Antilles Frillfin, Bathygobius antiliensis
Antillles Frillfin, Bathygobius antilliensis. Fish caught from the Sebastian Inlet, Sebastian, Florida, July 2021. Length: 8.1 cm (3.2 inches). Catch, photograph and identification courtesy of Brayden Moore, Peoria, Arizona
The Antilles Frillfin, Bathygobius antilliensis, is a member of the Goby or Gobiidae Family, that is also known as the Antillies Frillfin Goby and in Mexico as Antillean mapo. Globally, there are twenty-seven species in the genus Bathygobius, of which five are found in Mexican waters, four in the Atlantic and one in the Pacific Ocean.
The Antilles Frillfin has a robust body with a broad depressed head that has a bluntly rounded snout, large eyes set close together and a moderate sized mouth that has teeth set in bands on both jaws. They have an overall grayish brown color with the upper body having with three indistinct dark saddles, the central flank has a row of rounded spots that are connected to 7 or 8 dark blotches. The caudal fin has 2 or three dark blotches at its base and dark baron on the outer margin. The first dorsal fin has 1 to 4 dark blotches on each element that form 1 to 4 stripes across the fin or one dark longitudinal stripe across the middle of the fin. The second dorsal has thin dark stripes and a yellowish margin. Their anal fin has 1 spine and 8 rays; their caudal fin is round; their first dorsal fin has 6 spines; their second dorsal fin has 1 spine and 9 rays with its base being of greater length than the distance to the caudal base; their pectoral fins have 18 to 21 rays with the upper three to five being free standing silky threads; and, their pelvic fins are fused to the disk. They are covered with rough scales and they do not have a lateral line.
The Antilles Frillfin inhibit shallow rocky habitats, reef crests and tidal pools in exposed areas at depths up to 3 m (10 feet). They reach a maximum of 9.5 cm (3.7 inches) in length. They feed primarily on algae. The Antilles Frillfin 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 Antilles Frillfin can be confused with the Checkerboard Frillfin, Bathygobius lacertus (lower body with two off set rows of 6 or 7 blotches), the Frillfin Goby, Bathygobius soporator (three saddles dorsally and six or seven blotches on the flank), the Island Frillfin, Bathygobius mystacium (three saddles dorsally, one row of six large squares blotches ventrally, caudal base with two dark spots, dorsal fin with one to three stripes and a yellow margin), the Notchtongue Goby, Bathygobius curacae (lacks a diagnostic color pattern).
The Antilles Frillfin is a resident of all Mexican waters of the Atlantic Ocean but is limited to coastal waters adjacent to the Yucatán Peninsula from Vera Cruz to Belize in the Caribbean.
From a conservation perspective the Antilles Frillfin is currently considered to be of Least Concern with stable, widely distributed populations. Due to their small size they are of limited interest to most.