Tag Archives: crinoid

Colorful reef habitats offer shelter from a storm

Published February 18, 2017 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2017 Susan Scott

Feather stars are related to starfish. Standing a foot tall, they resemble a bouquet of flexible twigs. ©2017 Susan Scott

KOROR, PALAU >> My week in Palau was not what my eight snorkeling companions and I had pictured. Winter is the dry season here, where usually the days are sunny, the water is clear and jumping off the boat is a relief from the tropical heat. But Mother Nature doesn’t care if visitors have only one week to enjoy paradise. An unseasonal storm front moved over Palau and stalled there.

Blustery squalls drove needlelike rain into our faces, preventing the boat from going to reefs exposed to the strong wind and big waves. Not ones to give up, our resourceful guide and driver found two previously unexplored reefs in bays protected from the wind. Because they were surprise discoveries, they were also protected from other tour boats. The areas were ours alone to enjoy.

The first new reef Robin and Matty found we named Oceanic Coral Garden, a place deserving of the name garden. Sponges in brilliant red, yellow, orange and blue squeezed between, and plastered themselves on, a multitude of coral heads.

Sponges look stuck in one place for life, but these filter feeders can walk. When it needs to move to a better food gathering place in the current, a sponge absorbs cells from one side of the body and deposits them on the other.

Sponges’ gradual way of relocating makes snails look like NASCAR racers. But sponge colors, shapes and the fact that they get around at all made sponges a group favorite.

Crinoid Cove is the name we gave our other private place. The peaks and valleys there were of such coral diversity, it looked as if a bunch of patchwork quilts had been draped over tall tables and low chairs. And on top of nearly each rise perched a crinoid, also known as a feather star.

A flamboyant cousin of starfish, a feather star looks like a bouquet of flexible twigs, called arms, standing about a foot tall. On both sides of each twig extend sticky tube feet spaced like the teeth of a comb.

When a piece of animal plankton drifts into a crinoid’s combs, the gluey feet trap it. The animal then covers the gummy meal with slippery mucus and slides it, with beating hairs, down the middle of the arm’s shaft to the central mouth.

Feather stars hang onto their hilltops with rootlike “feet” and are easily knocked off their perch. No worries. A feather star can swim by curling and flapping those twiglike arms and once again be king of the hill.

Crinoids are two-toned, the base of the arms often black with tube feet of green, orange, yellow or white. Not common, feather stars are a sight to behold and along with the sponges were a group favorite.

Bad weather might spoil a trip but for some, but it didn’t for us. Because of the persistent storms, our wonderful Palauan guides found and shared two of their country’s secret gardens.

Next stop: Yap.

A snorkeler adrift in Palau finds underwater rewards

Published November 16, 2015 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2015 Susan Scott

A crinoid walks along the sea-bed in the waters of Palau. ©2015 Susan Scott

A crinoid walks along the sea-bed in the waters of Palau. ©2015 Susan Scott

PALAU >> In some of my favorite snorkeling spots here in Palau, I don’t have to stroke my arms or even move my fins to see vast stretches of coral reef. With Palau’s tidal range of 6 to 7 feet, and two high and two low tides daily, the current along the edges of deep channels is sometimes strong enough that we snorkelers have little choice of where to go. There’s nothing to do then but relax and let the ocean have its way.

Drifting effortlessly above colorful coral reefs is fantastic, but it’s hard to get a good look at a particular organism. By the time I turn around and swim up-current, I’ve often lost sight of what I wanted to look at. Also, there are no handholds to help a person steady a camera. Touching coral is a strict no-no, and it’s almost all coral.

But drift snorkeling has a big plus. Moving water offers free delivery to suspension feeders such as sea fans, soft corals and other wonders. Among those wonders are feather stars, also known as crinoids.

Crinoids (not found in Hawaii) are starfish and sea urchin relatives but have a shape and lifestyle all their own.

Crinoids get to touch the coral. The black, green and orange creatures stand in the open on coral heads, positioning their multiple feathery appendages in the current.

Tiny tube feet tipped with sticky mucus stick out from both sides of each arm. When the moving water brings tiny plants and animals to the crinoid, they get stuck in its glue.

This starts the crinoid’s ingestion assembly line. The outer tube feet flick the food to inner tube feet that cover it in slippery mucus and then deposit the catch in a groove at the center of each arm. There tiny hairs act like conveyor belts, transporting the meal to the creature’s mouth at the center.

Although they can walk and even swim, most crinoids find a spot they like and park there. Because crinoids have rootlike feet, a walking feather star looks a mutant flower searching for a sunnier spot.

Compared with 500 million years ago when they covered the ocean floors, crinoids are rare today. But their fossils are not. Among other places, they’re abundant in the Midwest. Missouri’s state fossil is the crinoid.

Drift snorkeling here isn’t scary because at the end of the channels, the water spreads out and the current stops. In addition, the boat goes with you. Palau’s boat drivers follow snorkelers and divers, so you can get out of the water when you like.

I’m soon starting my second Palau tour as a naturalist for the Oceanic Society, and even though I don’t know what I’ll see, I know one thing for sure. I will go with the flow.


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

©2015 Susan Scott