Upper Eulittoral Zone
High Tide Zone: Also called the Upper
Mid-littoral Zone (Upper Eulittoral) and the high intertidal
zone. This area is flooded only during high tide. Organisms
in this area include anemones, barnacles, brittle stars,
chitons, crabs, green algae, isopods, limpets, mussels,
sea stars, snails, whelks and some marine vegetation. |
This is where the confusion lies bewteen
the barnacles belt & this zone the upper Uelittoral
zone where actually a lot of barnacles like to live.
Pictured here are the small white dots of Semibalanus
balanoides shown above the algae.
The midlittoral zone
is covered and uncovered twice a day by the tides.
Animals in this zone have adapted to being immersed
in air and sea water. |
|
Anemones close when the tide is out, keeping
in the moisture necessary for survival. Mussels close
their shells tightly "clam up" for the same purpose,
and open to feed as the tide brings in their food.
This zones upper level - mean high low water - is
approximately +2.5 feet. The lower level - mean low
low water is approximately 0 feet. It is frequented
by a host of organisms and animals. |
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Species Found in
Upper Eulittoral Exposed Sandy Shore |
Exposed Sandy Shore tend to be dominated by crustaceans.
A sandy beach is made up of minute
grains of sand or crushed shells and rock. Because
it is grainy, wind and water reshape a beach every
day. Sandy shores are exciting places with life in
and underneath the sand and water.
The intertidal zone is the area exposed between high
and low tides. In the intertidal zone, part of the day
is spent in open air and the rest of the day is spent
covered in ocean water. High tide brings
with it nutrients and food. When it goes out, the tide
takes with it waste products and disperses eggs and larvae.
Because of the shifting sands, organisms living in the
intertidal zone on a beach have adapted to these changing
conditions. Without the cover of water, many animals
simply shut down during low tide. Some of the animals
spend most of their life buried under the sand. Others
burrow into the sand when the tide is low or when the
crashing waves hit the shore. Some of the animals feed
on materials that washes ashore. Others filter food from
the water. Still others feed on tiny algae and bacteria
among the sand grains. |


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Eurydice pulchra:
Speckled sea louse (Isopod)
Phylum: Crustacea
Class: Malacostraca
Order: Amphipodidae
Family: Talitridae
Widespread on open coast and estuarine sandy beaches,
with reduced abundance in south-east England
Found in the intertidal zone, on fine to medium grained
sandy shores. Eurydice pulchra occupies a
middle shore zone, but its distribution shifts up shore
on spring tides and down shore on neap tides.
A small and distinctive 'louse-like' isopod. The
body is flattened with an oval outline. It has large
eyes, positioned laterally and a long second pair of
antennae. It may be pale grey to brown in colour, with
black spots covering all surfaces of the body. |
|
Bathyporeia sp: Sand Digger Shrimp (Amphipod)
Found on sandy coasts
of Britain and Ireland. Found in wet, clean,
fine to medium sand, from slightly above the mean tide
level into the shallow sublittoral; often abundant
above mean tide level
Description: A small
crustacean that grows to approximately 6-8 mm in
length. Its body is laterally compressed with two
pairs of antennae and seven pairs of thoracic limbs.
Antenna 1 is shorter than antenna 2, and holds
an accessory flagellum. The basal segment of antenna
1 is very large, and rectangular in shape. The
remaining segments of antenna 1 are smaller and
arise at right angles to the basal segment, a feature
known as geniculate, and characteristic of the
genus. The body appears semi-transparent to white,
with varying degrees of red pigment associated
with the abdomen. The eyes are red in colour and
easily visible. |


Phylum: Crustacea (Arthropods)
Class: Malacostraca
Order: Amphipoda
Family: Haustoriidae (Plump amphipod)
|
Scolelepis squamata: Bristleworm. (Nerine cirratulis)
(Polychaete)
Scolelepis squamata is found in the mid
to lower shore of exposed beaches. Found mainly in
sand or sometimes muddy-sand in vertical burrows lined
with mucus.
Well-draining beaches of coarse to medium grained
mobile sand, generally on exposed coasts, support populations
of burrowing amphipods and the isopod Eurydice
pulchra . The degree of drainage appears to
be a critical factor in determining the presence of
polychaetes; only Scolelepis
squamata appears to be capable of tolerating
the well-drained sediments of this biotope.
Description:
Scolelepis squamata is a slender medium length
worm 5-8 cm long and 2-3 mm wide. There are up to 200
segments and from the 2nd segment there are dorsal
gills and chaetae almost to the tail end. The worm
is a bluish green colour with distinct red vessels
in gills and palps (paired projections from head).
Head is elongated and conical in front and pointed
behind.
Swims in spirals when disturbed. It is listed as a Red List Species -
categorized as Critically
Endangered, Endangered, or Vulnerable. |

