Bloodworms are a HUGE diet for fish in the Atlantic. Porgy, Sheepshead, Sea Bass, Sea Robin, Tautog, Winter Flounder, Fluke, Spot, White Perch and even small ground sharks and rays.
The horse is an herbivor, which means he only eats plant life, grasses mostly. If no grass is available they will need hay and some kind of grain to make sure they get all the nutrition they require....