The DNA Sampling Hook is a significant improvement on a method of obtaining a tissue sample from a live fish in situ from an aquatic environment. A tissue sample taken from a live fish can be used for DNA analyses, which can identify the species of fish, as well as the unique individual fish. Taking a small tissue sample without bringing the fish to the surface is important as it allows for observing the fish community without harming the individual fish by inducing barotrauma or other stresses associated with bringing a fish up from depth, which can be lethal to the animal. These tissue samples are obtained by hook and line methods and do not capture or traumatize the fish resulting in a non-lethal and non-destructive method of observing fish individuals and species. The DNA Sampling Hook is specifically designed to virtually eliminate a condition called double bites, in which more than one individual fish gives up tissue to the same hook. It is also designed to protect the tissue sample in an enclosed manner and the device can be reused repeatedly for a total overall reduction in cost for programs requiring extensive numbers of tissue samples for DNA analysis.