There are 533 different word forms of fish names in 220 categories in Jeju dialect. Even though some names like ``godeung-eo and godeung-e``, ``Jeon-eo and Jeon-e``, ``Cheong-eo and cheong-e`` are similar to standard Korean, much more fish names are different in Jeju dialect. Dialect forms are also different depending on its phonological environment, for example, ``gaeori, gaeuri and geori`` for the word ``gaori (ray in English)``, while some words have totally different forms. ``gajemi, napsemi, deokge, waenunbegi and sinchakgwegi`` are used to call ``gajami (flatfish)``. Furthermore, there are even 15 word forms for ``okdom (tile fish)`` which is famous in Jeju Island. Some names are different depending on their colors. ``gamseongdom (black porgy)`` has black body so it is called ``geomeundom``. ``multosaegi`` is another name for it, which is liken to a black pig. Moreover, names with ``cham`` mean it tastes good, for example, ``cham-godeung-e``. Fish names in Jeju dialect vary depending on the species. In this study, the names are divided into hypernyms and hyponyms and then categorized according to 1) size, 2) age, 3) sex, 4) habitats, 5) quality and 6) seasons when the fish caught. Some are prefixed with ``dae, jung and so`` or ``keun-, junggan-(or jeong-e) and jogeun-`` depending on the size of fish. 10 kinds of fish which have different names between fry and adult fish are searched and unique prefixes ``mel-, swi-, sil-, bap- and kkwe-`` are attached to the fry`s names. Other prefixes like ``ga-, gai-, deui-, badang- and mosal-`` are related to the fish`s habitats and shown whether the fish lives in sea or sand. ``Bom-galchi`` ``yeoreum-galchi`` and ``gaeul-galchi`` are different names of hairtail used depending on the season when it is caught. Some names are used differently between male and female and cocktail fish is one example. A few mistakes are corrected from other old studies.