Comparison of
Manual Stripping and Pen Spawning for Production of Channel Catfish × Blue
Catfish Hybrids and Aquarium Spawning of Channel Catfish
R.A. Dunham, D.M. Lambert, B.J. Argue,
C. Ligeon, D.R. Yant, Z. Liu-2000
North American Journal of Aquaculture, 62(4): 249-259
Abstract:
We compare manual stripping to pen spawning for
production of hybrids of female channel catfish Ictalurus punctatus × male
blue catfish I. furcatus, as well as to aquarium spawning of channel
catfish. The ovulation rate for manually stripped females (91%) was not
significantly different from that of females spawned in aquaria with channel
catfish males (67%; P > 0.05); however, ovulation rate of manually
stripped females during week 10 (80%) was superior to that of females
spawned in pens (15%; P < 0.05) with blue catfish males. Female channel
catfish spawned in aquaria with male channel catfish produced more (P <
0.05) eggs per kilogram body weight (6,607) than manually stripped females
(4,587). Pen spawning of female channel catfish and male blue catfish also
produced significantly more (P < 0.05) eggs per kilogram (7,950) than
hand-stripping females (3,448) during week 10. Hatching rate (21%) and fry
per kilogram (1,065) of female body weight were higher (P < 0.05) for
channel catfish spawned with channel catfish in aquaria than for channel
catfish manually stripped and fertilized with blue catfish sperm (8% and 325
fry/kg). This difference in means was a result of spawning technique because
we have previously demonstrated that blue catfish and channel catfish sperm
fertilize channel catfish eggs at equivalent rates. Hatching rate (66%) was
also higher (P < 0.05) for pen-spawned hybrid embryos than for hybrid
embryos produced by manual stripping and artificial fertilization (21%).
However, fry per kilogram of female body weight was not different (P >
0.05) for manual stripping and pen spawning (851 and 821, respectively). The
results from both experiments indicate that the quantity and quality of eggs
and embryos obtained by manual stripping and artificial fertilization are
inferior to eggs and embryos produced naturally but with hormone injections.
Artificial fertilization procedures need to be improved. Hybrid fry produced
per kilogram of female body weight for manual stripping and pen spawning
were almost identical because of the low hatch rate for manually stripped
eggs and the low spawning rate for pen spawning. Therefore, neither
technique is better for commercial production of channel catfish × blue
catfish embryos; improved hatching rates for manual stripping or higher
ovulation rates for pen spawning would enhance production.
(Department of Fisheries and Allied Aquacultures,
Auburn University, Auburn, Alabama 36849, USA)
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