Meeting Abstract

P1.108  Friday, Jan. 4  Postprandial metabolic response and specific dynamic action of scorpions BELANICH, J.R.*; SECOR, S.M.; University of Alabama, Tuscaloosa; University of Alabama, Tuscaloosa jrbelanich@crimson.ua.edu

A mandatory physiological response to meal digestion and assimilation is an increase in metabolic rate; the accumulative cost of which is referred to as specific dynamic action (SDA). Whereas SDA has been examined for a wide spectrum of invertebrate and vertebrate groups, there has been relatively little attention paid to the postprandial metabolic responses of arachnids. In this study we characterize the postprandial metabolic profile of six scorpion species, (Centruroides sculpturatus, Hadrurus arizonensis, Heterometrus longimanus, Hottentota trilineatus, Opistophthalmus whalbergi, and Pandinus imperator) representing three families following their consumption of crickets. Body mass of scorpions ranged 0.8 g for C. sculpturatus to 17.5 for P. imperator and meal sizes ranged from 4.6 to 19.5% of scorpion body mass. All scorpion species responded with a rapid increase in metabolic rate that peaked at six hours after feeding before declining and returning to prefeeding rates within three days. Postprandial metabolic peaks ranged from 1.8 to 5.3-fold of SMR and did not necessarily correlate with relative meal size. SDA ranged from 15 – 297 J and was largely determined in magnitude by body mass, however mass specific SDA was significantly greater for the smaller species. The SDA coefficient (percentage of meal energy equivalent to SDA) ranged from 2.4 for O. whalbergi to 11.4 for C. sculpturatus.