Largehead Moray, Uropterygius macrocephalus
The Largehead Moray, Uropterygius macrocephalus, whose common Spanish name is morena cabezona, is a member of the Moray and Snake Moray Eel or Muraenidae Family, known collectively as morenas in Mexico. This fish is also known as the Needletooth Moray. Globally, there are twenty-one members in the genus Uropterygius, four of which are found in Mexican waters, one in the Atlantic and three in the Pacific.
The Largehead Morays have slender elongated bodies that taper gradually and are compressed at the rear. They are brown in color with irregular pink mottling. They lack the black spot around the gill coverings found in many Morays. The tip of their tail has a white or yellow coloration. Their head has a short, stout, and rounded conical snout. Their eyes are small and centered over the middle of their mouth, which is equipped with sharp slender conical teeth. Their front nostril is tubular; their posterior nostril is a small hole with a raised rim above the front of the eyes. Their anal and dorsal fins are very small and visible only as skin-covered ridges near the tip of the tail. Their tail is longer than the head and trunk.
The Largehead Morays are solitary individuals that inhabit shallow reef areas and are found within cracks and crevices in the subtidal zone at depths up to 45 feet. They reach a maximum length of 47 cm (19 inches). They are nocturnal ambush predators with poor eyesight that utilize their keen sense of smell to seek out prey, consuming small fish and invertebrates including crab, octopus, and shrimp. Reproduction is viviparous with eggs and sperm broadcast into the water generating pelagic eggs and larvae that drift in oceanic currents before settling out on the bottom. They are an uncommon and poorly studied species and very little is known about their behavioral patterns.
In Mexico the Largehead Morays have a limited distribution being found only in the lower half of the Sea of Cortez and along the coast of the mainland south to Guatemala.
Due to the unique mottling covering its sides (pictured below), the Largehead Moray cannot be confused with any other species.
The Largehead Morays are of limited interest to most and normally a “catch and release”. Visually they are most intimidating but are very timid and not harmful. They seldom bite humans.
Largehead Moray, Uropterygius macrocephalus, juvenile. Caught by hand alive and feisty, on the beach above the water line well before first light, at Km 21, Cabo Real, Baja California Sur, July 2006. Length: 23 cm (9.1 inches).
Largehead Moray, Uropterygius macrocephalus. Fish caught from coastal waters off Point Palmilla, Baja California Sur, August, 2015. Length: 45 cm (18 inches). Tail: 47%.