|ZHENGZHONG, ZHANG - UAPB
|THOMFORDE, HUGH - UAPB
|GOODWIN, ANDREW - UAPB
Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2003
Publication Date: 1/1/2004
Citation: Zhengzhong, Z., Pfeiffer, T.J., Thomforde, H., Goodwin, A. 2004. Effects of temperature and size on ammonia excretion by fasted golden shiners (Notemigonus crysoleucas). North American Journal of Aquaculture. 66:15-23.
Interpretive Summary: Golden shiner is the major baitfish transported and sold in the United States. To allow more fish per truck load to be transported, the transport system for these fish need to be improved. Determination of the ammonia excretion rates of golden shiners is critical for improving the live transport systems since the increase of ammonia in the delivery tanks during transport limits the amount or number of fish that can safely be transported without any mortality. To simulate live hauling conditions, ammonia excretion rates of golden shiners fasted and acclimated for 2 days at water temperatures of 15, 20 and 25 C were conducted for a 24 hour period. The experiment was repeated four times using different size and batches of shiners. Results indicated no significant differences of hourly excretion rates (HERs) between batches of the same size golden shiners. However, as fish size increased (from 2.7 g to 3.6 g) HERs decreased and as water temperature increased (from 15, 20 to 25 C), HERs significantly increased. With the ammonia excretion data obtained, the most feasible method for increasing the transport load of golden shiners is to recirculate the water in the delivery tanks through a zeolite filter to prevent the ammonia concentration in the tanks from building up to harmful levels during transport.
Technical Abstract: Golden shiners are the major species of the baitfish transported and sold in the United States. Basic data of ammonia excretion rates of golden shiners is critical for live transport practice and rational design of improved live transport systems. To simulate live hauling conditions, experiments of ammonia excretion rates of golden shiners fasted and acclimated for 2 days at water temperatures of 15, 20 and 25 C were conducted for 24 hr in three recirculating systems simultaneously by the stopping water flow method. The experiment was repeated four times using different size and batches of shiners. Results indicated no significant differences of hourly excretion rates (HERs) between two batches but same size golden shiners, however, with fish unit size increasing from 2.7 g to 3.6 g, and temperature increasing from 15, 20 to 25 C, HERs significantly decreased and increased, respectively. Temperature was a covariate to the fish size affecting HERs. Average hourly ammonia excretion rates (HER) at 15, 20 and 25 C ranged from 2.9 to 7.4, 5.2 to 11.2, and 6.2 to 15.0 NH3-N/kg fish/hr, respectively. The maximum value of average daily ammonia excretion rates at each of the three temperatures was applied to calculate the size of floating media biofilter (FMBF) and zeolite filter needed for one hauling vat (378.5 L water, 63.5 kg fish) transported for 24 hrs. Considering the limitations of temperature, salinity and the operational feasibility, zeolite filter is more promising than a FMBF for live fish transport.