Place the water, bouillon cubes, onion, tomato, and bell pepper in a large pot and bring to a boil.
In a saute pan melt the butter on medium high heat and add the peices of cat fish in the pan. Season the fish with lime juice and salt and cook on medium high for 4 minutes until the skin starts to peel from the fish. Turn the pieces over, season with lime juice and salt and cook for an additional 4 minutes.
Turn down the heat on your pot to medium and carefully add in the cat fish, shrimp, mussels, octupus, crabs and squid. Add the minced cilantro and the epazote and stir the top just to barely incorporate the cilantro.
Cover the pot and cook on medium for 15 minutes. Turn the heat off and allow the soup to sit for 5 additional minutes.
Serve the soup with fresh limes, salt, and corn tortillas. Sometimes I even dice onions, cilantro and radishes for garnish.
Note; You can also buy a bag of frozen seafood which would include squid, mussels, octupus, and baby shrimp. This can replace the seafood ingredients except for the large shrimp, crabs, and catfish.