Saturday, January 12, 2008

Rare Fish Part 2 - Ranzania laevis

Photo by Jacqueline Hernandez

An Update on the "rare" fish story in the Tribune.

According to Mike Trianni from Fish and Wildlife the large fish pulled from the beach in Chalan Kanoa last week was a Slender mola (Ranzania laevis) one of three species in the family Molidae or Sunfish.

The family Molidae has three distinct species. The Common Sunfish or Mola mola, the Sharp-tailed mola or Masturus lanceolatus and the Slender mola or Ranzania laevis.

These giant ocean sunfishes are some of Earth’s most fascinating yet mysterious creatures. As jelly-eating giants they hold the record for being the world’s heaviest bony fish and occupy a unique place in the open ocean web of life.

Of the three the Slender mola is the smallest and most colorful. They rarely get larger than a few feet while the common Mola mola averages about 6ft and 2000lbs with the largest recorded coming in at nearly 5000lbs!

The word mola comes from Latin and means milestone-in reference to these fishes' roundish shape. The common name "ocean sunfish" comes from the Mola mola's habit of lying atop the surface of the ocean appearing to sunbathe.

The Slender mola (Ranzania laevis) eat an assortment of crustacean, fish and molluscs including myctphid larvae, hyperiid amphipods, crab megalops, crab zoea and pteropods. Most feeding appears to take place within 150m (500 ft) of the surface. (Fitch, 1969)

All three species of sunfish are found in all tropical and temperate oceans. The slender mola is considered uncommon here in the Northern Mariana Islands.

Please visit the Ocean Sunfish dot org site for more information. Much of what is written here is adapted from this site.

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