False Bay: Species Descriptions
As a subsurface deposit feeder, the lugworm Abarenicola lives
in a J-shaped tube with its posterior end close to the surface. It produces
distinctive coiled fecal castings at the mouth of the burrow. Try the following
trick: poke a finger into a burrow hole, and see if water springs up out
of another hole, showing that the two holes are connected by a common burrow.
Digging under a few fecal castings will surely turn up a lugworm. The bright
red gills along the sides of this worm are in contrast to its dull brown
The tube of this worm can be seen throughout the sandy areas of False
Bay, but it is rare to find a complete specimen. Chaetopterid tubes may
reach as deep as 2 m, making it difficult to dig one out, although a quick
shovel full may turn up a portion of the anterior end. The body of the
chaetopterid is divided into three main sections. These animals are filter
feeders, using a unique mucous
bag to capture food particles.
Named for its deep red color, glycerid worms are found in most parts
of False Bay. Glycerids are long slender worms with what seem to be featureless
heads. When disturbed, however, you may notice it evert its long pharynx,
which it uses for burrowing and feeding. The jaws on the surface of the
pharynx can sometimes be seen as dark spots underneath the skin when the
pharynx is not everted. Blood can also be seen through the skin pulsing
through the circulatory system.
This is a crawling polychaete with well-developed parapodia, which
are the small paddle-like appendages associated with each body segment.
Hesionids are carnivores, feeding on a variety of small invertebrates.
This common worm is found throughout False Bay. It resembles an earthworm
as it has few obvious appendages and is similar in shape. Generally a pinkish
color, when observed under bright light the lumbrinerid shows a shining
irridescence as it moves. Lumbrinereids have eversible jaws which they
use for tearing pieces of algae.
Maldanidae (Bamboo Worms)
With segments that are longer than they are wide and distinctive red
bandings, the bamboo worm is easily identifiable. The sand and mucous tubes
can be seen in many areas, rising 1-2 cm above the sand. The tubes are
narrower and more brittle than those of the chaetopterids. The rear
end has an odd frilly appearance.
Nephtyids are well-adapted to both burrowing and crawling on the surface.
They are called shimmy worms, as they make rapid undulations of the body.
Nephtyidae are omnivorous worms, consuming both other animals and plant
An active worm, the nereid can often be seen crawling on the surface
of the sand, although they burrow as well. Individuals as long as 30 cm
are commonly observed. Large epitokes (the reproductive form of the worm)
can be found swarming in the plankton
during reproductive season.
Onuphids form sand and mucous tubes, but unlike most tube-dwelling
polychaetes, they often leave their tubes to forage. They are omnivorous
and may also reach from their tube to capture passing prey.
This is a burrowing polychaete, common in muddy areas. It is a non-selective
This is a carnivorous worm that uses its long pharynx to catch prey.
The parapodia of this worm are flattened and paddle-like.
Terebellidae (Spaghetti Worm)
The terebellids are surface deposit feeders, using their long tentacles
to reach for food particles on the sediment. The extensive tentacles on
the anterior end give this worm its name, and when the tentacles are seen
snaking out over the surface of mud, they are unmistakable. Their tubes
are made of mud and mucous, but are generally not as obvious as tubes from
other worms such as Arenicolidae or Chaetopteridae. The body is usually
green to brown.
Cnidaria (sea anemones)
This sea anemone may be found in muddy areas, usually
attached to a buried rock, cobble, or other hard substrate.
This is a greenish brown anemone commonly found
on eelgrass blades and also seen in the Ulva Area, attached to pieces of
ulva. This is a unique anemone in the way that it broods its young.
Nemertea (ribbon worms)
This long worm, purplish-brown in color with a
light underside, is the most common nemertine in False Bay. It can often
be seen at the sand surface on cool days. It
obtains much of its food by preying on polychaetes. It kills the polychaetes
by everting its proboscis and injecting the prey with a toxin. It is also
known to feed on Ulva (Kozloff,
This is another predatory nemertine worm.
This nemertine is recognizable by its bright orange
coloring. It may reach up to 1 m in length, and can be found with the Ulva
at False Bay. It also preys upon polychaetes and other small invertebrates.
