Arrow Goby, Clevelandia ios
Arrow Goby, Clevelandia ios. Fish caught from coastal waters off Santa Cruz, California, September 2023. Length: 6.2 cm (2.4 inches). Catch, photograph and identification courtesy of Ben Cantrell, Peoria, Illinois.
Arrow Goby, Clevelandia ios. Fish caught from within Ventura Harbor, Ventura, California, September 2023. Length: 6.2 cm (2.4 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona.
Arrow Goby, Clevelandia ios. Fish caught from coastal waters off Moss Landing, California, August 2018. Length: 6.4 cm (2.5 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.
The Arrow Goby, Clevelandia ios, is a member of the Goby or Gobiidae Family, that is known in Mexico as gobio fleche. It is the only global member of the Clevelandia Genus. Scientifically they are of interest as they use a signally system to inform other gobies of pending danger and in mating.
The Arrow Goby has an elongated body. They are translucent brownish gray color with darker mottling transitioning to silvery dorsally. The anal fin has a prominent band in males. Their dorsal fins have short horizontal dash-like stripes. Their anal fin has 14 to 17 rays and similar in length to the second dorsal; their caudal fin is rounded; their first dorsal fin 4 or 5 spines and is shorter than and well separated from their second dorsal fin that has 15 to 17 rays; and, their pectoral fins form a cone which they utilize to elevate the anterior portion of their body when at rest. Their mouth is large and extends well beyond the eyes. They have 7 to 9 gill rakers. Their body is covered with minute scales. They do not have a lateral line.
The Arrow Goby is a demersal species that is found in both marine and brackish waters over sand and mud substrate in estuaries, lagoons and tidal sloughs at depths up to 45 m (150 feet). They can be found in very large numbers in small tidal pools. They utilize clam, shrimp and worm burrows for protection and during low tide episodes with one burrow housing up to 15 fish. They reach a maximum of 6.4 cm (2.5 inches) in length with the females being larger than the males with longer life-spans. They feed on algae, diatoms, eggs and tintinnids. They have a symbiotic relationship with Crabs whereby they place large food items near crabs which are torn into smaller pieces by the crab. In turn they are preyed upon by various Greenlings, Rockfish, Sculpins and Terns. Reproduction occurs as protogynous hermaphrodites with the females changing to males at mid-life; each female releasing 50 to 1,100 eggs multiple times per year into the water column and does not build a nest or care for the young. They have life-spans of up to three years. The Arrow Goby 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 Arrow Goby is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found only from Punta Abreojos, Baja California Sur, northward along the central and northwest coasts of Baja and within the northern portions of the Sea of Cortez.
The Arrow Goby, due its very long slender body profile and large mouth, it is a straightforward identification that is not easily confused with any other species.
From a conservation perspective the Arrow Goby has not been formally evaluated. They are small in stature and are of little interest to most. They can be found on occasion in public aquarium.