Food-Chains and the Food Cycle in Hawaiian Fish Ponds.–Part I. The Food and Feeding Habits of Mullet (Mugil Cephalus), Milkfish (Chanos Chanos), and the Ten-Pounder (Elops Machnata)

Abstract

Abstract The food and feeding habits of the three most important market fish in Hawaiian ponds (Mugil cephalus, Chanos chanos, and Elops machnata) were analyzed to ascertain the position of these fish in the food-chains and the food cycle occurring within the ponds. Mullet (M. cephalus) subsist primarily on littoral diatoms and blue-green algae, the presence of a unique pharyngeal filtering device prohibiting them from swallowing larger forms. No variation in food because of season or size of fish was found. Milkfish (C. chanos) are also herbivores; juveniles consume unicellular and other minute algae while larger fish take an increasing amount of larger filamentous algae. Competition for food between mullet and milkfish is greater than hitherto supposed and cannot be diminished under present operational procedures. An increased food supply for both species probably could be achieved by the application of inorganic fertilizers together with the construction of additional shallow areas in the ponds. Ten-po...