Terrestrial Redfish use Vestigial Fin-Legs

Yes, Redfish got legs. It's true. Here's a similar, earlier image of what I observed yesterday at high noon:

     With important differences: the above redfish was placed at the shoreline edge prior to my releasing him after capture with my little #4 Redfish Rusty. He just posed there as he collected himself, ready to go. In resuscitation of reds after capture, they always quite amiably allow me to put my thumb in the corner of their mouths, open them slightly for circulation,  and grab their caudal peduncle (tail juncture) and move them forward slowly through the water to pick up their O2 level. They actually gently hold on to my thumb  while they're recovering, and simply let go of it when they're ready to swim off. It's a team effort.
     The greatest difference in what I observed yesterday is that that particular redfish had placed himself half out of the water of his own accord and was cruising with his eyes in and out of the water just like in the picture as he hunted for, as I observed, little dime and quarter sized crabs of what appeared to be the blue variety. His splayed pectorals were possibly functional--at least partially--as legs over the sand and seagrass, though his tail I think did most of the forward propulsion work as I watched him. Cruising along slowly, he would occasionally have to rise up out even more of the water, his belly on the sand,  as he crested the hard sand ridges of stingray beds dug into the sand in this particular spot. The topography demanded it. On the crest of the ridge, this fish would tuck in those backward-sweeping pecs to narrow his profile and I believe, provide a backward thrust. Critically, he maintained buoyancy at all times, and never appeared to approach actual "beaching" of himself. But he walked that edge, man. He was living.
     Some forty feet away, I cast a fly vaguely in front of him and he slowly and casually vanished into the glare of the deeper water at the edge of the sand flat. I think he'd seen me before I cast.