reciprocally coelomic fluid serves hydroskeleton maintaining turgidity earthworm ref name gardner ref animals mollusks nematodes possess obliquely striated muscles contain bands thick thin filaments arranged helically rather transversely like vertebrate skeletal cardiac muscles ref name alexander ref advanced insects wasps flies bees beetles possess asynchronous muscles constitute flight muscles animals ref name alexander flight muscles often called ''fibrillar muscles'' contain myofibrils thick conspicuous nervous system mouse pyramidal neurons green
Natural science Biology