Regressions for Estimating Gastropod Biomass with Multiple Shell Metrics

Abstract

1Department of Biological Science, Florida International University, 3000 NE 151st Street, North Miami, Florida 33181, U.S.A. 2Ocean Associates, Inc., 501 W. Ocean Blvd, Suite 4200, Long Beach, California 90802, U.S.A. 3Department of Biology, Columbus State University, Columbus, Georgia 31907, U.S.A. *Corresponding author: aobaza@yahoo.com power and provide more accurate biomass estimates for snails because they exhibit a diversity of shapes. Comparisons among possible regression models may reveal that different metrics or combinations of metrics are better predictors of a particular mass measure for a given group (e.g., AFDM vs. wet mass). In this study, we consider three common, structurally diverse freshwater snail genera Planorbella, Pomacea and Haitia to examine the utility of using multiple length measures to predict multiple soft-tissue mass measures. Planorbella (Planorbidae) are pulmonate snails with planispiral shells that grow sinistrally (left handed). Haitia (Physidae) are small pulmonates with a sinistrally growing conispiral shell. Pomacea (Ampulariidae) are large caenogastropods that have globose, conispiral shells that are generally dextral (right handed) with