Linda Benedict, McClain, W. Ray | 11/15/2011 10:12:01 PM
A system to test various aspects of crawfish biology and culture has recently been completed at the South Unit of the Rice Research Station in Crowley.
A series of 12 fiberglass tanks (each 12 feet in diameter and 5 feet high) were set up to provide many of the amenities of earthen crawfish aquaculture ponds, albeit with the ability to exercise greater control over some of the key variables affecting growth and production.
The outdoor tanks contain soil, planted crops of rice (forage for crawfish), supplemental aeration, and individual water inlets and outlets. When stocked with known numbers and sizes of crawfish, the tanks will serve as semi-natural mesocosms conducive to research that would be difficult or impossible to conduct in ponds.
The first research trial to be conducted in these mesocosms is under way. The objectives of this research are to obtain more comprehensive data on the relationship of crawfish growth to water temperature and to ascertain cumulative degree-day (DD) requirements for crawfish. Like the DD-50 model for rice, which uses cumulative degree-days to determine time to various growth stages in rice, the data generated from this study will relate cumulative degree-days to growth of crawfish and more precisely the degree-day requirements necessary for hatchlings to reach the minimum market size of 15 grams or 30 count per pound.
This information will be useful for crawfish aquaculture managers that want to more accurately predict time to harvest based on peak periods of young-of-the-year recruitment. This information could also be used as a diagnostic tool for assessing reproductive trends and population dynamics.
(This article was published in the fall 2011 issue of Louisiana Agriculture magazine.)
The LSU AgCenter and the LSU College of Agriculture