(1) The 10-fold seasonal differences in FMR were reasonable for an ectothermic poikilotherm .(2) Little is known about the physiological time of poikilothermic animals and we know nothing about the physiological time of modular organisms.(3) As evidenced by the articles in this volume, a recent increase in interest in the mating systems of poikilothermic vertebrates has focused primarily on fishes, a few amphibians, and squamate reptiles.(4) Because amphibians are poikilothermic , this unequal geographic distribution might have led to shorter generation times and higher metabolic rates in the evolution of neobatrachians.(5) However, some poikilothermal animals do not have a high concentration of SM and HSM in their lens.(6) In addition to sequence length, differences between homeotherms and poikilotherms (hagfish, gray mullet, zebrafish, toad, and snake) occur at positions 373 and 400, respectively.(7) On the positive side, there is substantial evidence that poikilotherms have lower metabolic rates and longer life spans at cooler temperatures (reviewed by FINCH 1990; ARKING 1998).(8) This is distinct from poikilotherms , such as reptiles and amphibians, whose body temperature is just above the ambient temperature, and varies with it.(9) Winters may be shorter but they will still be very cold, while concomitant changes in insulating snow cover will have other effects on these poikilotherms .(10) In poikilothermic animals temperature can be a major variable.(11) General anesthesia inactivates the body's temperature regulating mechanism and transforms the homeothermic body into a poikilothermic body - one that is altered by the temperature of the environment.(12) This mode of thermoregulation, that can neither be classified as homeothermy (constant temperature as in birds or mammals) or poikilothermy (as in fish, amphibians and most reptiles), has been called gigantothermy.