Phylum: Annelida (Segmented)
Class: Polychaeta (bristleworms)
Order: Spionida
Family: Spionidae |
Species Found on Sheltered Muddy, Sandy
Shore |
Cerastoderma edule: Common Cockle (Bi-valve)
Widely distributed in estuaries and sandy bays around
the coasts of Britain and Ireland.
Inhabits the surface of sediments, burrowing to a depth of no more than
5 cm. Found on clean sand, muddy sand, mud or muddy gravel from the middle
to lower intertidal, sometimes subtidally.
Description:
The familiar edible cockle. The shell is solid, thick, equivalve, globular
and broadly oval in outline; up to 5 cm long but usually less. Shell with
22-28 radiating ribs, crossed by conspicuous concentric ridges and may
bear short, flat spines. Outer surface off-white, yellowish or brownish.
Growth lines are prominent. |

Phylum: Mollusca
Class: Pelecypoda (Bi-valve molluscs
- lamellibranchs)
Order: Veneroida
Family: Cardiidae (Cockles)
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Macoma balthica : Baltic Tellin
Common in estuarine environments around the British
Isles, with the exception of the south coast.
Macoma balthica lives a few centimetres below
the surface of sand, mud and muddy sand. It is found
from the upper regions of the intertidal into the sublittoral,
particularly in estuaries and on tidal flats. Can tolerate
very low salinities. Macoma balthica is widely distributed throughout
north-west Europe and Britain. It has a plump almost
circular shell, up to 25 mm in length, with umbones close
to the midline. The posterior of the shell may be very
slightly tapered. The colour of Macoma balthica varies
between pink, purple, yellow, white and may be blackened
in sulphide-rich sediments. The colour is either uniform
throughout the shell or in concentric bands.
This picture of brightly coloured shells was a collection
of shells found onRampside beach, Morecambe Bay, Cumbria,
UK.
Macomas are mud-dwelling clams which differ from most
other bivalves in their mode of feeding. Most clams are
filter-feeders. They draw water into a siphon, filter
out nutrients and exhale the filtered water through another
siphon. Macomas are deposit feeders. The inhalent siphon
is very long and and sweeps over the mud, acting like
a vacuum cleaner. |


Phylum: Mollusca
Class: Pelecypoda (Bi-valve molluscs
- lamellibranchs)
Order: Veneroida
Family: Tellinidae |
Scrobicularia
plana: Peppery furrow shell
A bivalve (mollusc) which can be identified
when buried by the star-shaped markings made on the
surface
The peppery furrow shell is found in
estuarine and intertidal conditions and is able to
tolerate low salinities in thick mud or muddy sand.
It burrows up to 20 cm deep in sediments and can be
identified when buried by the characteristic star-shaped
markings made at the surface by its inhalant siphon.
This bivalve has a thin, rounded and
flattened shell and grows up to 6.5 cm in length. Internal
features for identification are the hinge of the valves
(the right valve has two teeth and the left valve one
tooth) and the broad and almost circular pallial sinus.
Externally, the shell is sculptured with fine concentric
lines, the outer surface white, pale grey or yellow
and the inner surface is white. |


Phylum: Mollusca
Class: Pelecypoda (Bi-valve molluscs
- lamellibranchs)
Order: Veneroida
Family: Scrobiculariidae
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Species Found on Rocky Shore |
Barnacles :
Although barnacles may look like mollusks with their
shell-like covering, they are actually crustaceans,
related to lobsters,
crabs and shrimp. The barnacle secretes the calcium-hard plates which
totally encase them. In larvae stage they swim and look like tiny shrimp.
Upon maturing they swim the waters until they find the right place to
stop. They then attached them self to this selected area head first.
The barnacle uses a brown glue like substance to
attach itself firmly. The barnacle attached itself
so strongly to a surface that the its cone base is
still around long after the animal has died. Dentists
have studied this glue like substance to learn more
about its adhesive values. |
Semibalanus balanoides :
Acorn barnacle
Semibalanus
balanoides is a dominant member of the eulittoral
fauna of British rocky shores. It can be found on
shores of all exposure.
It may extend into the lower reaches of estuaries
as it can tolerate salinities down to 20 psu.
Semibalanus balanoides is the
most widespread intertidal barnacle in the British
Isles. It may grow up to 15 mm in diameter and has
6 calcified grey-white shell plates. It may be distinguished
from other barnacles by the presence of a diamond shaped
opercular aperture and a membranous shell base. The
barnacle feeds on zooplankton when immersed, by extending
the thoracic appendages (cirri). It is a cross fertilizing
hermaphrodite and may live for up to 8 years, depending
on its position on the shore.
In fact S balanoides is one of
the most widespread barnacles on the northern hemisphere.
Along the Norwegian
coast it can be found as far north as the western
parts of Finnmark. It is most common in the intertidal
zone (occasionally below) on exposed locations. |


Phylum: Crustacea
Class: Cirripedia
Order: Thoracica
Family: Balanidae
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| Eliminus modestus: |
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