1. ACTIVITY #6
MOLLUSCA
Name: ________________________________________________________ Score: _____________
Course/Yr & Sec.: __________ Group #: __________ Date: __________ Prof.: _________________
I. Table 1. Fresh Specimen Examined
Name of the Specimen / Class Distinctive Feature / Characteristics
Green Mussel Class: Bivalvia
Squid Class: Cephalopoda
Snail Class: Gastropoda
Brown Clam/Mussel Class: Bivalvia
Octopus Class: Cephalopoda
It is a large mussel 80-165mm in length. Young ones
have a distinctive bright green shell, which fades to
brown with green edges in adults. The exterior
surface of the shell is smooth with concentric growth
rings and a slightly concave ventral margin. The
inner surface of the shell is smooth with a pale blue
to green hue. The ridge, which supports the ligament
connecting the two shell valves, is finely pitted.
Asian clams (brown clams/mussels) are oval to
nearly triangular in shape, reaching 50 mm in length.
The exterior of the shell is normally a yellow-green to
brown in color with thick, concentric rings. Internally
they may be white or purple and have long, leaf-like
lateral teeth on each side of the beak (native
freshwater mussels have only lateral teeth on one
side of the beak or lack them entirely).
The main body mass is enclosed in the mantle,
which has a swimming fin along each side. These
fins are not the main source of locomotion. The skin
is covered in chromatophores, which enable the
squid to change color to suit its surroundings,
making it practically invisible. The underside is also
almost always lighter than the topside, to
provide camouflage from both prey and predator.
The octopus has an ink sack, opening near the anus,
from which it can discharge a dense, sepia-colored
fluid, creating a smoke screen, and it can also
change its color patterns to become concealed in its
surroundings. The common octopus would be
unique for its appearance alone, with its massive
bulbous head, large eyes, and eight distinctive arms.
Snails are gastropods, and have coiled shells and
retractable tentacles on their heads that are
sometimes tipped with eyes. Their rasp-liked tongue,
the radula, saws away at food. Their most distinctive
feature, though, is torsion. They are twisted in such a
way that the back half of their body sits above their
heads, facing forward. Only one group of gastropods
does not show torsion.

2. II. Draw the Fresh Specimen and label their parts and give their Taxonomic Account.
Taxonomic Account
Phylum: Mollusca
Class: Bivalvia
Order: Mytiloida
Family: Mytilidae
Genus: Perna
Species: P. viridis
Scientific Name:
Perna viridis
Common Name:
Asian green mussel
Taxonomic Account
Phylum: Mollusca
Class: Cephalopoda
Order: Teuthida
Family: Loliginidae
Genus: Lolliguncula
Species: L. brevis
Scientific Name:
Lolliguncula brevis
Common Name:
Atlantic brief squid
Taxonomic Account
Phylum: Mollusca
Class: Gastropoda
Order: Neotaenioglossa
Family: Bithyniidae
Genus: Bithynia
Species: B. tentaculata
Scientific Name:
Bithynia tentaculata
Common Name:
Faucet snail

3. Taxonomic Account
Phylum: Mollusca
Class: Bivalvia
Order: Veneroida
Family: Corbiculidae
Genus: Corbicula
Species: C. fluminea
Scientific Name:
Corbicula fluminea
Common Name:
Asian clam
Taxonomic Account
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Family: Octopodidae
Genus: Octopus
Species: O. vulgaris
Scientific Name:
Octopus vulgaris
Common Name:
Common octopus

4. III. Preserved Specimen
It is a species of bivalve mollusk in the family Carditidae. It
can be found along the Atlantic coast of North America,
ranging from North Carolina to Florida.
Tapestry turban is a species of sea snail, marine
gastropod mollusk in the family Turbinidae. The length of
the shell varies between 30 mm and 100 mm.
Clibanarius vittatus lives inside the empty shell of
a gastropod mollusc. It is found the Caribbean Sea, the
Gulf of Mexico and the western Atlantic Ocean.
Phalium bandatum, or the bonnet shell, is a species of
sea snail, from the family Cassidae. The size of an adult
shell varies between 40 mm and 140 mm.
A large, well-known family of usually white, hard-shelled
clams in which the cardinal teeth are small and the
anterior muscle scar is narrow and long.
It is called "money cowry" because the shells were used in
many Pacific and Indian Ocean countries as a form of
exchange before coinage was in common usage.

