Richard F. Ford

Laboratory culture of juvenile stages of the California spiny lobster Panulirus interruptus (Randall) at elevated temperatures

Abstract Puerulus stage individuals of Panulirus interruptus from coastal waters off San Diego, California, were cultured through juvenile stages at constant temperatures of 22 and 28 °C in closed-system aquaria. In these laboratory trials juveniles exhibited average growth rates of approx. 3.3 mm increase in carapace length ( CL ) per month at 22 °C, and approximately 4.5 mm per month at 28 °C. These rates, respectively, are about two and three times greater than estimated growth rates of juveniles in nature at ambient southern California ocean temperatures. Accelerated growth at elevated temperatures was associated with increased moulting rates (reduced intermoult periods) rather than with greater increments per moult. Aquaculture of P. interruptus juveniles at elevated temperatures appears feasible, but currently is dependent on locating areas where puerulus or post-puerulus stages can be obtained in quantity without adversely affecting natural populations.

A recirculating culture system for larvae of the American lobster, Homarus americanus

Abstract A recirculating culture system is described, suitable for mass rearing of larvae of the American lobster ( Homarus americanus ) and other larval forms.

Early development, growth and survival of the yellow crab Cancer anthonyi Rathbun (Decapoda, Brachyura) in the laboratory☆

Abstract Larvae of the yellow crab, Cancer anthonyi Rathbun, were reared through five zoeal stages and one megalops stage in the laboratory. Total larval development times were 33 and 45 days at 22°C and 18°C, respectively. Survival rates to the first crab instar, for larvae reared in recirculating systems on a diet of Artemia nauplii, were 26% at 22°C and 17% at 18°C. Although no larvae reared in glass containers at 22°C survived past the first zoeal stage, 11% of those in similar containers at 18°C reached the first crab instar. Bacterial infections were associated with most observed mortalities. Antibiotics failed to increase the survival rates of larvae reared in glass containers. Juvenile crabs were reared in individual containers and in communal aquaria through 14 crab instars. Although instar durations were shorter at 22°C than at 18°C, mean carapace widths were significantly greater at the lower temperature. Crabs in communal aquaria at 22°C were larger than corresponding crabs at the same temperature in individual containers. Crabs reared in aquaria at 22°C reached the twelfth instar with a mean size of 90.3 mm, 195 days after hatching. Sexually mature thirteenth stage laboratory-reared crabs were mated and their offspring were reared through the ninth crab stage.

An automatic feeding device and the use of live and frozen Artemia for culturing larval stages of the American lobster, Homarus americanus

Abstract A simple and inexpensive automatic feeding device is described, suitable for dispensing a variety of food items to larval stages of Homarus americanus or other larval forms. The device consists of a row of food cups which are periodically tipped and emptied into the culture container by a revolving tripping bar driven by a clock motor. The feeding interval, as well as the amount and type of food, can be varied as required. A description also is given of the use and relative effectiveness of frozen and live adult brine shrimp (Artemia salina) as food for Homarus larvae.