Research

Southern Flounder
Paralichthys lethostigma

Our objective is to establish the first southern flounder farms in the U.S. We have focused our efforts on husbandry techniques for rearing flounder to market size in closed, freshwater recirculating systems. Research projects have resulted in the development of breeding methods for all-females fingerling through production of gynogenetic diploids. Coupled with previous work on temperature-dependent sex determination, these flounder will reduce the time to market while promoting feed efficiency and economic performance.

Hybrid Striped Bass
Morone chrysops x M. saxatilis

Current research efforts are focused on the establishment of practical methods for effluent managment from hybrid striped bass production ponds. Production practices for hybrid striped bass require annual draining of the ponds to allow complete harvest of fish, to control external parasites, and for periodic pond renovation. Because of these practices, water use is high and effluents from fish ponds frequently leave the farms and enter public waters.

Studies have been conducted on the use of compensatory growth to improve feed efficiency and water quality. A multi-year study of zero-discharge production shows promising results that need to be validated in on-farm trials. Further studies to characterize effluents in receiving waters and to evaluate the effectiveness of Best Management Practices are currently being conducted and will continue for the next several years.

Yellow Perch
Perca flavescens

Previous work has been focused on reducing sexual growth dimorphism through the use of controlled photothermal regimes to inhibit sexual maturity. Photothermal conditions which inhibited maturation subsequently promted a more uniformly growing population.

Additional research evaluated the practice of cold-banking fingerlings. Cold-banking refers to the technique of holding fingerling fish at low temperature, high density and maintenance ration to arrest further growth. Banked fish can be held in reserve for off-season or staggered growout production, ensuring a steady supply of market-sized product.

NC Seagrant Project 03-AM-02: Accelerated Growth and Domestication of Yellow Perch

crab

Blue Crab
Callinectes sapidus

Blue crabs continue to support North Carolina’s most valuable commercial fishery. Significantly reduced landings of hard blue crabs have caused increased industry concern for the health of the resource and fishery and fueled interest in enhancement of the stock via aquaculture.

Current research evaluates the effect of multiple types and combinations of phyto- and zooplankton on survival and growth of larval blue crab through the first-crab stage. Our goal is to understand crab larval nutrition and simplify hatchery protocols by culturing just a few types of phyto- and zooplankton, instead of the current protocols of three to four of each. Data will be made available for the private sector in a hatchery manual.

Selected Publications:

Daniels HV,  Murashige R,  Shewmon LN.   2006.  Intensive Culture of  Southern Flounder in a Closed Recirculating System.  
          Proceedings of the 5th Conference on Reciculating Aquaculture.  In Press.

Morgan AJ,  Murashige R, Woolridge C, Luckenbach JA,  Watanabe WO,  Borski RJ, Daniels HV  2006.  Optimization  of UV dose and pressure shock for induction 
          of meiogynogenesis in southern flounder (Paralichthys lethostigma) using black sea bass (Centropristis  striata) sperm.  Aquaculture. In Press

Watanabe WO, Woolridge CA,  Daniels  HV.  2006.  Progress toward year-round spawning of  southern flounder broodstock by manipulation of photoperiod and 
          temperature.  Journal of the World Aquaculture Society.  In  Press.

Drake SL, Drake MA, Daniels HV, Yates MD. 2006. Sensory properties of wild and aquacultured southern flounder (Paralichthys lethostigma). Journal of Sensory 
          Studies 21(2):218-227.

Luckenbach JA, Early LW, Rowe AH, Borski RJ, Daniels HV, Godwin J. 2005. Aromatase cytochrome P450: Cloning, intron variation, and ontogeny of gene
           expression in southern flounder (Paralichthys lethostigma). Journal of Experimental Zoology Part A- Comparative Experimental Biology 303A(8):643-656.

Luckenbach JA, Godwin J, Daniels HV, Beasley JM, Sullivan CV, Borski RJ. 2004. Induction of diploid gynogenesis in southern flounder (Paralichthys lethostigma) 
          with homologous and heterologous sperm. Aquaculture 2371-4):499-516.

