Head to head
Rock Goby vs Shanny
Rock Goby
VS Shanny
The rock goby and the shanny are two small, mottled brown fish that share the rock pools of the north-eastern Atlantic, and they are often confused by those who find them under stones.
| Rock Goby | Shanny | |
|---|---|---|
| Scientific name | Gobius paganellus | Lipophrys pholis |
| Group | A goby, with its pelvic fins joined into a sucker disc | A blenny, with a smooth, slimy, scaleless body |
| Appearance | A stout, mottled brown body, a broad head, and a pale edge to the first dorsal fin | A mottled olive-brown body that gives camouflage among rocks and weed |
| Size | Usually around 10 to 12 cm long | Usually around 10 to 16 cm long |
| Out of the water | Clings to rock in surge, currents, and when the tide is out | Survives out of water for hours at low tide by hiding under damp weed and breathing through its skin |
| Coping and memory | Copes with the changes in temperature and salinity in rock pools | Finds its way back to its own rock pool after being moved some distance away, apparently using a memory of the shore |
| Diet | Carnivore, eating small crustaceans, worms, and molluscs | Omnivore, eating algae, barnacles, small crustaceans, and other small animals in rock pools |
| Conservation status | Least Concern, from the British Isles to Morocco and the Mediterranean | Least Concern, widespread and abundant from Norway to Morocco |
Rock Goby vs Shanny: common questions
How can you tell a goby from a blenny?
The goby has its pelvic fins joined into a sucker disc, while the blenny, such as the shanny, has a smooth, scaleless body and separate pelvic fins.
Which one survives out of water?
The shanny, which can survive for hours at low tide by hiding under damp weed and breathing through its skin.
Do both guard their eggs?
Yes, in both species the male guards the eggs, which are laid in a crevice or under a stone.