Remoras are primarily
tropical open-ocean dwellers, occasionally found in
temperate or coastal waters if they have attached to large fish that have wandered into these areas. In the mid-
Atlantic, spawning usually takes place in June and July; in the
Mediterranean, in August and September. The sucking disc begins to show when the young fish are about 1 centimetre long. When the remora reaches about 3 centimetres, the disc is fully formed and the remora is then able to hitch a ride. The remora's lower jaw projects beyond the upper, and there is no
swim bladder.
Some remoras associate primarily with specific host species. Remoras are commonly found attached to
sharks,
manta rays,
whales,
turtles, and
dugong (hence the common names
sharksucker and
whalesucker). Smaller remoras also fasten onto fish like
tuna and
swordfish, and some small remoras travel in the mouths or gills of large
manta rays,
ocean sunfish,
swordfish, and
sailfish.
