The nurse shark is the boss
If we were to specify a hierarchy among the sharks using our instinct we would probably always go by the size and impression of the teeth. But it’s the harmless nurse shark, usually to be found lying sociably and peacefully on the ground, which ranks above the other shark species!
In the harbour quite a few nurse sharks, some almost 3 meters long, had already gathered at the boat to catch any fish waste. It's difficult to get into a dangerous situation with a nurse shark, but if it really bites, it will not let go again. Erich told us of accidents involving nurse sharks, where the person was taken out of the water together with the shark before it let go! Nurse sharks have only very small teeth, but incredible suction strength. They feed on bottom-dwelling invertebrates which they can simply suck out of their hiding places.
On the third day of the shark workshop, a nurse shark of about 2.5 m joined us. It circled the reef sharks at the feed basket a few times and then proceeded to eat. All the Caribbean reef sharks (Carcharhinus perezii) retreated instantly, leaving the feed basket to the peaceful creature.
When the nurse shark arrives, all the other sharks retreat! Since the movie camera was mounted on the photo camera, I apologize for the portrait format moments.
After the nurse shark had sucked its food out of the basket in peace, it swam another round and then came directly towards me. My underwater flash had sparked its curiosity.
My Hartenberger underwater flash has a power of 250 watt seconds and presumably also correspondingly large capacitors. The electromagnetic fields emanating from it were very interesting for all the sharks, not only for the nurse shark. It swam directly towards me with its snout heading to the flash, which was 30 cm in front of my face. I slowly pivoted round and the nurse shark followed the flash. Its fins were almost pushing my goggles off my face. When it realized that the flash was not interesting after all, it let go, swam briefly against my flippers and decided they were boring as well. It stayed with us, but did not return to my flash or my fins a second time.
Nurse shark falls for my flash and my fins
The reef sharks were joined by a nurse shark, which swam directly to my underwater flash to examine it.