Granseola - Maja squinado
We’ve been trying to film it for a long time, but unfortunately it’s getting harder and harder to find. It’s the European spider crab, Maja squinado (spiny spider crab, or spinous spider crab). This crustacean of the Majidae family was very common about thirty years ago, and specimens like the one we see in the video were very easy to find in the intertidal tidal pools, provided they had plenty of rocks to hide in and algae to grow on their backs to camouflage them from predators. As you can see from the video, they now find their ideal habitat on rocky coasts at depths of a few meters, avoiding tidal zones that are probably less safe, partly due to human presence.
Spider crab (Maja squinado Herbst, 1788), commonly called granséola, is a decapod crustacean of the Majidae family.
Description
Orange-brown carapace, sometimes orange-red, with numerous brown-edged spines. Long, thin legs, adapted for navigating the sandy seabed. Small front claws, with a lighter tip, end jointed arms, the same thickness as the legs.
The name Granséola comes from the Venetian words granso (crab) and séola (onion).
Biology
This crustacean lives on rocky marine substrates. Its essential defense is its exceptional camouflage, which allows it to hide perfectly among the algae and colorful rocks of the seabed. The spider crab periodically sheds its shell through a moult. During this period, the animal is defenseless and vulnerable to any attack. When the old shell breaks, the animal is covered by a very soft covering and, therefore, must quickly find a safe place to hide. It feeds primarily on algae, bivalves, insect larvae, worms, and small fish trapped in nets and hollows. It can reproduce up to four times a year.
Distribution
Eastern Atlantic Ocean, from Ireland to Guinea, Mediterranean Sea.
In Italian seas, this crab, weighing about 500 g, lives at depths of about 100 m but can reach depths of thousands of meters, especially in the seas of Sardinia. It can also be found at shallow depths in the northern Adriatic. It is typically covered with sea lettuce for better camouflage on the seabed.
https://it.wikipedia.org/wiki/Maja_squinado
https://en.wikipedia.org/wiki/Maja_squinado
Gallery
Video Gallery