catfish wars - university of california,...
TRANSCRIPT
ANS 18ANS 18 -- CATFISH vs BASACATFISH vs BASA 1818
“David” =Vietnamese cageculture of Asian
catfish
“Goliath” =U.S. pondculture of
catfish
Catfish WarsCatfish Wars
ProductionCycle
7-8 yr old3-yr
Caviarmarket
Females(sacrificed)
Males
Meatmarket(live orwhole torestaurant)
Cobia Larval Rearing = 28 – 30oC
• Hatching – larvae = 3.5 mm in length
• 3 – 7 dph = Enriched rotifers
• 5 – 7 dph = Brine shrimp nauplii
• 7 – 15 dph = Enriched 2nd – 3rd instar meta nauplii
• 15 – 25 dph = weaned to formulated feeds
200 – 350 μm
1.5 mm
• Fingerlings = 1 gram 75 dph = 30 grams
*
* Although the timing varies, the sequence of feed types istypical for marine fish larval culture
Green-waterTechnique
80%mortality
mortality nil
Feeding - Polytrophismresidual fromvegetation thatgrows during thedry period - baseof a detritus foodweb - typicalharvests of ~ 600kg/ha/yr (withoptimumconditionsharvests can beup to 3 mt/ha/yr).
Plant materialMicrobially
enriched detritus
ZooplanktonSubstrate
Invertebrates
> 25oC
BURROW