Gobius gasteveni
A rare, tiny goby found almost exclusively around Brittany, France, in cool 10-16C water. Here's how to spot one.
At around 8 cm, this is a small, slender bottom-dwelling fish with the typical goby build: elongated body, blunt head, and large eyes set high on the skull. Colouring runs to muted mottled browns and greys that blend into rocky and gravel seabeds, without any bright or high-contrast markings to key on. Look for it perched motionless on the substrate rather than swimming in open water, propped on its fused pelvic fins the way gobies do.
Divers log this goby resting still on rock or gravel bottoms rather than out swimming, typical of small bottom-dwelling gobies that rely on staying put and blending in. It's logged as rare at almost every site where it turns up, so sightings tend to be a slow, close look at the substrate rather than an obvious encounter. It shows no particular reaction to divers beyond the usual goby habit of holding position until approached too closely.
Its rarity in the data isn't necessarily about scarcity in the water so much as how easy a small, drab, motionless bottom fish is to overlook entirely, which makes confirmed sightings a real test of a diver's eye for detail.
Sightings don't show a clear seasonal pattern, so treat it as a year-round possibility in Brittany's cool water, which sits naturally in the 10 to 16C range this species favours.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
This one is a Brittany speciality: every logged sighting so far comes from sites along the French Brittany coast, with no confirmed records elsewhere. If you're diving cool Atlantic water in this region, keep an eye on rocky and gravelly bottoms rather than open reef.
Mapping where Steven's Goby is logged…
Nearly all logged sightings come from Brittany, France, making it the one confirmed region for this species. Rocky and gravel seabeds are where divers have found it.
There's no detected seasonal pattern, so it's considered a year-round find in Brittany's cool coastal water, which typically sits between 10 and 16C.
Look for a small, roughly 8 cm goby with a mottled brown-grey body resting still on rock or gravel rather than swimming. It lacks bold markings, so its low-key camouflage and stationary perch are the main clues.
They stay small, reaching around 8 cm in length, consistent with most bottom-dwelling gobies in cool Atlantic water.
No. It's a small, harmless bottom-dweller with no risk to divers.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Slender Goby
803 sites
