Weather phenomena may be behind the discovery of two rare fish in Bermuda last weekend.

Two dead sunfish, or slender mola (scientifically known as Ranzania laevis), which are not normally seen north of Mexico, were discovered on Sunday at separate locations in the East End.

One was found on the South Shore of Coopers Island in St. David's by Judith Clee while Kyle and Chris Smith found a second the same day at Clearwater Beach.

Both were turned over to the Natural History Museum at the Bermuda Aquarium, Museum and Zoo (BAMZ).

Curator Dr. Wolfgang Sterrer said these smaller relatives of the ocean sunfish have only been seen in Bermuda once previously.

While that specimen was only partially whole, the two found on Sunday are in very good condition and Dr. Sterrer said BAMZ would be dissecting the fish to see what can be learned about one of the ocean's most mysterious inhabitants.

"Very little is known about these fish or about their diet," Dr. Sterrer told The Royal Gazette.

The fish have a unique appearance with a tail that looks almost like it has been chopped off, he said.

They also have a permanently open mouth which is believed to facilitate eating jellyfish in the larger relative.

While the ocean sunfish (or Mola mola) can grow to up to two tonnes in weight and is thought to be the world's largest bony fish, the smaller cousins found on Sunday grow to roughly two feet, Dr. Sterrer said.

Both fish are known to float lying flat on their sides on the ocean's surface which has earned them the popular name 'sunfish'.

Scientists think this peculiar love of sunbathing may be undertaken for thermo-regulation purposes but the particulars of the mola's habits are still largely a mystery.

What brought the fish to Bermuda, and led to their untimely demise, may be the same phenomena that has seen large ocean squid wash up on the Island shores, Dr. Sterrer suggested.

"It is very interesting that two would show up all of a sudden," Dr. Sterrer said. "We might be seeing a similar pattern stranding the otherwise open ocean creatures as has been seen with the large ocean squid in recent years.

"It tends to happen in the early part of the year, the first three months or so, and they are usually found after what seems to be a cold spell after a warmer period."

With this weekend's low temperatures of 54 degrees Fahrenheit following a humid and warm period last week, the arrival of the rare molas seems to fit the pattern.

The opportunity to study the rare fish is a welcome one for BAMZ.

"Like many open ocean creatures they are so elusive that very little is known about their habits," Dr. Sterrer said. "We're very excited to have two on the same day."