Swordspine Croaker, Bairdiella ensifera
Swordspine Croaker, Bairdiella ensifera. Fish caught from coastal waters off Puerto Chomes, Costa Rica, March 2021. Length: 26 cm (10 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).
The Swordspine Croaker, Bairdiella ensifera, is a member of the Croaker or Sciaenidae Family, and is known in Mexico as ronco barbirrubia. Globally, there are five species in the genus Bairdiella, and all five are found in Mexican waters, two in the Atlantic and three in the Pacific Ocean.
The Swordspine Croaker has an elongated, oblong compressed body. They are silvery in color with a dark spot on the axil of the pectoral fins. The anal, caudal, pectoral and pelvic fins are yellowish. The tip of the lower jaw is black. Their head is narrow with a short blunt snout. They have a large slightly oblique mouth that opens in the front, reaches the rear edge of the eyes, and is equipped with conical teeth set in narrow rows. They do not have barbels. Their anal fin has 2 spines and 8 or 9 rays with the second anal spine being both strong and long which gives rise to their common name; their caudal fin is bluntly pointed and reaches the caudal fin; their first dorsal fin has 10 spines; and their second dorsal fin has 1 spine and 22 to 24 rays with a deep notch in between. Their gill covers have 8 to 12 spines including 2 or 3 strong spines set at an angle. They have 24 to 26 gill rakers. They are covered with rough scales. Their lateral line extends to the center of the caudal fin.
The Swordspine Croaker is a demersal species that is found in coastal regions, estuaries and river mouths over sandy and muddy substrate at depths up to 20 m (65 feet). They reach a maximum of 35 cm (14 inches) in length. They feed on crustacean larvae, shrimp, and small fish. In turn they are preyed upon by a variety of larger fish and various sea mammals. The Swordspine Croaker 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 Swordspine Croaker is a resident of Mexican waters of the Pacific Ocean but has a limited distribution between found from Mazatlán south to the Guatemala border.
The Swordspine Croaker is can be confused with, the Armed Croaker, Bairdiella armata (elongated pointed snout, mouth opens under the snout; 21 to 23 dorsal rays; rounded caudal fin) and the Bairdiella, Bairdiella icistia (25 to 29 dorsal rays; second anal spine does not reach the caudal fin).
From a conservation perspective the Swordspine Croaker is currently considered to be of Least Concern with stable, widely distributed populations. They are considered to be a quality food fish and actively pursued by artisanal fishermen.