Threebanded Butterflyfish, Chaetodon humeralis
Threebanded Butterflyfish, Chaetodon humeralis. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, July 2012. Length: 12.3 cm (4.8 inches).
Threebanded Butterflyfish, Chaetodon humeralis. Fish caught in coastal waters off Mazatlán, Sinaloa, October 2016. Length: 15.5 cm (6.1 inches). Photograph courtesy of George Brinkman, Guelph, Ontario, Canada.
Threebanded Butterflyfish, Chaetodon humeralis. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2021. Length: 18 cm (7.1 inches). Catch, photograph and identification courtesy of Bart, The Netherlands (worldangler.eu).
Threebanded Butterflyfish, Chaetodon humeralis. Fish caught out from coastal waters off Point Palmilla, Baja California Sur, April 2022. Length: 19 cm (7.5 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
Threebanded Butterflyfish, Chaetodon humeralis. Underwater photographs taken in coastal waters off Puerto Vallarta, Jalisco, September 2021. Photograph courtesy of Kevin Erwin, Seattle, Washington.
Threebanded Butterflyfish, Chaetodon humeralis. Underwater photograph taken in coastal waters off Buena Vista, Baja California Sur, June 2017. Photograph courtesy of Bob Hillis, Ivins, Utah.
Threebanded Butterflyfish, Chaetodon humeralis. Underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2018. Photographs courtesy of Ron Woheau, Zihuantanejo.
Threebanded Butterflyfish, Chaetodon humeralis. Underwater photograph taken in Zihuantanejo Bay, Guerrero, November 2021. Photograph courtesy of Maude Jette, Dive Zihuantanejo, Divezihuantanejo.com.
The Threebanded Butterflyfish, Chaetodon humeralis, is a member of the Butterflyfish or Chaetodontidae Family, and is known in Mexico as mariposa muñeca. The Butterflyfishes are reef fishes and some of the most colorful tropical fishes in the ocean. Globally there are ninety-three species of Butterflyfish of which ninety-two are found in the genus Chaetodon, five of which are found in Mexican waters, four in the Atlantic and one in the Pacific Ocean.
The Threebanded Butterflyfish has a body that is a strongly compressed oval disc that has a depth that is 62% to 66% of standard length. They are very distinctively colored with 3 black bands across a silvery white to yellowish brown body, 1 runs through the eye, and a caudal fin with 2 additional dark narrow bands. The head has a short pointed snout with a small terminal mouth that is equipped with long and slender teeth. Their anal fin has a bluntly angular rear margin and has 3 spines and 15 to 17 rays with the second spine being longer than the third; their caudal fin is straight or slightly rounded; and, their dorsal fin has a bluntly angular rear margin and has 13 spines, that increase to the fourth or fifth spine and then decrease in length, and 18 to 25 rays. Their body is covered with rough scales. Their lateral line is incomplete with a high arch.
The Threebanded Butterflyfish is found in pairs or in small schools in and around rocky areas near shore at depths up to 107 m (350 feet). They are known to enter estuaries and within mangroves and lagoons. They are also known to school with the Pacific Spadefish, Chaetodipterus zonatus. They reach a maximum of 26 cm (10.6 inches) in length. They feed on algae and benthic invertebrates. Reproduction is oviparous. The Threebanded Butterflyfish 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 Threebanded Butterflyfish is a resident of all Mexican waters of the Pacific Ocean and are more common along the coast of the mainland. They are the most common Butterflyfish in the Tropical Eastern Pacific Ocean.
The Threebanded Butterflyfish is most likely confused with the Barberfish, Johnrandallia nigrirostris (black bands on the snout, across the eyes and forehead, and along the base of the dorsal fin), and the Scythe Butterflyfish, Prognathodes falcifer (inverted black “V” upper body).
From a conservation perspective the Threebanded Butterflyfish is currently considered to be of Least Concern with stable widely distributed populations. The major concern at present for their long-term survival relates to habitat degradation and loss of the coral reefs in which they reside. They are a popular aquarium item due to its beauty and hardiness and sold commercially for the aquarium trade.