Oh My! Biology

Get to know some of the inhabitants of Indian Island. 
(To download printable "creature posters" use attachment below.)

What seahorse lives in Eastsound?


The bay pipefish (Syngnathus leptorhynchus) is an emerald-green native seahorse of the Salish Sea, and hundreds of them visit Indian Island every summer to mate and raise their young.  Like other seahorses, the female pipefish places her eggs in the brood pouch of the male, who carries them until they hatch.  (See video of a pipefish giving birth below!)  He then protects the tiny young until they are large enough to fend for themselves.  Pipefish are designed to live and hunt in eelgrass, and they can grow to 18 inches!  

pipefish giving birth

What fish grunts like a pig?


The grunt sculpin (Rhamphocottus richardsonii) is small (3 inches) and strange: not a true sculpin at all, it walks on its pectoral fins and sleeps in crevices or old empty barnacle shells.  If handled, grunt sculpins can grunt or bark their distress.  Grunt sculpins live alone, except to mate, but they are hardly romantic.  The female chases a male into a crevice and won’t release him until he has fertilized her eggs!  Grunt sculpins are sometimes seen foraging in the eelgrass meadows at Indian Island.

What fish has brass buttons?


The midshipman (Poricthys notatus) is aptly named for the neat rows of “buttons” on its golden underside and its purplish-blue back—like an old Navy overcoat.  An often-seen resident of the eelgrass at Indian Island, the midshipman is a member of the toadfish family and its brass buttons are more than mere ornament: each is a tiny phosphorescent lamp that attracts prey when the midshipman hunts, typically at night.  To attract mates midshipmen hum in chorus … so loud that they can be heard by people in shoreline homes! 

What starfish is always in the pink?


Often two feet in diamter, the short-spined sea star (Pisaster brevispinus) is one of the largest starfish found on the Eastsound waterfront. It forages in the eelgrass meadows for clams and snails, using an eye spot at the tip of each arm to find its way around.  Like many other starfish, it can regenerate another whole animal from a piece of an arm and a little bit of its central disk.  Unlike most of the starfish found around Indian Island, which can vary in color from red or orange to brown, blue and purple, the short- spined sea star is always pink. 

Don’t suck on this lemon!


The largest sea slug on the Eastsound waterfront is the sea lemon (Peltodoris nobilis), which can be the size of a real lemon.  Sea lemons move slowly over the rocks in the intertidal zone, like the snails with which they are related.  Sea slugs (nudibranchs) are mollusks that lack shells and have exposed gills; they defend themselves with toxic chemicals in their skin. Sea lemons graze on sponges, and in spring they lay, on the rocks, large coiled egg ribbons that look like flabby yellow or beige roses.  

Autumn water dancers

  hooded nudibranch                             egg ribbons                           

While most of our sea slugs are, 

well, slug-like, and crawl along on rocks, the hooded nudibranch (Melibe leonina) is a swimmer all its life, writhing rhythmically in the water.  Thousands of these animals appear around Indian Island in September to mate, and many of them spend the winter near Eastsound, using their hood-like cowl to trap and eat small swimming crustaceans.  The hooded nudibranch can also swallow and enslave algal cells, making it temporarily solar powered!  Paddle-like cerata on this animal facilitate oxygen uptake. 

Master of disguise!

This small, spindly decorator crab (Oregonia gracilis) is easy to miss, hiding in a mess of eelgrass or seaweed. While it scavenges for small animals and carrion to eat, the decorator occasionally picks up a little hydroid, or a bit of seaweed in its delicate claws and latches it onto tiny hooks on its own carapace or legs. As it grows to adult size of just a few inches, the decorator becomes a walking miniature garden.  When it is not moving, it's perfectly camouflaged.  This helps it avoid fish that find these crabs delicious and defenseless! 

Dining al fresco

    Pisaster Brevispinus by Kwiaht  
a sea star's mouth is located on the underside of its body, on its central disk

Did you know that sea stars digest their food outside their bodies?  Many species of sea stars feed on shellfish by expelling their stomachs through their mouths, digesting their prey inside its shell and then pulling their stomachs back in when they're finished.  Have you ever seen a sea star perched on its tip- toes?  More than likely it was in the middle of this unusual feeding behavior. 

Speed demons

Pycnopodia helianthoides by Kwiaht                              

If you are lucky enough to visit Indian Island during a low tide, you just might see a sunflower star (Pycnopodia helianthoides).  These creatures are large, up to 40 inches across with up to 24 arms, 
and have bright orange, soft bodies.  While these critters may seem docile and benign, looks can be 
deceiving.  Sunflower stars are the fastest of all the sea stars.  Propelled by their 15,000 tube feet, they
can travel up to 40 inches (1 m) per minute.  They are also fairly indiscriminate feeders, preying on everything from snails and urchins to sea cucumbers.  The sunflower star has the ability to open its 
mouth wide, ingesting large prey.  Sunflower stars can, for example, eat an entire sea urchin whole, 
digest it, then spit out its skeleton.  On the west side of Orcas Island, one hungry sunflower star was observed pursuing on injured seagull! 


Don't panic!

An echinoderm, the giant California sea cucumber.      

Several types of sea cucumbers live in the waters of Fishing Bay, around Indian Island.  One of the most striking is the California sea cucumber (Parastichopus californicus), a long, bright red, vibrant creature covered with orange spikes.  These gentle filter feeders lumber peacefully through the inter-tidal zone, dining on detritus.  However, when faced with a predator, this creature quickly sheds its calm demeanor.  The sea cucumber's primary defense strategy involves eviscerating its guts and fleeing, hoping that the pursuing creature will be distracted, thereby allowing the cucumber to flee to safety.  Luckily (for the sea cucumber), the shed organs restore themselves in time.  
Andria Hagstrom,
May 14, 2010, 1:13 PM