550 



Epifanio, C. E. 1973. 



A marine analogue to the husbandry of poultry on land. Proc. Del. Acad. 

 Sci., 9 p. 



A manuscript with the same title was received from Thomas Pickett, President 

 Delaware Acad. Sci. with the information that this was a draft, to be 

 published in vols. 3 & 4 of Del. Acad. Sci. in 1978. The date above must be 

 in error. The paper describes briefly the procedures used in oyster and 

 clam (Mercenaria mercenaria) culture at the University of Delaware. Brood 

 stock is collected in spring from wild stocks and held in flowing seawater 

 at 15°C. Cultured algae (Phaeodactylum triaornutum) are maintained in the 

 water at 10 4 cells/ml. After 5 to 6 weeks conditioning bivalves can be 

 spawned at any time, by transferring rapidly to 2 8°C seawater. This is 

 often sufficient to stimulate release of gametes, but usually a male is 

 sacrificed and some sperm introduced into the water as a further stimulus. 

 Veliger larvae develop about 24 hrs after fertilization. They are fed with 

 cultured Isochrysis galbana and Monochrysis lutheri . Clams complete larval 

 development in an average of 10 days. Metamorphosed larvae set on sides 

 and bottom of growing tanks. They detach later. Culture to market size 

 has not yet been completed. Culture is in recirculating water in which 

 conditions are highly controlled. Nitrification is accomplished in a 

 submerged biological filter, ultraviolet radiation controls bacteria, and 

 an activated carbon filter adsorbs dissolved organic compounds. Alkalinity 

 and temp are controlled. Detailed records of conditions are maintained. 

 Algal cultures produce up to 1013 cells/day. Fastest growing clams have 

 grown to better than 30% of market size in 9 months. It is expected that 

 market size will be reached in about 2 yrs . There do not appear to be any 

 behavioral barriers to growing large numbers of clams in relatively small 

 space. It appears possible to recycle nitrogenous excreta to greenhouse 

 culture of algae. Food value of algal species varies greatly. More 

 research is needed. Details are given more completely in published papers 

 abstracted elsewhere in this bibliography. - J.L.M. 



551 



Epifanio, Charles E. 1976. 



Culture of bivalve mollusks in recirculating systems: Nutritional require- 

 ments. In Proc. 1st Internatl. Conf . Aquacult. Nutrition, October, 1975. 

 Sea Grant Coll. Program, Univ. Del. and U.S. /Japan Aquaculture Panel/ p. 

 173-194. 



This review paper concludes that, although interest in nutrition of juvenile 

 and adult bivalves has increased considerably, level of knowledge is low 

 compared with that for decapods or fishes. No nutritionally adequate, 

 formulated diet for bivalves has yet been developed. Research has been 

 limited largely to determining which commonly cultured algal species are 

 good foods, and to studying energetic efficiences of bivalves fed algal 

 diets. The amount of control that can be exerted over chemical composition 

 of algae is small compared to that possible with formulated diets, but when 

 formulated diets are not available, it is reasonable to continue 

 experimenting with modified algae. Reasons for failure of formulated diets 

 to support normal growth of bivalves may be as much physical as biochemical. 

 Different techniques should be developed for producing particles of 

 appropriate size, texture, and other characteristics, as well as chemical 

 composition. More detailed analyses of algal species which are good foods 

 also should be done. Major obstacle to development of commercially viable 

 intensive bivalve culture systems is continuing inability to produce massive 

 algal cultures at reasonable cost. Solution of problems associated with 

 mass culture of algae is needed, as well as improved information on 

 nutritional requirements of bivalves. Papers cited with reference to 

 Mercenaria (Venus) mercenaria are abstracted elsewhere in this bibliography. 

 - J.L.M. 



154 



