Tag Archives: cleaner wrasse

Little cleaner wrasses offer spa experience to other fish

Published August 20, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
A cleaner wrass with an island jack customer. ©2016 Susan Scott

A cleaner wrass with an island jack customer. ©2016 Susan Scott

Last week, in about 7 feet of water, I swam over a reef wall and found myself in the middle of a dozen jacks, a new species to me, each bearing yellow, dashiki marks on their sides.

Having a monster in their midst caused the fish to dart up, down and around, but surprisingly they didn’t flee. When I backed off, I saw why. The jacks were waiting for a turn at the spa.

Reef spas are run by narrow, 4-inch-long fish called cleaner wrasses. A variety of fish pick goodies off other fish for food, but only the cleaner wrasse sets up a service station. It’s a one-stop shop for pest removal, wound debridement and massage.

The wrasses work alone, in pairs or in teams up to five. To advertise their business, the little fish bob their neonlike bodies up and down. The front half of the fish’s body is a glowing yellow, and the rear half is purple with lavender edges. A black stripe runs from eye to tail, accentuating the fish’s bright colors.

You can’t tell a male from a female cleaner wrasse by color, but you can tell a juvenile from an adult because young cleaners are nearly all black. The kids get their grown-up colors early on, when they’re only about an inch and a half long. If a cranky adult chases away a little wrasse sporting its new colors, the youngster can change back to black and safely move to a friendlier neighborhood.

When I first learned about cleaner wrasses while studying biology at the University of Hawaii, the fact that Hawaii hosts an endemic species was so emphasized that I thought the little service fish was a Hawaii-only phenomenon. Later, though, I saw similar cleaner wrasses on just about every reef I visited in the tropical Pacific. The Hawaiian cleaner wrasse, it turns out, is only one of five species in the Indian and Pacific oceans. Ours, though, is the prettiest.

Not all fish that visit wrasse cleaning stations have parasites or dead skin that’s bugging them. Researchers believe that the sensation of the wrasses’ fins wiggling against the skin feels good to their clients. Big fish sometimes come just for a back rub.

The jacks I saw lining up for a rubdown are a rather rare species here. Called island jacks, yellowspot trevally or ulua, these silvery fish with yellow side spots usually school in deep water but sometimes come inshore. They grow to about 28 inches.

I’d never before seen a school of island jacks or watched any jack hold perfectly still with mouth and gill covers open while a cleaner wrasse worked it over. That’s why I don’t mind snorkeling in the same seemingly unremarkable places over and over. I never know what I’m going to get, and it’s always an adventure.

Cleaner wrasses exfoliate, pick parasites from others

Published September 30, 2013 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2013 Susan Scott

A striped cleaner wrasse in Raiatea nibbles on Susan Scott’s leg. ©2013 Susan Scott

I never imagined that having furry, shedding legs would provide me with a unusual marine animal experience, but that’s the fun of the ocean. You never know what’s going to happen.

One day, while snorkeling in about five feet of water, I stopped to photograph a clownfish in an anemone. I placed the tips of my fins on the seafloor rubble and held very still.

As I watched the clownfish through the viewfinder, I felt a tickle on my shin and then a painful little tug. A 4-inch-long cleaner wrasse was nibbling my skin and pulling my hairs. Apparently I had planted myself in the middle of a wrasse-cleaning station.

This was not an exceptionally bold fish. Cleaner wrasses are common reef fish that make their living picking off mucus, parasites and dead skin from fish, and apparently sometimes off people. The wrasses also eat growth from turtle shells, pick scraps from shark lips and clean the teeth of open-mouthed moray eels.

Fish book photos often show cleaner wrasses poking their pointy snouts inside the gills of grateful-looking fish.

The wrasses’ customers seem to love the service, flocking to the wrasse cleaning stations usually held in an overhang or indentation of the reef.

Often two, and sometimes up to five, cleaner wrasses work a station together. The customers wait patiently, sometimes even lining up one behind the other. When it’s their turn, the fish assume postures that seems to say, “A little higher and to the left, please. Ah, yes, that’s it.”

The cleaner wrasse gets a meal, and the fish gets a spa treatment.

Hawaii hosts one endemic cleaner wrasse, a yellow and purple beauty seen commonly on our reefs.

wrasse

Hawaiian Cleaner Wrasse, bottom center. Courtesy Scott R. Davis

The South Pacific hosts five species.

All are about 4 inches long, and like all wrasses, they change sex.

Cleaner wrasses begin life as females, and between 1 and 3 years old, depending on the need in the community, they change to males. Each male in a vicinity spawns with up to 12 females.

I’ve been home only a day, and already I’m reminiscing fondly about my two-month voyage through the Society Islands. It seems that nearly everything I do reminds me of some part of that trip.

Even shaving my legs.


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

©2013 Susan Scott