The morphology and vasculature of the respiratory organs of terrestrial hermit crabs (Coenobita and Birgus): gills, branchiostegal lungs and abdominal lungs

摘要: Abstract The morphology and vasculature of the respiratory organs terrestrial coenobitids were studied using light microscopy, TEM, SEM corrosion casting. gills Coenobita Birgus are modified for air-breathing but reduced in number size have a comparatively small surface area. branchiostegal lungs (which live gastropod shells) very well vascularized thin blood/gas barrier. has developed third organ, abdominal lung, that is formed from highly patches intensely-folded dorsal integument. Oxygenated blood this returned to pericardial sinus via (in parallel circulation). Birgus, which does not inhabit shell, complex lung expanded laterally evaginated increase diffusion distance short oxygenated directly pericardium pulmonary veins. We conclude presence protective mollusc shell hermit crabs favoured evolution an its absence been developed.