Yellow Perch Broodstock

Geoff WallatOhio State University

Ohio Center for Aquaculture Development

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

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

Broodstock sorting

• Spawning temperatures of around 12 C in late March in southern Ohio

• Broodstock are sorted in early March

Sexual Differentiation• Males are generally smaller than females and slower growing – Sexual

dimorphism• In late Winter/Spring, females abdomen swollen; ovopore swollen and extended

Sex Determination

Female

Male

Ripe Female – Strip spawning

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

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

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

Broodstock Nutrition Study Results

Diet Type Egg Ribbons produced Surviving Egg Ribbons Mean Number of Fry

Low Fat (8%) 7 5 17,244Medium Fat (10%) 8 5 3,453High Fat (16%) 9 7 8,354Minnows 12 6 10,130

• 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

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

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

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

Growth of Different Strains at 22 oC – Combined 2004 and 2005 data

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Broodstock Summary

• Use a good, reliable source of broodstock

• Conditioning period (cold period)

• Nutritional component still needs more work