This story is very common in Jamaica. See Milne-Home, 91-93, and compare Renel 1:203-204; 206-208 (origin of water-beings); Renel 2:268-269; Parsons, Andros Island, 61, and note for references; Sea Islands, 137.
In Smith, 573-584, a young man changes into a fish in order to escape the attentions of the ladies. He comes out when his mother calls him. He is finally lured out and caught in the meshes of his lover's hair.
In Grimm 8, Bolte u. Polívka 1:69--70, a little girl is forced by her brothers to go out and cut peat with a dull knife. Her elf-lover stretches out a sharp knife to her from the hill where he lives and tells her to call him by striking on the stone. The brothers wonder how she can cut the peat, and spy upon her. They strike the stone, take the knife and cut off the elf's hand, who thereafter disappears.