A Unique Feeding Method by a Teleost Fish, the Fourhorn Poacher Hypsagonus quadricornis (Agonidae)

Fish rarely move inanimate objects when seeking prey, and those few that employ such foraging strategies typically use the mouth to grasp materials. The fourhorn poacher (Hypsagonus quadricornis), a benthic North Pacific species, displays a unique ability to manipulate objects and uncover prey by a method that does not involve the mouth. Rocks and shells are lifted and overturned using the fingerlike, free rays of the pectoral fins, leaving the mouth available for prey capture. The prevalence of this behavior in captive specimens, coupled with evidence from the stomach contents of those collected in the field, suggests that this is the primary means by which this fish forages. [PUBLICATION ABSTRACT]