5. Like other clams, it is a filter feeder. This species has a
large, heavy shell that ranges from being a pale brownish
color to shades of gray and white.
The adult bears a hard, thin calcareous shell 25-40 mm in
diameter and 25-35 mm high, with four or five whorls. The
shell is somewhat variable in color.
This species lives in shallow water, crawling and burrowing
into the sand. The shell is thin, globose and fragile. The
last whorl covers the rest of the whorls.
Bubble conches lay eggs in long strands: the eggs are
contained in twisted gelatinous tubes. Strombus bulla
moves with a leaping motion.
White Shelled Hermit crab (Dardanus lagopodes), which
usually inhabits shells with wide openings, lived
underwater in the Red Sea.
Anadara lienosa is a species of saltwater bivalves,
commonly called as ark clams, in the family Arcidae.

6. Dardanus pedunculatus usually attain a maximum size of
10 cm (4 in). The carapace is mottled in tan and cream,
while the eyestalks are white with red bands.
This species is a robust brown snail, 2 cm high, with dark
brown markings and a pointed spire. The shell is thin, with
6 to 7 whorls and a sharp apex.
The adult bears a hard, thin calcareous shell 25-40 mm in
diameter and 25-35 mm high, with four or five whorls. The
shell is somewhat variable in color.
Shells of the Pecten sp consist of two valves which are
circular to broadly ovate with the right valve usually more
inflated than the left valve.
Conch shell is a tropical marine gastropod mollusk, in the
genus Strombus, having large, often brightly colored spiral
shells and edible flesh.
The shell background color is a creamy white. Different
individuals may have shells with varying degrees of pale to
dark brown markings.

7. Conus geographus has a broad, thin shell, cylindrically
inflated. It grows to about 4-6 inches in length. The size of
an adult shell varies between 43 mm and 166 mm.
Thorny oyster is more closely related to the scallop. They
have a well developed middle mantle that carries sensory
tentacles with multiple eyes around the shell edges.
The size of the shell is generally between 35 mm and 60
mm (maximum 90 mm). It is a purple-gray mottled with
brown-black dotted spots.
Ostrea edulis is a species of oyster native to Europe and
commonly known as the European flat oyster. Adults
range from 3.8-11 cm (1.5 to 4.3 in) across.
Cypraeidae have adult shells which are very rounded,
almost like an egg; they do not look like a typical gastropod
shell because the shells are extremely smooth and shiny.
Teeth coarse, extending only slightly out of the aperture.
Base rounded, white or partly fawn. The whole surface
marked with white spots of varying size.

8. These attractive univalve mollusks are highly valued by
shell collectors. They usually grow to around 10 cm in
length and have very distinguished colors and patterns.
The shell of Acanthocardia tuberculata can reach a size of
about 95 mm. This shell is robust, equivalve, inflated and
slightly inequilateral, with crenulated margins.
The shell of Venerupis philippinarum is elongate, oval, and
sculptured with radiating ribs. It grows to 7.5 cm (3.0 in)
across and 3.5 cm (1.4 in) in width.
Cardita laticostate is a bivalve mollusc of the family
Carditidae. It is found from low tide to depths of
approximately 185 m.
Cerastoderma edule, commonly known as the common
cockle, is a species of edible saltwater clam. This species
is found in coastal areas of the eastern Atlantic Ocean.
Lucina sp in the family Lucinidae is a family of saltwater
clams, marine bivalve mollusks. They have rounded shells
with forward-facing projections.

