Panamic Frillfin, Bathygobius ramosus

Panamic Frillfin, Bathygobius ramosus. Fish caught from coastal waters of San José del Cabo Rió, Baja California Sur, April 2022. Length: 6.2 cm (2.4 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.

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, California. 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. Fish caught from coastal waters off Puerto Vallarta, Jalisco, February 2023. Length: 8.1 cm (3.2 inches). Catch and photograph courtesy of Ben Cantrell, Peoria, Illinois.

Panamic Frillfin, Bathygobius ramosus, Breeding Male. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2021. Length: 8.2 cm (3.2 inches). Catch, photograph and identification courtesy of Bart, The Netherlands  (worldangler.eu). 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. Photograph 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 1.0 inch). Identification courtesy of H.-C. Lin and Phil Hastings, Scripps Institution of Oceanography, La Jolla, California.

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 photograph courtesy of George Brinkman, Guelph, Ontario, Canada. Identification courtesy of Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, California.

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

Panamic Frillfin, Bathygobius ramosus. Underwater photographs taken in Zihuantanejo Bay, Guerrero, in December 2022. Photographs and identifications courtesy of Ron Woheau, Zihuantanejo.

The Panamic Frillfin, Bathygobius ramosus, is a member of Goby or Gobiidae Family, and is known in Mexico as mapo panámico. Globally, there are twenty-seven species in the genus Bathygobius, of which five are found in Mexican waters, four in the Atlantic and one, this species, in the Pacific Ocean.

The Panamic Frillfin has a robust elongated rounded body 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 3 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; their second dorsal fin has 1 spine and 8 to 10 rays; and, 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 Frillfin is a tidal pool resident found in rocky habitats at depths up to 3 m (10 feet). They reach a maximum of 20.0 cm (7.9 inches) in length. They feed primarily on algae. The Panamic Frillfin is a small, shallow-water species and 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 Panamic Frillfin is a resident of all Mexican waters of the Pacific Ocean with the exception that they are absent from Magdalena Bay, Baja California Sur, northward along the central and northwest coasts of Baja.

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

From a conservation perspective the Panamic Frillfin is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature and of limited interest to most.