Meeting Abstract

P1.90  Monday, Jan. 4  Meal type effects on lizard specific dynamic action SMITH, M.E.*; DUREAU, J.; DUKE, J.T.; SECOR, S.M.; University of Alabama; University of Alabama; University of Alabama; University of Alabama mesmith10@crimson.ua.edu

We examined the effects of meal type on the specific dynamic action (SDA) of the following four lizards; curly-tailed lizard (Leiocephalus carinatus; Leiocephalidae), bearded dragon (Pogona vitticeps, Agamidae), golden gecko (Gekko auratus; Gekkonidae), and ocellated skink (Chalcides ocellatus, Scincidae). We hypothesized that hard-bodied prey would generate a greater SDA than soft-bodied food, and that SDA would increase with meal energy content. Lizards were fed hard-bodied crickets, mealworm beetles, and either mealworms or superworms, and soft-bodied waxworms, butterworms, and silkworms. Meals equaled in mass to 5% of lizard mass and SDA measurements were conducted using closed-system respirometry at 30C. All meals generated for each lizard significant increases in oxygen consumption (VO₂) that remained elevated for 2 (silkworm meal) to 8 (superworm meal) days. The factorial scope of peak postprandial VO₂ (peak VO₂/SMR) was significantly greater (by an average of 38%) for hard-bodied prey compared to soft-bodied prey for each species. SDA, calculated from the extra oxygen consumed above SMR, averaged 88% greater for hard-bodied meals than soft-bodied meals for the four lizards. Silkworms required the least amount of energy to digestion, whereas superworms and beetles required the most. SDA coefficient, SDA as a percentage of meal energy, varied among meals (9.9% for butterworms to 28.6% for crickets) and was greater for hard-bodied (25.7%) than soft-bodied (13.4%) meals for each lizard. SDA increases with meal energy for Leiocephalus, Pogona, and Chalcides. The lack of an increase for Gekko was due to their modest SDA for the high-energy butterworm meals.