None of these ribbon worms is dangerous to humans.
This small beach hopper occurs on sandy beaches throughout Puget Sound.
It is a typical amphipod in having a body that is taller than it is wide.
This common brachyuran crab is found in false bay primarily in the
rocky area closest to shore. It is found under rocks in sandy or muddy
areas and prefers quiet water. It is an omnivore, eating such things as
algae, small invertebrates, scavenging, and even filter-feeding.
This small crab (<2 cm) is much wider than it is long, and is found
generally in the tubes of Chaetopterus and terebellid worms (Jensen,
1995). In False Bay, we observed this crab living
in terebellid worm tubes. The unusual body form is probably an
adaptation for living as a commensal organism inside of long tubes.
Many hermit crabs occur in False Bay. They inhabit gastropod shells
of varying sizes. This is notable in False Bay because gastropods in general,
and loose shells in particular, are not especially common.
Known as the ghost shrimp, this crustacean lives exclusively in muddy
habitats, and feeds off of organic matter in the mud. It lives in burrows,
and is noticeably helpless when
brought to the surface. It is estimated, however, that larger individuals
(up to 10 cm in body length) may be as much as ten years old (Kozloff,
Commonly called the mud shrimp, this crustacean also lives in burrows
in muddy environments. Like the ghost shrimp, it moves remarkably slowly
when brought to the surface. It is at times found with a commensal
clam, Orobitella rugifera, living attached to the underside
of its abdomen.
This burrowing sea cucumber lives in sand and feeds
by digesting organic material from sand grains that it ingests. This
cucumber is unusual in lacking tube feet, except for the tentacles associated
with the mouth. It is often mistaken for an annelid worm, and lives in
the top 10 cm of sand. Where it occurs in False Bay, in some years it is
This sand dollar usually occurs in sandy environments,
and feeds on organic matter in the sediment. In False Bay it was nearly
always found buried a few centimeters into the sediment, often with a distinctive
circular depression above an individual. The animal is a distinct dark
purplish brown. Commonly found is just the inner shell, or test,
of a dead individual--the test is white.
Commonly known as the bent-nosed clam, this bivalve usually lives
in muddy environments, and is distinguished by the bend in both valves
on the posterior end. It lives buried 10 - 15 cm in the sediment, and is
a filter feeder.
This species of bivalve is extremely similar to the bent-nosed clam,
except that its valves lack the distinctive bend in the posterior region.
It is also found in muddy habitats, and is a filter feeder.
The heart cockle, as it is commonly known, lives on sandy beaches,
just below the surface of the sediment and is a filter feeder. If you are
lucky enough to expose a heart cockle to the sea star Pycnopodia, the cockle
will thrust out its large foot and move it violently in an effort to escape.
This clam lives commensally
on the underside of the mud shrimp, Upogebia. It attaches itself
using a byssus thread (commonly seen attaching mussels to hard surfaces)
to the underside of the shrimp, and lives in the burrow with the shrimp,
filtering food out of the water that flows through the burrow.
Tresus capax (Gaper Clam)
The gaper clam was the largest clam encountered in False Bay, over
10 cm in its largest shell dimension. It was remarkable for its burrowing
speed and power using a large, muscular foot. It earns its name from the
gape left for the siphon, even when the valves are pulled tightly together.
This tiny bivalve does not exceed 5 mm in length, and lives on the
surface of the sand. It is rather common in False Bay (if you look carefully),
and is notable because the females
actually brood their even tinier offspring (Kozloff,
This small snail (<1 cm) is found in eelgrass and ulva beds. Commonly
known as the chink shell, it leaves distinctive doughnut-shaped, slightly
yellow egg masses on the leaves of algae and plants.
Haminoea (Bubble Snail)
Found mainly in the pools of standing water, these are small gastropods,
approximately 2 cm long. Only a small portion of its internal shell can
be seen in the middle of its body. The body is grey to light brown in color.
The bright yellow egg masses,
commonly found in the spring and early summer, are typically deposited
as ribbons attached to some hard surface (bit of shell, eelgrass, log).