Gymnothorax mucifer Snyder 1904
     Tyler Dreiling photographed this unusual eel off Maui at a depth of about 80 ft. in February 2020. He couldn't identify it and sent the photo to me, asking if it might be Steindachner's Moray (Gymnothorax steindachneri), an endemic eel that is common in the Northwestern Hawaiian Islands but quite rare in the main islands. It didn't look quite right to me for Steindachner's, so I toyed with the idea that might be a Lipspot Moray (G. chilospilus), which is also quite rare in Hawaii. However, it lacked the required faint white spot on the lip. The Kidako Moray (G. kidako), also very rare in Hawaii, was another possibility. While researching that eel I found a 2019 paper by two Taiwanese ichthyologists stating that the eel called G. kidako in Hawaii has been misidentified and is actually Gymnothorax mucifer, an eel that was scientifically described from a specimen found in the Honolulu fish market in 1904 and has rarely been seen since. It has no common name. I sent Tyler's photo to two of the paper's authors, Wen-Chien Huang and Hong-Ming Chen. They wrote back immediately confirming the eel in Tyler's photo as Gymnothorax mucifer. They pointed out that the true Kidako's Moray has a mottled lower jaw while in Tyler's G. mucifer the lower jaw is solid tan. I wrote to Tyler with the exciting news that the eel in his photo is very rare and that his photo is probably the first underwater photo of Gymnothorax mucifer ever taken in Hawaii. It needed a common name and the best I could come up with was "Plain-Jaw Moray." Tyler then suggested "Bronze-Jaw Moray" which was clearly better. Thanks, Tyler, for your curiousity, your sharp eye, and your verbal skills!

The Bronze-Jaw Moray is known to date from Hawaii, Taiwan, New Caledonia, and Australia while the true Kidako exists only in Japan and Taiwan. In Taiwan the two coexist, which alerted scientists that two similar species were involved.

Here's another photo of the Bronze-Jaw taken in Australia. However, on the website they still use the common name Kidako Moray. Confusing ...

Finally, here's photo from Hawaii of what seems to be a dead Bronze-Jaw, probably caught by a fisherman many years ago. It appears at the bottom of p. 527 of Spencer Wilkie Tinker's 1982 book, Fishes of Hawaii, and is labeled as an unidentified shallow-water moray eel from the southwestern coast of Oahu . (I was led to this photo by Bruce Mundy's massive Checklist of the Fishes of the Hawaiian Archipelago in the comments under G. kidako.)

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Text and photos copyright by John P. Hoover