This photo made my day so I had to pass it along. According to a story on Telegraph.co.uk, the photo was taken by marine biologist Rory Moore during a dive off the Strait of Gibraltar.

It was Moore’s impression that this pod of pilot whales had little contact with humans and were extra curious. The whales approached the divers blowing bubbles, barking and checking out their reflections in the camera lens. But pilot whales do have teeth and are wild animals so Moore was careful to keep his distance during displays of aggressive behavior.

Pilot whales are members of the dolphin family Delphinidae and similar to dolphins the pilot whale smile is slightly permanent. Although I compared this photo to other pilot whale photos online and this pilot whale does seem to have more than the average permanent grin.

There are actually two types of pilot whales, short-finned and long-finned and it’s pretty tough to tell the difference unless you’re a pilot whale watching pro. The key difference is the size of the pectoral and dorsal fins, both are larger on the long-finned pilot whale. Based on other photos that ran of the same pod of whales on Dailymail.co.uk, it looks like a group of long-finned pilot whales. The pectoral fins have a nice size and heft to them.

Male pilot whales can reach more than 20 feet in length and average six more feet in length than females. There’s that sexual dimorphism again, a visible difference between males and females of the same species. Males weigh up to 5,000 pounds and gain much of that weight by dining on squid.

One fun/crazy fact I came across in the Encyclopedia of Marine Mammals is the gestation time for short-finned pilot whales is 15 to 16 months! Yikes, that’s not something to smile about.