Does 'sewer crabs' insinuate any other meaning?

Question

The second old man threw his axe down pettishly, spat in the direction of the closed door and went off among the stacks of cordwood.

The door of the shack opened, the man in the Mackinaw poked his head out of it. "Sewer crabs is all," he said, and slammed the door again. I put my dollar in my pocket and went back up the hill. I figured it would take too long to learn their language.

[from 'Goldfish' by R. Chandler]

It is difficult to find out any specific meaning of 'sewer crabs' as used above in any kind of dictionaries.

My guess is:

The old man is just grumbling, and he is talking about something to eat in his shack. In fact he is complaining about eating same crabs everyday.

I heard the sewer crab is kind of fresh water crab, and sometimes live on in sewer.

But the location of the above dialogue is in Westport, facing the Pacific, where sea crabs are abundant. (a western-tip of USA) So no point in eating sewer crabs there. (I've never been there actually.)

My point is 'it is a cursing remark, not meaning any real sewer crabs'.

Hoping my long explanation just makes a bit of sense.

Answer 1

Google Books has a link to (a lot of) the Raymond Chandler story you're asking about. It also has links to three other versions of the same story—but no other matches for "sewer crab" or "sewer crabs" at all. So I think maybe "sewer crabs" is just a little invention of Raymond Chandler's. The closest I could get to an entry for "sewer crab" in the slang dictionaries I consulted was this entry for "sewer hog" in Harold Wentworth & Stuart Flexner, Dictionary of American Slang (1960):

sewer hog A ditch digger for a construction company or road-building firm.

So arguably the old man in the Mackinaw might have been using "sewer crabs" to refer to people who live, sleep, work, or in other ways spend lots of time in ditches. But since Philip Marlowe didn't stick around to learn the language, we don't have much of a clue what the old man meant. It certainly isn't a widely recognized U.S. slang term—not then and not now.

It was all a wild crab chase. Yargs stood up slowly, scanned the moldering docks one last time, and followed the receding figure of Marlowe up the hill.

Answer 2

Not sure why, but my googling yielded meaningful results. Apparently there are sewers that are home to crabs. There are also, apparently, people who fish for them.

I will pull out a few additional sentences from the sewer crab section of the book, to provide more context for the old man's answer:

I left by the coffeeshop door and walked down a hill to where the last, loneliest reach of Puget Sound died and decomposed against a line of disused wharves.

I set a box on end, sat down, filled my own pipe, lit it, puffed a cloud of smoke. I waved a hand at the water and said: "You'd never think that ever met the Pacific Ocean."

"Know anybody around here that keeps a lot of goldfish?"

Now, my interpretation of the Mackinaw man's answer ("Sewer crabs is all"): The conversation takes place at water's edge. The water in question is dirty, similar to the water in a sewer. There is a type of crab that is adapted to living in sewers, and it is able to live in the dirty water where the scene takes place. The man who answers the narrator's question tells the narrator that he doesn't know anyone who keeps a lot of goldfish, he only knows people who keep (or fish for?) sewer crabs.

I haven't read past this, so I don't know for sure, but I can say that the scene gave me the impression this particular avenue was a dead end in the narrator's investigations. It seemed to me that Chandler in this scene was simply creating an ambience, of dockside seediness. (I know enough of Chandler to know that he was into describing seediness.)