Luckenbach JA, Godwin J, Daniels HV, Borski RJ. 2003. Gonadal differentiation and effects of temperature on sex determination in southern flounder (Paralichthys 
          lethostigma). Aquaculture 216(1-4):315-327.

Luckenbach JA, Godwin J, Daniels HV, Borski RJ. 2002. Optimization of North American flounder culture: a controlled breeding scheme. 
          World Aquaculture. 33(1):40-45.

Middleton TF, Ferket PR, Boyd LC, Daniels HV, Gallagher ML. 2001. An evaluation of co-extruded poultry silage and culled jewel sweet potatoes as a feed 
          ingredient for hybrid Tilapia (Oreochromis niloticus x O. mossambicus). Aquaculture 198(3-4):269-280.

van Maaren CC, Daniels HV. 2001. Effects of temperature on egg hatch, larval growth and metamorphosis for hatchery-cultured southern flounder Paralichthys 
          lethostigma. Journal of Applied Aquaculture. 11(1-2):21-33.

Watanabe WO, Carroll PM, Daniels HV. 2001. Sustained, natural spawning of southern flounder Paralichthys lethostigma under an extended photothermal regime. 
          Journal of the World Aquaculture Society. 32(2):153-166.

Daniels HV, Gallagher ML. 2000. Effect of dietary protein level on growth and blood parameters in summer flounder Paralichthys dentatus. Journal of Applied 
          Aquaculture. 10(1):45-52.

Middleton TF, Ferket PR, Daniels HV, Boyd LC, Stikeleather LF, Hines RJ. 2000. The use of poultry mortalities as an alternative bait for the harvesting of blue crabs 
          Callinectes sapidus (Rathburn, 1885). Journal of Shellfish Research. 19(2):723-729.

van Maaren CC, Daniels HV. 2000. A practical guide to the morphological development of southern flounder Paralichthys lethostigma from hatch through
           metamorphosis. Journal of Applied Aquaculture. 10(2):1-10.

Daniels HV, Hodson RG. 1999. Weaning success of southern flounder juveniles: effect of changeover period and diet type on growth and survival. North 
           American Journal of Aquaculture. 61(1):47-50.

Harcke JE, Daniels HV. 1999. Acute toxicity of ammonia and nitrite to reciprocal cross hybrid striped bass Morone chrysops x M. saxatilis eggs and larvae. 
          Journal of the World Aquaculture Society. 30(4):496-500.

Daniels HV, Berlinsky DL, Hodson RG, Sullivan CV. 1996. Effects of stocking density, salinity, and light intensity on growth and survival of southern flounder 
          Paralichthys lethostigma larvae. Journal of the World Aquaculture Society 27(2):153-159.

Seagrant Publications:

Effluents from Hybrid Striped Bass Ponds: UNC-SG-BP-05-01

Improving Production of Hybrid Striped Bass Fingerlings Through Better Feeding Practices: UNC-SG-BP-00-02

Avoiding Ammonia and Nitrite Toxicity in Hybrid Striped Bass Hatcheries and Ponds: UNC-SG-BP-00-03

A Practical Hatchery Manual: Production of Flounder Fingerlings: UNC-SG-02-08
by Harry V. Daniels and Wade O. Watanabe

SRAC Publications:

Engle, C. J. Avery, H. Daniels, D. Heikes and G.  Lutz.  2004.  Guidelines for Developing Aquaculture Research Verification  Programs.  
          Southern Regional Aquaculture  Center Publication No. 5000. Stoneville, MS, USA.

Dunning,  R. and H.V. Daniels.  2002.  Economics of Hybrid Striped Bass Production  in Ponds.  Southern Regional Aquaculture Center 
          Publication no. 7169. Mississippi State University, Starkville, MS, USA.

Daniels, H.V.   2000.  Species Profile: Southern  flounder. Southern Regional Aquaculture Center Publication No. 726.  Southern Regional 
          Aquaculture Center,  Stoneville, MS, USA.