Yes, they do. But I didn't know that was what they were for! Wow!
By suggestion of the fellow I bought my boat from, the holders were installed so you wouldn't/couldn't get close enough to the bibs below to bung your ankles. They have worked out famously as the four holders in the gunnels aren't nearly enough. If I'm fishing a side I don't want a spare rod sitting in the holder there anyway, so these ones at the rear work out great.
They are also handy for standing a rod while fishing out a bait from the tank. The pads on the floor are the Kodiak mounts for a 32gal oblong. It is only mounted up when we are actually fishing, the outflow goes over the motorwell. The pump is connected to the starboard hose bib, and is mounted on a bronze thru-hull. A new ShurFlo bait sentry 800gpm works really well, albiet a bit noisy. We've held 'dines, anchovies, and squid.
I would have to go look up the reciept to recall where they came from, were about $50 each. Let me now if you need a source.