treatments; fungus in all treated jars– noted cessation of egg development after hydrogen

peroxide treatment– withholding treatments until 2 d post fertilization resulted in

basically no hatch– compared rolling w/o treatment to hydrogen peroxide

treatment w/o rolling• rolled eggs - 60% hatch treated eggs 24% hatch

Blind Pony - paddlefishSaprolegnia ferax

Oogonium with oospores showing cell wall pitting.

Oogonia and gemmae from sterile house fly culture.

Photo credit: Steve Carpenter, Ph.D., Abbey Lane Labs.

Max McGraw - walleye

0102030405060708090

100

Per

cen

t h

atch

(%

)

Control 500

Treatment

rep 1

rep 2

rep 3

~ 1 million eggs total

x = 72% x = 68%

Blue Dog SFH - walleye

0

20

40

60

80

100

% e

yed

Form

- 1

Form

- 2

Form

- 3

H202

- 1

H2O2

- 2

H2O2

- 3Lot 5

Lot 4

Lot 3

~1.5 million eggs total

Gavins Point NFH - walleye

~3.1 million eggs total

58.365.5

75.5

0

20

40

60

80

100

Mea

n P

erce

nt

Hat

ch

Control

500 mg/L

750 mg/L

Gavins Point NFH - walleye

Control 500 mg/L 750 mg/L

Photo credit: Mark Drobish, Gavins Point NFH

UMESC - walleye

48.653.1* 49.7

65.9

78.1*70.0

0102030405060708090

100

Mea

n %

Hat

ch

Green Eyed

Control

500 mg/L

750 mg/L

~2.7 million eggs total

UMESC - Walleye

Overflow

Overflow

Plexiglass dividers

Perox-Aid stock solutions

Stock solution delivery lines

Headbox

Airstone Egg Jar

Pump

Hydrogen peroxide stock solutions

Dundee SFH - smallmouth bass eggs

01020

3040

5060

7080

90100

Per

cen

t h

atch

(%

)

Control 300 500 750

Treatment

rep 1

rep 2

rep 3

~ 2500 eggs per jar

~30,000 eggs total

Dundee SFH - smallmouth bass eggs

0

20

40

60

80

100

120

140

fung

used

egg

s

day 1

day 2

Number of fungused eggs removed during incubation.

Dundee SFH - smallmouth bass fry

0

10

20

30

40

50

60

70

80

90

100

Pe

rce

nt

su

rviv

al (

%)

Control 300 500 750

Treatment

rep 1

rep 2

rep 3

~ 2500 fry per tank

~30,000 fry total

Rathbun SFH - channel catfish eggs

0

1000

20003000

4000

5000

6000

70008000

9000

Nu

mb

er

of

fry

Rathbun SFH - channel catfish control eggs

Photo credit: Andy Moore, Rathbun SFH

Rathbun SFH - channel catfish treated eggs

Photo credit: Andy Moore, Rathbun SFH

Conclusions

• A hydrogen peroxide treatment regimen of 500 mg/L administered for 15 min on consecutive days from incubation to hatch is effective in controlling fungus on walleye and channel catfish eggs.

• Hydrogen peroxide virtually eliminated fungal growth in both walleye and channel catfish eggs and increased the probability of walleye hatch in two of three controlled trials.