Blackwing Searobin, Prionotus rubio

Blackwing Searobin, Prionotus rubio. Fish caught from coastal waters off Palm Beach, Florida, December 2022. Length: 14 cm (5.5 inches). Catch, photograph and identification courtesy of Ben Cantrell, Sebastian, Florida.

Blackwing Searobin, Prionotus rubio. Fish caught from coastal waters off Palm Beach, Florida, December 2022. Length: 17 cm (6.7 inches). Catch, photograph and identification courtesy of Ben Cantrell, Sebastian, Florida.

The Blackwing Searobin, Prionotus rubio, is a member of the Searobin or Triglidae Family, and are known in Mexico as rubio aletinegra. Globally, there are twenty-three species in the genus Prionotus, of which fifteen are found in Mexican waters, ten in the Atlantic and five in the Pacific Ocean.

The Blackwing Searobin has a rectangular block-like body that is gray brown in color that varies. Their head has a long sloping snout with a large subterminal mouth that extends to the front of the eyes that has a a long preopercular spine that extends past the margin of the gill cover. Their anal fin is transparent; their caudal fin has three bars and has a red margin; their first dorsal fin is dusky with three spines that have black tips and two bars or spots along the base and the second dorsal fin has one along the base; their pectoral fins are a uniform black color with bright blue ventral margin; and, their pelvic fins are covered with black spots. Their first dorsal fin has 9 to 11 spines with the posterior spines being very short; the second dorsal fin has 12 or 13 rays; their pectoral fins are elongated, with 13 or 14 rays with the last three lower rays being free and much longer than the upper rays, that extend beyond the anal fin origin. They are covered with scales.

The Blackwing Searobin is found demersally in bays and estuaries to the mid-shelf at depths up to 210 m (690 feet). They reach a maximum of 30 cm (12 inches) in length. The Blackwing Searobin 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 Blackwing Searobin is a resident of Mexican waters of the Atlantic Ocean but has a limited distribution being found only in the Gulf of Mexico from the Texas border to the extreme southwest corner of the Yucatán Peninsula. They are absent from around the Yucatán including the east coast in the Caribbean.

The Blackwing Searobin can be confused with a series of other Searobins found in Mexican waters of the Atlantic Ocean including the Bandtail Searobin, Prionotus ophryas, the Bluespoted Searobin, Prionotus roseus, and the Spiny Searobin, Prionotus alatus, but they are a very straight forward identification due the bright blue band on the front margin of their pectoral fins.

From a conservation perspective the Blackwing Searobin is currently considered to be of Least Concern with stable, wide-ranging populations. Due to their bony structure and rarity, they are of limited interest to most. They are a caught as a by-catch of deepwater shrimp trawlers.