Yellow-edged Moray, Gymnothorax flavimarginatus
Yellow-edged Moray, Gymnothorax flavimarginatus. Fish caught from coastal waters off Kona, Hawaii, March 2021. Length: 1.12 m (3 feet 8 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
The Yellow-edged Moray, Gymnothorax flavimarginatus, is a member of the Moray and Snake Eel or Muraenidae Family, that are also known as the Yellow-margined Moray and in Mexico as Morena de borde amarillo. Globally, there are one hundred sixteen members in the genus Gymnothorax, of which eighteen are found in Mexican waters, nine in the Atlantic and nine in the Pacific Ocean.
The Yellow-edged Moray has a stout elongated muscular compressed body that tapers gradually to a blunt tail. They are a yellowish color and covered with dense and finely mottled dark brown spots. They have a large black spot covering their gill openings. The margins of the anal and dorsal fins are greenish-yellow. Their eye is orange. A portion of the juvenile population is bright yellow with brown blotches. The mouth is equipped with a single row of 1 to 3 canine teeth at the front of the top jaw and their teeth are set on the sides of the top jaw in two rows. Their anal and dorsal fin are covered with skin; the dorsal fin originates just before the gill opening. They do not have pectoral or pelvic fins, gill covers or scales. They are covered with thick yellow mucus, which provides them with protection from abrasion. Their tail is slightly greater than 50% of their body length.
The Yellow-edged Moray is a widely distributed inhabitant of rocky areas of seaweed covered reefs and protected shorelines at depths up to 150 m (500 feet). They reach a maximum of 1.24 m (4 feet 8 inches) in length. They take shelter during the day backing into crevices within rocky structure with only their head protruding. Their body shape and the lack of fins, scales, or gill covers allow them to move quickly in and out of rocky crevices. They are known to be very curious. They are voracious nocturnal ambush predators with poor eyesight that utilize their keen sense of smell to seek out prey, that consume cephalopods, crustaceans, and fishes. They have generated an interest from the scientific community due to their habit of emerging during daylight hours to pursue speared fish indicative that they are sensitive to stimuli emanating from an injured or stressed fish. Reproduction is viviparous with eggs and sperm broadcast into the water generating pelagic eggs and larvae. The Yellow-edged Moray is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Yellow-edged Moray is a resident of Mexican waters of the Pacific but has a limited distribution being found as the extreme tip of Baja California and the Revillagigedo Islands.
The Yellow-edged Moray can be confused with the California Moray, Gymnothorax mordax (yellowish brown, with dense dark spot; gray eye).
From a conservation perspective the Yellow-edged Moray is currently considered to be of Least Concern with stable, widely distributed populations. They are utilized by the aquarium trade at a nominal level. They used by Asian cultures for human food but known to contain ciguatera toxin.