ABSTRACT
The novel reproductive strategy of filling an egg chamber with air, instead of water, as employed by mudskippers, ensures 30 times more oxygen available to embryos in same volume, and oxygen rapidly diffuses to the surface of egg membranes. The novel reproductive strategy of filling an egg chamber with air, instead of water, as employed by mudskippers, ensures 30 times more oxygen available to embryos in same volume, and oxygen rapidly diffuses to surface of egg membranes. Oceanic hypoxia has occurred through geologic time irrespective of recent human impacts. Hypoxia occurs in huge volumes at intermediate depths of the oceans. Organisms in these areas, known as "oxygen minimum zones", have evolved various adaptations to living in oxygen-poor environment. Mudskippers monitor and maintain oxygen concentration of air within burrow by repeatedly renewing it during incubation. Males actively trigger hatching by submerging the eggs in hypoxic water at an appropriate time to coincide with rising tides at night.
