Surf Fishing: Flathead and Mystery Crab

I went fishing yesterday. (Was it a Good Friday thing? Some smoke from a stirred childhood memory?) Christine came along, and spent some time trying to catch beach worms.

Just a few minutes in I caught a flathead on a little prawn (not fresh; been in the freezer for ages). Clean, hard strike, I didn't have to set the hook, it just took it and ran. Christine took a shot of the hook removal:

Now here's the weird thing: The flathead you catch surf fishing around here, the way I understand it, is the dusky flathead. But the dusky flathead, like all flathead species, I'm learning, has a characteristic tail:

Dusky Flathead are easily distinguished from other flathead by the distinctive black spot circled in blue on their tail fin.

Look at this fish's tail. Click on the pic and then again to zoom in.

You see those spots on the tail? I'm pretty sure that tells us this is a Northern flathead:

The Northern Flathead has a pale brown body speckled with pinkish-red spots. The caudal fin (tail) is the best way to identify the northern sand flathead, with a pattern of almost horizontal flag-like black stripes across the tail (three distinct black bars on the upper portion and two on the lower portion of the caudal fin).

Here's an image of a tail.

I quickly got out my book and found that flathead have to be 33 centimeters, about 13 inches—to keep. This one was a few centimeters short, so back into the Pacific he went.

Christine gave up on the beach worms—they're so hard to catch—and went home. About an hour later I felt something tugging on my bait. I yanked the rod, and got something. It felt like a bigger fish that the first. I pulled it in and in the surf saw...what?...the hell is that...damn, it's a crab. He fell off right at the edge of the surf. I don't think I had hooked him—I think he just held on to that piece of pilchard for the whole ride to the beach.

 I have no idea what kind off crab that is. My NSW fishing book lists just three that have size limits; this crab isn't one of those (mud crab maybe); for the rest there is no size limit.

Grrrr.

I put him back anyway. Can't cook up one little crab. He scampered and swam sideways back into the surf.