Meeting Abstract
Anosteocytic bone, bone that is characterized by the lack of osteocytes, has been observed in many higher order fishes. There is little difference in stiffness and strength between anosteocytic and normal bone, however there is an in vivo measurement showing higher strain rates than mammalian cellular bone. We supposed this might indicate a higher energy to fracture anosteocytic bone than cellular bone. A pendulum was constructed with a motorized release mechanism for a steel bob. The opercles of the great sculpin (Myoxocephalus polyacanthocephalus) and Chinook salmon (Oncorhynchus tshawytscha) were dissected, cut into a uniform size with a laser cutter, subjected to a Chapry Impact test, and recorded using high speed video. The laser cutter proved to be capable of very precise sample generation with minimal edge damage due to heat. Loss of kineic energy in fracturing the bone sample was reflected in a decrease in the height of the pendulum bob after striking the sample. The mean energy required to fracture acellular bone was 2430.6±390 J/cm2. The mean amount of energy required to fracture cellular bone was 2040.1±530 J/cm2. The amount of energy required to fracture acellular and cellular bone were not significantly different (p=0.35). We cannot support the hypothesis that anosteocytic bone is tougher than bone with a normal distribution of osteocytes.
