Yellow Perch Broodstock

1. Yellow Perch Broodstock Geoff Wallat Ohio State University Ohio Center for Aquaculture Development

2. Perch 101 • Spawn once a year: Late March in So. Ohio • Eggs produced in ribbon structure –requires unique procedures for incubation and hatching • Fry (juveniles) need small live organisms for first few weeks’ feeding – 6 week culture period in open ponds. • Juveniles trained to accept formulated diets – “Feed training” or “Feed Trained Fingerlings” • Open ponds – 2 seasons (18 months) to food fish market size of > 8” from fry size

3. Broodstock conditioning • Perch broodstock require a cold period of around 140 days, at or below 10 o C • We use 1 m 3 culture cages in open ponds and maintenance feeding with pelleted trout diet • Broodstock conditioning research is an area of research need

4. Broodstock sorting • Spawning temperatures of around 12 C in late March in southern Ohio • Broodstock are sorted in early March

5. Sexual Differentiation • Males are generally smaller than females and slower growing – Sexual dimorphism • In late Winter/Spring, females abdomen swollen; ovopore swollen and extended

6. Sex Determination Female Male

7. Ripe Female – Strip spawning

8. Broodstock Nutrition • Important component • We typically feed a prepared diet at maintenance rations (1% BW) once or twice a week • Have found some difficulties with egg quality in pellet-raised fish • Supplementing with live feeds may be needed

9. Broodstock Nutrition Study 2004-2005 • Our study had diets formulated to vary the amount of total fat • 4 treatments • 3 prepared diets, held at 36% protein • Low Fat 8% • Medium Fat 12% • High Fat 16% • Control diet was minnows, fed twice a week to satiation

10. Broodstock Nutrition Study 2004-2005 • 3 replications per treatment • 20 females and 50 males, per treatment • Split to 3 tanks in equal proportions • Fed from December 2004 to March 2005

11. Broodstock Nutrition Study Results • Several of the Egg Ribbons did not survive to full term • Low spawning rate ( < 50 % for most treatments) • More work is needed on proper perch broodstock nutrition

12. Selection of Broodstock • Need healthy, good sized broodstock • Minimum 2 years old, 3 is better • Size is about 10 to 14 inches at that age • Geographical strain differences for growth may also be a factor • Our Genetics Improvement program has noticed some initial differences in performance

13. Progress of the Program • Eight strains were obtained from ME, NY, PA, NC, OH, NE, MI, and WI • 74 families have been achieved by crossing • Approximately 3-5 families or groups of offspring were obtained from each strain of broodfish (except MI and ME) • F1 broodstock have been selected • Best strains have been identified

14. Strain Evaluation (pure) • Study 1: Growth and GGE of Different Strains at 22 O C –Tank Culture • Study 2: Growth and of different strains at ambient temperature (fry to harvest size) • Study 3: Quantifying genetic variation within and among broodstock groups

15. Growth of Different Strains at 22 oC – Combined 2004 and 2005 data a a a a b c

16. Growth of strains at ambient temperature(Fry to harvest size) a Nursery + Feeding training Experiment period b c z z y

17. GGE of strains at ambient temperature(Fry to harvest size) a b b

18. Broodstock Summary • Use a good, reliable source of broodstock • Conditioning period (cold period) • Nutritional component still needs more work