It could be because they display a horizontal diurnal migration
pattern like some hydro- and scyphomedusae (Hamner and Hauri, 1981; Arkett, 1989; Hamner et al., 1994) and that they leave the nearshore area during the day to remain active in another habitat.
The fish, in their turn, carried out the opposite diurnal migration
, feeding in the surface layers in the mornings and moving to intermediate depths later in the day and at night.
Wind drift, leading lines, and diurnal migration
. Wilson Bull, 79:50-63.
and vertical distribution of phyllosoma larvae of the western rock lobster Panulirus cygnus.