Tag Archives: crab

Naming sea creatures sometimes had odd results

Published March 7, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
 A ghost crab has a turtle hatchling caught in its pincers. The tiny turtles must pass the crabs to make it to the ocean. ©2016 Susan Scott

A ghost crab has a turtle hatchling caught in its pincers. The tiny turtles must pass the crabs to make it to the ocean. ©2016 Susan Scott

In my Feb. 22 column, I wondered about the origin of the odd fish name “Moorish idol.” About that, Honolulu reader Ned Conklin emailed an excerpt from a 2007 book, “When Languages Die,” by K. David Harrison (Oxford University Press).

The author writes that early European explorers and naturalists disregarded native names for plants and animals, and instead gave them English names relating to something the species reminded them of back home. For instance, on Capt. James Cook’s third voyage, 1776-80, the naturalist aboard named a damselfish with stripes a sergeant, because a British sergeant’s uniform had stripes.

Scientists later learned that the sergeant fish was actually three species. Fish namers stuck with the historic term “sergeant” but added other words to tell the species apart. Hawaii’s endemic sergeant became the Hawaiian sergeant. The damselfish with wider and longer stripes and a wide range is the Indo-Pacific sergeant. And the fish with stripes that lighten and darken, and that has a black spot on its rear, was named the blackspot sergeant.

As to the Moorish idol, Harrison writes, “A fish with a dark-colored face spotted by Capt. Cook’s crew off Hawaii received the exotic name ‘Moorish idol.’”

Another reader, Utah biologist Robert Schmidt, emailed about my Feb. 8 column on ghost crabs. Robert thought he read that ghost crabs blinded or maimed turtle hatchlings before pulling them into their burrows, thereby preventing the hatchlings from escaping. He can’t find a reference to these behaviors and asked, “Do you know anything about this?”

Only what I saw. On Tern Island I watched turtle hatchlings run the ghost crab gauntlet in their race to the ocean. If the crab got hold of only one flipper, the turtle usually got away. But when the crab got a flipper in each of its two pincers the turtle couldn’t escape.

I rescued several hatchlings before they got dragged down a crab hole, and they ran away seemingly uninjured. But I got there too late for some. Lifting one turtle from a crab hole entrance, I found its head missing and the entire body hollowed out. Efficient, those crabs.

Besides being occasional crab food, turtle hatchlings are pupu for seabirds from above and fish from below. Only about 1 hatched turtle in 1,000 makes it to adulthood.

On the bright side, healthy adult turtles are common in Oahu waters, as are ghost crabs performing their daily beach cleanups and sand aeration.

Ned and Robert, thanks for the interesting emails. But I still don’t understand why a naturalist linked the term “Moorish” with “idol.” An exotic name indeed.

7-11 crab gets its name from its array of spots

Published September 15, 2014 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2014 Susan Scott

This 7-11 crab was found in a Waia­lua tide pool. The crab is named for its spots — 11 total, with seven in front and on top, and four in back. ©2014 Susan Scott

I recently received an email with the subject “Crab on V-land beach.” (V-land, or Velzyland, is a North Shore surf spot.) Reader Bill Quinlan wrote, “I have attached two photos of a dead crab we found this afternoon. A lady we showed the crab to said she was from Kauai and they call that type of crab a 7-11 crab. She did not explain why.”

Oahu people call them 7-11 crabs, too. The striking species ranges throughout the Indian and Pacific Oceans on reefs from tide pools to 50 or so feet deep. Other names are spotted reef crab and dark finger coral crab. In Hawaii, though, and for many people around the world, it’s a 7-11 crab.

A common story about the unusual name is that it’s a reference to the crab’s maroon spots. Although some individuals have more, most crabs have seven spots across the shell’s front and top, and four across the lower back, totaling 11.

This logic would make it a 7-4 crab, but the words “seven-11” have more of a ring. A convenience store chain called Tot’m liked the rhyming words, as well.

In 1946 the name was changed to 7-Eleven to reflect its long (for the ’40s) operating hours, 7 a.m. to 11 p.m.

Two days after Bill’s email, I received another 7-11 crab email from my friend Mary. “This morning I found the remnants of a huge 7-11 crab on the reef at Ala Moana. His shell was about 8 inches across. First one I ever saw, living or dead. I understand from other locals there that about two years ago a lot of juveniles washed ashore. What an interesting world!”

It sure is. For unknown reasons, in July 2012 thousands of blueberry-size creatures washed ashore on Oahu. Being in their larval stage, the creatures didn’t look much like adult 7-11 crabs, but that was an expert’s conclusion. Check out the baby crabs at bit.ly/1CKYqFA.

I also found a 7-11 crab, but it was alive and well in a Waia­lua tide pool. After I took this picture, I put the little crab back in its pool to grow up and make more crabs. In Singapore the species is considered threatened due to pollution and over-collecting.

Seven-11 crabs grow to about 6 inches across, so the crab Mary found was as big as they get. She took it home to let the ants clean it outdoors before giving it a place of honor in the house.

Bill considered his crab a gem, too. “My wife, Rita, and I have been dive buddies for almost 40 years and have dived in numerous countries,” he wrote. “We both feel this is the most special crab we have ever seen. A graphic designer couldn’t come up with a design anywhere close to as good.”

I agree. A certain convenience store would do well to make this crab its logo.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2014 Susan Scott