Meeting Abstract
The vinegaroon (Mastigoproctus giganteus) is a nocturnal desert-dwelling arachnid known for spraying acetic acid from its tail at its attackers. For our study of vinegaroon energetics, we used closed-system respirometry to quantify their postfeeding metabolic profile and specific dynamic action (SDA), the total cost of meal digestion. Following a cricket meal, metabolic rates of vinegaroons at 30°C rose sharply to peak within 12 hours at twice the prefeeding standard metabolic rates (SMR). Metabolic rates then declined, retuning to SMR within 30 hours after feeding. For cricket meals approximately 5% of vinegaroon body mass, SDA averaged 60.2 J, equivalent to 2.85% of meal energy. Across meal sizes (3.5-13% of body mass), SDA increased as a function of meal mass, nearly tripling with a doubling of meal energy. Independent of meal size and energy, the SDA of vinegaroons is similar to that experienced by various species of tarantulas and scorpions, as well as being similar to the SDA of other species of invertebrates.
