ISSN:
1749-7345
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Maximum handling sizes, prey size and species preferences, and ad libitum consumption rates were determined for three size classes of redear sunfish Lepomis microlophus feeding on Physa gyrina and Helisoma trivolvis, two common aquaculture-pond snails which serve as intermediate hosts for fish parasites. Maximum handling-size experiments indicated that redear sunfish as small as 14-cm total length were capable of consuming all sizes of Physa typically observed in ponds, whereas only redear sunfish of at least 32-cm total length are capable of consuming all commonly observed sizes of pond-dwelling Helisoma. When presented with a range of sizes of both snail species, redear sunfish consumed higher proportions of smaller- and medium-sized snails; the largest snails offered were uneaten or consumed in relatively small quantities. Multiple linear regression was applied to consumption data to develop a simple model for predicting mean daily ad libitum consumption rate (g/g per d) for redear sunfish feeding on snails with temperature (20–27 C) and fish total length (9–24 cm) as independent variables. Our findings will facilitate prediction of numbers of redear sunfish of a given size required to control populations of Physa and Helisoma in ponds. Such predictions will enable pond owners to quickly evaluate whether stocking redear sunfish as a control agent for undesirable snail populations will be economically and logistically feasible. Findings also indicate potential limitations in the use of redear sunfish to control populations of Helisoma due to the inability of redear sunfish as large as 24-cm total length to consume the largest 30–40% of Helisoma commonly observed in ponds and to the expense of stocking larger fish (32-cm total length) capable of consuming all sizes of Helisoma.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1749-7345.2003.tb00075.x
