They use their fins to fight off predators

Mosquito larvae, small crustaceans, plant material, and William Lin

To name a few, oysters, mud snails, octopus, mussels, horseshoe crabs, stickleback fish, mummichog fish, and clams.

Marc C Albrecht has written:

'Differential survivorship of Fundulus heteroclitus (Cyprinodontidae) exposed to pentachlorophenol or methylmercury as detected by allozyme electrophoresis' -- subject(s): Toxicology, Animal models, Methylmercury, Genetic toxicology, Mummichog, Pentachlorophenol, Isoenzymes

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern --M---H-G. That is, nine letter words with 3rd letter M and 7th letter H and 9th letter G. In alphabetical order, they are:

mummichog