Temperature and water relations of the giant whip scorpion, Mastigoproctus giganteus (Lucas) (Arachnida, Uropygi: Thelyphonidae).

摘要

Experiments were conducted to assess the effects of ambient temperature (TA) and relative humidity (RH) on the duration of embryonic development, upper (ULT50) and lower (LLT50) lethal temperatures, critical thermal minimum (CTMmin) and maximum (CTMmax) temperatures, survival, and preferred temperature in the giant whip scorpion, Mastigoproctus giganteus. No embryos completed development under xeric conditions (12% RH), regardless of TA. Embryonic development required 42-47 days at 15 degrees C, compared with 37-39 days at 22 degrees C and 27-32 days at 29 degrees C, at RHs of 40 and 75%. ULT50 values ranged from 35.2-38.5 degrees C and 38.3-41.1 degrees C, for nymphal stages under xeric (12% RH) and mesic (75%) conditions, respectively, and 40.2-42.6 degrees C for adults. LLT50 values ranged from 3.5-4.7 degrees C and 3.3-4.5 degrees C for nymphs under xeric and mesic conditions, and 3.3 degrees C for adults. CTMmin values ranged from 4.72-7.54 degrees C for nymphal and adult stages depending on acclimation temperature (10 or 30 degrees C), while CTMmax values ranged from 37.3-41.9 degrees C. Under xeric and mesic conditions, survival capacity was greatest between 25 and 30 degrees C for nymphs and adults. Less than 10% of whip scorpions survived at 5 degrees C, regardless of RH. No animals survived when exposed to a TA of 45 degrees C. Survival was low at a TA of 40 degrees C (5% for nymphs, 12-15% for adult males and females) under xeric conditions; under mesic conditions: 9% (nymphs); 31-36% (adult males and females). Seventy-six percent of nymphs chose a temperature range of 23-28.9 degrees C in a linear temperature gradient apparatus, compared with 81% for adult males..