Arrow goby • Clevelandia ios
Identification
This light grey translucent fish gets to 6.4 cm long. Its two dorsal fins: the first (anterior) is shorter with 4-5 spines, while the second (posterior) is longer with 15-17 soft rays (most posterior dorsal fin). Its anal fin is about the same length as the second dorsal fin, with 14-17 soft rays, and its caudal (tail) fin is rounded like other gobies. Its pectoral fins are fused into a cone that the goby uses to prop itself up. This fish has tiny scales, and the edges of its mouth extends behind the eyes. Its dorsal fins are dotted with short dash-like stripes, and its body colour is usually tan to grey with darker speckled patterns.
Habitat & Range
The arrow goby ranges from Rivers Inlet, British Columbia to Baja California, Mexico. It inhabits sanddy- or muddy-bottomed tidal flats, estuaries, lagoons, and tidal sloughs, where it feeds on diatoms and algae, as well as the eggs and young of crustaceans. This species does not build dens, but instead lives in burrows created and occupied by clams, shrimps, and worms. Some of the invertebrates it lives with include ghost shrimp (Neotrypaea californiensis), mud shrimp (Upogebia pugettensis), and fat innkeeper worms (Urechis caupo).
Similar Species
There are two other gobies in British Columbia; the bay goby (Lepidogobius lepidus) and the blackeye goby (Rhinogobiops nicholsii). Neither have the arrow goby's large mouth which extends past its eyes. The blackeye goby is distinguished by its dark eyes, black tip on its first dorsal fin, and large scales.
Intriguing Info
Arrow gobies are unusual in their family because they do not dig their own burrows or care for their young, which they disperse widely in the water column. They also have very interesting signalling to warn against predators and to attract mates: arching their backs and rolling to the side, they use their silvery underbelly to flash a signal to others of their species before diving into their dens. They perform a similar motion to attract mates, although they ‘jump’ along the tidal flats after every flash. Arrow Gobies are protogynous hermaphrodites, producing female gametes and then turning into males. They have also been observed bringing large food items to crustaceans to be ripped into smaller pieces.
iNaturalist
https://www.inaturalist.org/taxa/117564-Clevelandia-ios
This light grey translucent fish gets to 6.4 cm long. Its two dorsal fins: the first (anterior) is shorter with 4-5 spines, while the second (posterior) is longer with 15-17 soft rays (most posterior dorsal fin). Its anal fin is about the same length as the second dorsal fin, with 14-17 soft rays, and its caudal (tail) fin is rounded like other gobies. Its pectoral fins are fused into a cone that the goby uses to prop itself up. This fish has tiny scales, and the edges of its mouth extends behind the eyes. Its dorsal fins are dotted with short dash-like stripes, and its body colour is usually tan to grey with darker speckled patterns.
Habitat & Range
The arrow goby ranges from Rivers Inlet, British Columbia to Baja California, Mexico. It inhabits sanddy- or muddy-bottomed tidal flats, estuaries, lagoons, and tidal sloughs, where it feeds on diatoms and algae, as well as the eggs and young of crustaceans. This species does not build dens, but instead lives in burrows created and occupied by clams, shrimps, and worms. Some of the invertebrates it lives with include ghost shrimp (Neotrypaea californiensis), mud shrimp (Upogebia pugettensis), and fat innkeeper worms (Urechis caupo).
Similar Species
There are two other gobies in British Columbia; the bay goby (Lepidogobius lepidus) and the blackeye goby (Rhinogobiops nicholsii). Neither have the arrow goby's large mouth which extends past its eyes. The blackeye goby is distinguished by its dark eyes, black tip on its first dorsal fin, and large scales.
Intriguing Info
Arrow gobies are unusual in their family because they do not dig their own burrows or care for their young, which they disperse widely in the water column. They also have very interesting signalling to warn against predators and to attract mates: arching their backs and rolling to the side, they use their silvery underbelly to flash a signal to others of their species before diving into their dens. They perform a similar motion to attract mates, although they ‘jump’ along the tidal flats after every flash. Arrow Gobies are protogynous hermaphrodites, producing female gametes and then turning into males. They have also been observed bringing large food items to crustaceans to be ripped into smaller pieces.
iNaturalist
https://www.inaturalist.org/taxa/117564-Clevelandia-ios
References
Clevelandia ios (Jordan & Gilbert, 1882). In Froese, R. and Daniel, P. (Ed.). FishBase. Accessed 06/23/2014.
Arrow Goby, Clevelandia ios. (Jordan & Gilbert). In Lane, Edwin David and Hill, Cliff W. (Ed.) The Marine resources of Anaheim Bay. California Sacramento : State of California, Resources Agency, Dept. of Fish and Game. Accessed 06/23/2014.
Authors and editors of page
Andrew Sheriff, Kelly Fretwell, and Brian Starzomski (2014).
Clevelandia ios (Jordan & Gilbert, 1882). In Froese, R. and Daniel, P. (Ed.). FishBase. Accessed 06/23/2014.
Arrow Goby, Clevelandia ios. (Jordan & Gilbert). In Lane, Edwin David and Hill, Cliff W. (Ed.) The Marine resources of Anaheim Bay. California Sacramento : State of California, Resources Agency, Dept. of Fish and Game. Accessed 06/23/2014.
Authors and editors of page
Andrew Sheriff, Kelly Fretwell, and Brian Starzomski (2014).