Mama Jo is the name of a beautiful snake water spirit or mermaid spirit in the folklore of the the Carolina islands and the West Indies. Her name is dervied from the French Maman de'leau, "Mother of the Water." Mama Jo's assistance in curing disease must be requested on a beach.
According to the healing spell recorded by Judika Illes, a person requesting help from Mama Jo gathers a small image of a either a black goat or black chicken, a lighter, and silver candles. The person must bring the same number of candles as the age of the ailing person--one candle for each year.
At the water's edge, s/he will scoop out sand to make a flat offering space. S/he will place the small image of the goat or chicken with the candles in the offering space and then light the candles.
Whoever is calling Mama Jo will then step barefoot into the shallows of the water, explaining what she brought and exactly what s/he wants. Mama Jo can draw way the sickness. Salt water is soothing on a number of skin ailments.
After the candles burn down, s/he will extinguish the candles and remove the stubs. The animal image must be left behind.
"Mama Jo" seems to swim through Caribean folklore in a number of guises. In Trinidad, she is "Mama Dglo." Mama Dglo is half beautiful woman on top and half water snake down below. In Jamaica, she is the "Riba Muma" or "River Mumma." In Dominica, she is "Maman de l'Eau." There are those who trace her back to the West African "Mami Wata" or "Mammy Wata."
Robert D. San Souci wrote a wonderful children's book, Sukey and the Mermaid: An African American Folktale (1992), which used this water spirit. In the storybook, Sukey calls Mama Jo by singing to her.