Northern Fraildisc Clingfish, Pherallodiscus funebris
Northern Fraildisc Clingfish, Pherallodiscus funebris. Fish caught from a tidal pool in coastal waters of Las Conchas Beach, Puerto Peñasco, Sonora, November 2022. Length: 3.8 cm (1.5 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
Northern Fraildisc Clingfish, Pherallodiscus funebris. Fish caught from a tidal pool in coastal waters of Las Conchas Beach, Puerto Peñasco, Sonora, March 2023. Length: 3.8 cm (1.5 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona. Identification reconfirmed by Dr. Ross Robertson, Smithsonian Institute, Panama City, Panama,
The Northern Fraildisck Clingfish, Pherallodiscus funebris, is a member of the Clingfish or Gobiesocidae Family, that is known in Mexico as chupapiedras discofrágil norteñ. Globally, there are three species in the genus Pherallosicus, of which two are found in Mexican waters, both in the Pacific Ocean.
The Northern Fraildisc Clingfish has a broad slightly depressed body with a relatively slender and depressed head. They are an overall dark chocolate brown color with mottling on the top and sides and a thin dark bar under the eyes. Overall the fins are dark with the pectoral fins being lighter in color. The top jaw has a patch of conical teeth, followed by a row of canines, and 3 to 5 pairs of round-tipped incisors at the front of the lower jaws. They have 6 to 7 blunt rakers on the 2nd and 3rd arch. The anus is closer to the anal fin origin than the sucker. The sucker is larger and 3 rows of papilae across the rear. The anal fin has 7 or 8 rays, the caudal fin has 10 rays; the dorsal fin has 10 or 11 rays; and the pectoral fin has 17 to 20 rays.
The Northern Fraildisc Clingfish is a benthic species in the intertidal zone within cobble beaches and found at depths up to 5 m (17 feet) within intertidal rocky areas clinging to the underside of small rocks. They reach a maximum of 12.4 cm (4.9 inches) in length. They feed primarily on small crustaceans, isopods, limpets, and mollusks that they pry off the rocks. They are preyed upon by rockfishes and various sea birds. Reproduction is oviparous. The Northern Fraildisc Clingfish 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 Northern Fraildisc Clingfish is limited to east coast of the Baja within the Sea of Cortez in Mexican waters of the Pacific.
The Northern Fraildisc Clingfish is most likely confused with the Southern Fraildisc Clingfish, Pherallodiscus varius (moderately slender head; 2 rows of papillae across the rear; caudal fin 9 rays).
From a conservation perspective the Northern Fraildisc Clingfish is currently considered to be of Least Concern with stable, widely distributed populations. Their long-term viability is threatened by pollution and human coastal developments. They are too small to be of interest to most. Surprising, they can be caught by recreational hook and line fishermen.