Bluebanded Ronquil, Rathbunella hypoplecta
Bluebanded Ronquil, Rathbunella hypoplecta, Female. Fish caught from coastal waters off Santa Cruz, California, August 2021. Length: 16 cm (6.3 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
Bluebanded Ronquil, Rathbunella hypoplecta, Female. Fish caught from coastal waters off Santa Cruz, California, August 2021. Length: 16 cm (6.3 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
The Bluebanded Ronquil, Rathbunella hypoplecta, is a member of the Bathymasteridae or Ronquil Family, that is also known as the Smooth Ronquil, the Stripefin Ronquil, and the Stripedfin Ronquil, and in Mexico as ronco pelón aletirrayada and ronco pelón rayado. Globally there are two species in the Genus Rathbunella, both of which three are found in Mexican waters of the Pacific Ocean.
The Bluebanded Ronquil has a blenny like body. They are an olive brown to dull red, bluish black or purple color with lighter areas. They have a longitudinal blue stripe that runs the length of the anal fin. The males have several prominent blotches on their sides; the females are relatively pale with darker splotches and spots dorsally with light barring on the lower sides and a blue spot on the anterior of the dorsal fin. They have a long anal fin with 33 rays, that does not have spines and has a uniform height for its entire length, a rounded caudal fin, a dorsal fin that has 46 rays the first five of which are unbranched, no spines, and a uniform height, large and rounded pectoral fins and pelvic fins that are found on the thorax with 1 spine and 5 rays. They are covered with small smooth scales. Their prominent lateral line is high on the body and straight.
The Bluebanded Ronquil is a demersal solitary species that is found in shallow exposed coastal waters within rocky structure and substrate on at depths up to 178 m (585 feet). They reach a maximum length of 28 cm (11 inches). They consume invertebrates including amphipods, copepods, polychaetes, shrimps, and snails. In turn they are preyed upon by a wide variety of fish and Sea Lions. Reproduction is oviparous with batch spawning with external fertilization; each female releases eggs in protected locations among rocks and is guarded by the males. The Bluebanded Ronquil 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 Bluebanded Ronquil is a resident of Mexican waters of the Pacific but has a limited distribution, being found from Santo Tomás, Baja California, northward along the northwest coast of Baja.
The Bluebanded Ronquil is easily and often confused with the Rough or Stripefin Ronquil, Rathbunella alleni (smaller in stature; canines on the lower jaws). The separation of these two species is exceedingly difficult even for experienced professional ichthyologists.
From a conservation perspective the Bluebanded Ronquil has not been formally evaluated. They are relatively small in stature and of limited interest to most.