Panamic Frillfin

Panamic Frillfin, Bathygobius ramosus

The Panamic Frillfin, Bathygobius ramosus, whose Spanish common name is mapo panámico, is a species in the Gobies or Gobiidae Family, known collectively as gobios in Mexico. Globally, there are twenty-seven species in the genus Bathygobius, five of which are found in Mexican waters, four in the Atlantic and one in the Pacific.

The Panamic Frillfins have robust elongated rounded bodies. They are olive green to brown with lighter scale centers, a row of dark spots along their mid-side, and diffuse bars on their back. The lower part of their head has small white spots and there are three blotches behind their eyes, the first of these being the largest. Their first dorsal fin is pigmented with a central stripe and their caudal and second dorsal fins have wavy brown bands or spots. Their head is broad and scaleless and they have a rounded blunt snout and large eyes set very close together. Their caudal fin is rounded and has 24 to 31 rays. Their first dorsal fin has 6 spines and their second dorsal fin has one spine and 8 to 10 rays. Their pelvic fins are close together on the belly. With the exception of the head, their body is covered with large rough scales.

The Panamic Frillfins are tidal pool residents found in rocky habitats at depths up to 10 feet. They reach a maximum length of 20.0 cm (7.9 inches). They feed primarily on algae. They are a small, shallow-water species and very little is known about their behavioral patterns.

In Mexican waters the Panamic Frillfins are found in all waters of the Pacific with the exception that they are absent from Magdalena Bay northward along the central and northwest coasts of Baja.

The Panamic Frillfin is a unique looking fish and not easily confused with other species.

Due to their small size, the Panamic Frillfins are of limited interest to most.

Panamic Frillfin, Bathygobius ramosus, breeding male. Fish collected from a tidal pool at Km 17, El Tule, Baja California Sur, January 2014. Length: 2.5 cm (1.0 inch). Identification courtesy of H.-C. Lin and Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA. Darkened fish believed to be a breeding male and thus melanistic (i.e. very dark in color due a high content of melatin in the skin).

Panamic Frillfin, Bathygobius ramosus. Photo taken of a live fish sitting on a rock out of water mid-day in December 2007, Km 17, El Tule, Baja California Sur. Length: 2.5 cm (1 inch). Identification courtesy of H.-C. Lin and Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.

Panamic Frillfin, Bathygobius ramosus. Fish caught from a coastal tidal pool, October 2015, Mazatlán, Sinaloa, April 2015. Length: 7.8 cm (3.1 inches). Catch and photo courtesy of George Brinkman, Guelph, Ontario, Canada. Identification courtesy of Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.

Panamic Frillfin, Breeding Male, Bathygobius ramosus. Fish caught from a coastal tidal pool, October 2015, Mazatlán, Sinaloa, October 2015. Length: 10.1 cm (4.0 inches). Catch and photo courtesy of Robert Wilson, Cobourg, Ontario, Canada. Identification courtesy of Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.