Mediterranean · Volume 3 · Species guide
Small-Spotted Catshark
Even before hatching, the small-spotted catshark already perceives the invisible
Scyliorhinus canicula - SCYLIORHINIDAE
Natural-history notes
Species at a glance
Observation
Where to look:
Original natural-history story
The story of the species
On a sandy bottom, it can seem almost motionless, as if this small spotted shark simply lets divers pass. Yet the small-spotted catshark perceives a world that escapes us: it detects weak electrical fields and can locate prey hidden under the sand.
If you encounter it resting in broad daylight, its calm is deceptive: it is mainly active at night. At Lough Hyne in Ireland, females were even observed grouped together during the day in shelters then moving to deeper waters at night, a behavior linked by researchers to avoidance of repeated solicitations from males.
Its reproduction holds another surprise: in a study of 13 females, the offspring of 12 of them had multiple fathers. Then comes the capsule.
During development, it opens partially to increase water renewal when the embryo's oxygen needs increase. And even before hatching, it already possesses its electrical sense: when experimentally exposed to a stimulus, it can interrupt its ventilation and freeze, a reaction interpreted as a possible anti-predator response.
Long before its first free swim, the small-spotted catshark already perceives an electrical world invisible to us.
Continue the encounter
The sticker from your encounter
Secrets of the Sand — 5-sticker pack. Greater Weever, Stargazer, Marbled Electric Ray, Blonde Ray, Small-Spotted Catshark.
Stickers and logbook are sold separately. Observe marine life without touching or disturbing it.