Submerged spawning and larval dispersal of the mudskipper Periophthalmus variabilis

Since the discovery of mudskipper aerial embryonic incubation in 1998, it has been unclear whether spawning and fertilization take place inside an air-filled or water-filled egg chamber, and whether the parent animals help the newly hatched larvae leave the hypoxic water inside the burrow. I can confirm submerged spawning, observed in video recordings of the egg chamber of a mudskipper Periophthalmus variabilis burrow. Initial indirect evidence was ob tained by video recordings of water level increases at the entrances to the burrow caused by the male adding air into the egg chamber, displacing the water there. Furthermore, single video recordings show that the male can create a strong water current that causes water to flow out of the burrow, which may help the larvae leave the burrow.