Paternal help in larval release of three mudskipper species

Abstract

After the discovery of aerial embryonic incubation in mudskippers, it was found that the male induces larval hatching by removing the air from the egg-chamber so that the eggs immerse in water. Do the adults provide additional support to the newly hatched larvae to help them leave the life-endangering hypoxic water inside the burrow? This paper compares 18 hatching events of 3 species: dusky gilled mudskipper, Pearse´s mudskipper and slender mudskipper. After air removal 3 different burrow-shape dependent strategies of paternal help for larval burrow leaving were observed: (1) very frequent diving toward the burrow shaft or into the egg-chamber to generate turbulences that can help to propel the larvae toward the water surface; (2) tail-undulation to create a water current out of the burrow that would take along the hatched larvae; and (3) intake of larvae into the paternal mouth, subsequently spitting them out to expel them from the burrow.