Videos and notes by marine biologist Dr. Alan Deidun c  
 

01 Jellyfish

Jellyfish are among the best known members of the plankton family, which includes all marine species that drift along with water currents. While most think of Plankton as microscopic, some plankton, such as jellyfish, are easily visible to the naked eye.

Seen here is the fried egg jellyfish, which normally appears in Maltese coastal waters during late summer. Certain species of fish, such as mackerel, seek refuge amongst jellyfish tentacles where they are less vulnerable to predators.

 
 

02 Bristle Worm

Polychaetes, or as they are more commonly known, bristle worms, are amongst the most ubiquitous of underwater creatures, exhibiting a mesmerizing array of forms and habits. Most polychaetes, including the bearded fireworm shown here, are scavengers and will consume practically any organic material which comes their way. The fireworm owes its name to the burning sensation it imparts to any reckless diver that might stumbles upon its bristles, which detach and penetrate the skin to release a venomous toxin.

 
 

03 Fan Worm

Fan worms are a class of polychaetes with tentacles modified for straining small planktonic organisms out of the water. The tentacles are rapidly retreated upon the slightest vibration in the water.

 
 

04 Moray Eel

The moray eel prefers crevices in rock which provide excellent shelter. Despite its ferocious appearance, it avoids humans and uses its sharp teeth to prey on small fish only.

 
 

05 Bluefin Tuna

The term tuna is vague since together with the mackerels, tuna species includes over 50 species of bony fish. What you see here is the Atlantic Bluefin Tuna, which is the species most commonly found in the Mediterranean waters. Unlike most other fish, the Atlantic Bluefin Tuna is warm-blooded.

This species of tuna is truly a giant and can grow up to 4 meters long and weigh up to 3 quarters of a tonne. However this fish is amazingly fast for its size and can swim up to 90 km per hour. The full life span of a Bluefin is approximately 30 years and they reach maturity around the age of 8.