Possible Clues:

• Unwilling to share
• Ungenerous and small, like a fairy
• Concerned only with number one
• Mercenary to work at Billingsgate, it's said
• Having I-strain?
• That sounds like what Molly Malone did, not necessarily what she was
• Dog-in-the-manger
• Greedy
• Egocentric - greedy
• Not generous to have seafood for sale like this