9. Species that make up the family Cancellariidae are quite
diverse. Most are under an inch (25mm) in size, though
some Panamic species are known to reach 4 or 5 in.
It is called "money cowry" because the shells were used in
many Pacific and Indian Ocean countries as a form of
exchange before coinage was in common usage.
Adult snails have a height of around 7 cm and their length
can reach 20 cm or more. The shell has a conical shape,
being about twice as high as it is broad.
They reach on average 38-50 mm of length, and a
maximum size of 90 mm. The shells of these cowries may
various in pattern and size.
Little bear conch has a varied coloration of white, cream or
brown with contrasting spotted color. It is basically 3-5cm
length with thicker shell.
Murex belongs to the family Muricidae. Their elongate
shells highly sculptured with spines or fronds. The inner
surfaces of their ornate shells are often brightly colored.

10. The distinctive rounded shells of common cockles are
symmetrical and are heart-shaped when viewed from the
end.
The shell of Lioconcha castrensis reaches a maximum
length of about 55 mm. The shape of the shell is trigonal
ovate and this species is equivalve.
Dardanus guttatus, also known as Blue-knee hermit, is
carnivorous. It is an active hunter for snails, clams and
other small invertebrates as well as small fish.
Batillaria zonalis is a species of small sandy shore snail,
a marine gastropod mollusk in the family Batillariidae, the
horn snails.
Thin, acute, coeloconoid (approaching conical shape but
with concave sides) shell is imperforate or rarely
umbilicate, with numerous spiral lines.
Pagurus bernhardus is the common marine hermit
crab of Europe's Atlantic coasts. It is about 3.5 cm long,
and is found in both rocky and sandy areas.

11. IV. QUESTIONS
1. What characteristics distinguish phylum Mollusca?
These are the following characteristics that may distinguish the phylum Mollusca: (1) they are
bilaterally symmetrical; (2) their bodies have more than two cell layers, tissues and organs; (3) absent
of different cavities; (4) body possesses a through gut with mouth and anus; (5) has body monomeric
and highly variable in form, may possess a dorsal or lateral shells of protein and calcareous spicules;
(6) has a nervous system with a circum-esophageal ring, ganglia and paired nerve chords; (7) has an
open circulatory system with a heart and an aorta; (8) has gaseous exchange organs called ctenidial
gills; (9) has a pair of kidneys; (10) reproduction normally sexual and gonochoristic; (11) they feed a
wide range of material and lastly; (12) different species from phylum Mollusca live in many types of
environments (terrestrial or marine habitats).
2. Give the ecological importance of mollusks.
Mollusks play an important role in several food chains in ecosystems. Mollusks, which include
land snails, freshwater snails, mussels, clams, and slugs, are vital to healthy ecosystems. They provide
not only food for small animals like birds and fish, but they also supply recycling forest nutrients from
plants and animal wastes, essentially keeping water clean and healthy. Other marine mollusks like
octopus and squid are part of a common human diet, very appreciated in the East, and even oysters
and mussels, consumed all around the world. They are considered as excellent ecological indicators for
they provide a window into the health of the entire ecosystems. Besides, mollusks that are part of the
food industry, pearls for example, made by oysters have high commercial value.
References:
http://en.wikipedia.org/wiki/Perna_viridis
http://en.wikipedia.org/wiki/Lolliguncula_brevis
http://en.wikipedia.org/wiki/Bithynia_tentaculata
http://en.wikipedia.org/wiki/Corbicula_fluminea
http://en.wikipedia.org/wiki/Common_octopus
http://www.earthlife.net/inverts/mollusca.html
http://www.habitat.noaa.gov/pdf/best_management_practices/Preventing%20Spread%20of%20Invasive%20Bivalve%20Species.pdf
http://animals.nationalgeographic.com/animals/invertebrates/common-octopus/
http://www.life123.com/home-garden/gardening-tips/garden-pests/snail-facts.shtml
http://www.biology-questions-and-answers.com/mollusca.html