When the tide is out, these snails tend to cluster together in moist places, hiding in crevices or under rocks. As soon as the tide comes in, they disperse to graze on
microalgae. As in other members of the family Planaxidae, fertilisation is internal, and the
embryos are retained in a brood chamber located behind the female's head. They are liberated into the sea and become
planktonic at the
veliger larval stage. When disturbed,
Hinea brasiliana emits a series of short flashes of bluish-green light. Impact with a fast-moving object brings on a more intense
bioluminescent response. The light is produced from the
mantle tissue and shines through the pale translucent shell, which acts to diffuse the light so that the whole shell glows. The light may serve to startle or dazzle a potential
predator, and is emitted while the soft parts of the snail remain protected by its shell. It has been found that all other wavelengths of light are transmitted through the shell material and it is only the blue-green wavelength that is selectively diffused, effectively amplifying it and making its originator seem larger. The diffusion through the calcified shell is more efficient than through the best comparable commercial diffusers. As well as scaring away a persistent attacker such as a
crab, the light might have a further defensive function in attracting a larger creature to prey on the crab, in the "burglar alarm" effect. ==References==