Enhanced vascularization of the central nervous system in two species of mud-burrowing fish

Synopsis Histological studies have demonstrated a significantly richer vascularization of the brain and anterior spinal cord tissues in the mud-burrowing gobies Brachyamblyopus sp. and Trypauchen sp. than three fish species that occupy a variety of non-burrowing habitats. Physico-chemical data from the mud-burrowing gobies' habitat indicate anoxic conditions in the substrate. It is suggested that the enhanced development and distribution of blood capillaries throughout the central nervous system of these two goby species may be a morphological adaptation to their environment. Appropriate physiological studies are needed to clarify this contention.