U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Harry K. Dupree Stuttgart National Aquaculture Research Cntr: Stuttgart, AR
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Southeast Area Stuttgart, Arkansas Harry K. Dupree Stuttgart National Aquaculture Research Cntr Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- IACUC Summary

Title:   Author  item
                                            Straus, David

                                                         - *Dave*item
                                            Mitchell, Andrewitem
                                            Carter, Rayitem
                                            McEntire, Matthew

                                                         - *Matt*item
                                            Radomski, Andrewitem
                                            STEEBY, JAMES - MSU-WARMWATER AQUACULTURE
  Submitted to: Aquatic Animal Drug Approval Partnership (AADAP)
                                    Publication Type: Other
                                    Publication Acceptance Date: 10/24/2008
                                    Publication  Date: 10/31/2008
                                    Citation: Straus, D.L., Mitchell, A.J., Carter, R.R., Mcentire, M.E., Radomski, A.A., Steeby, J.A. 2008. The safety and effectiveness of CuSO4 to control fungus on intact egg masses in channel catfish hatcheries. Aquatic Animal Drug Approval Partnership (AADAP). 4(3):7.Interpretive Summary:
                                Technical Abstract: Copper sulfate (CuSO4) is widely used by the catfish industry as an economical treatment to control fungus (Saprolegnia spp.) on channel catfish eggs.  This is an overview of our effectiveness and safety studies for the proposed indication ‘to control egg mortality associated with Saprolegniasis infecting channel catfish eggs’.

Channel catfish were spawned on-site and spawns were moved to the hatching lab within 24 - 48 hrs.  Similar portions of a single spawn were placed into mesh baskets of individual compartments of a customized hatching trough and acclimated for 1 hr in 23.5 degrees C well water.  Egg counts on smaller samples were also determined for each spawn to estimate number of eggs in each compartment.  The Effectiveness range-finding study consisted of 5 CuSO4 concentrations (2.5, 5, 10, 20, and 40 ppm) and an untreated control.  Eggs were treated daily until the embryos developed eyes.  Chemistry of the well water was pH 7.5, 220 ppm alkalinity, and 90 ppm hardness.  When hatching was complete for all viable eggs, fry were siphoned into individual jars containing 70% ethanol and counted within a few days to determine the percent of fry that hatched in each treatment.  Fungus was severe in the untreated controls (2% survival) and the most effective treatment of 10 ppm CuSO4 controlled fungus (63% survival).  Very little fungus was present in treatments receiving 10 ppm CuSO4 or higher except in 1 replication (1 spawn) that had numerous unfertilized eggs.  Two dose-confirmation studies have been completed to verify the optimum dose of 10 ppm both in the lab and at a commercial hatchery.

The Target Animal Safety study was designed to access the safety of CuSO4 to channel catfish eggs when treated at the therapeutic rate (10 ppm) determined above, and also at 30 and 50 ppm CuSO4.  Channel catfish were obtained as described above and eggs were treated daily until the embryos developed eyes; exchange rate of the 26 degrees C water was 90 minutes (3X the normal rate) during treatments.  When hatching was complete, the percent hatch in each treatment was determined.  Some fungus developed in the controls at this temperature and mean percent hatch was 40.8%.  The percent hatch of the 10, 30, and 50 ppm CuSO4 was 80.1, 64.2 and 80.2%, respectively.  The difference between the 10 and 30 ppm CuSO4 treatments was statistically significant, while the difference was not significant between the 10 and 50 ppm CuSO4 treatments.  The lower hatch-rate of the 30 ppm treatment is attributed to the random sampling within the original egg masses and the range of hatching rates that are common in the industry.  A separate experiment looked at the hatching success when eggs were treated daily until the embryos developed eyes with 100 ppm CuSO4.  The water temperature was 24 degrees C and the exchange rate during the treatment was 30 minutes.  The individual percent hatch of each replication was 62.7, 94.9, 59.7 and 64.8%.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov