Aquaculture

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Unformatted text preview: ponds a r e . 4 to . 5 ha (hec ta r es) {hec ta r e = 10000 sq m = 2. 47 a c r es); r a nge fr om . 4 to 40 ha ; depths r a nge fr om . 9 to 1. 8 m in South US & 1. 8 to 3. 0 m in N or th to a void winter kill. 3) Ra ising Ca tfish: most ' fa r mer s' pur c ha se finger lings (13 to 15 c m) a nd gr ow to a typic a l ma r ket weight of 1 lb in 1. 5 to 2 yr s (sma ll ma r ket for 4 lb c a tfish). Stoc king r a tes va r y fr om 2200 to 6600 finger lings per ha depending on food a nd oxygen. c ) F eeding Ca tfish 1) Diet - c a tfish r ely on supplementa r y feeding r a ther tha n living off a va ila ble food of the pond; typic a l diet ha s min 32% pr otein (with a t lea st ha lf being a nima l pr otein), fa t between 4 a nd 8%, fiber between 8 a nd 20%, min of 8% fish mea l. 2) F eeding Level - a t wa ter temp of 16 to 21 C feed a t 2% of tota l pond weight; a t wa ter temp of 21 to 32C feed a t 3% of tota l pond weight; over 32 C feed a t 1. 5% of tota l pond weight or less. d) B r oodstoc k a nd Spa wning 1) Sexing - c a tfish, like livestoc k, a r e usua lly r ea r ed in sa me sex gr oups; ma les ha ve da r ker c olor , shor ter wider hea d tha n fema les; genita l opening in fema les is slitlike a nd is tubula r in ma les; a s spa wning time a ppr oa c hes ma les get da r ker under the ja w a nd body, genita l pa pilla e pr otr ude; the vent of the fema le loosens, swells a...
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This document was uploaded on 01/24/2014.

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