Scientia Agriculturae
www.pscipub.com/SA
E-ISSN: 2310-953X / P-ISSN: 2311-0228
Sci. Agri.
3 (3), 2013: 70-81
© PSCI Publications
Potentials and uses of Fish products and other aquatic animals
J.F.N. Abowei 1 and E. N. Ezekiel2
1. Department of Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria.
2. Department of Science laboratory Technology, School of Applied Science, Rivers State Polytechnic, Bori, Rivers State,
Nigeria.
Corresponding author email: cebealse@yahoo.com
Key words
Fish products
other aquatic animal products
Sea shells
Utilization
ABSTRACT
Fish and other aquatic animal products do not only provide essential
nutrients for the body but of several uses. Fish and other aquatic organisms
are also processed into various food and non-food products. The flesh of
many fish is primarily valued as a source of food; there are many edible
species of fish, and many fish produce edible roe. Familiar marine
molluscs enjoyed as a food source by humans include many species of
clams, mussels, oysters, winkles, and scallops. Some crustaceans
commonly eaten are shrimp, prawn, lobster, crayfish, and crabs.
Echinoderms are not as frequently harvested for food as molluscs and
crustaceans; however sea urchin roe is quite popular in many parts of the
world. Most shellfish eat a diet composed primarily of phytoplankton and
zooplankton. Shellfish are among the most common food allergens. It is
now possible to wear shoes made of salmon leather, a jacket made of perch
leather, or a handbag made of wolffish or cod leather. Sharkskin and
rayskin which are covered with, in effect, tiny teeth can be used for
sandpaper. These skins are also used to make leather and manufacture hilts
of traditional swords. Apart from the medicinal values and their usefulness
in the construction industry of fish products and other animals, their uses
as poultry feed, craft, arts, architectural decorations, traditional use as tools
and fish hooks, personal atonements, cultural and religion significance,
horticulture, musical instruments cannot be overemphasized. This paper
revels potentials and uses of fish products and other aquatic animals to
stimulate research and utilization of fisheries resources in the near future.
in Nigeria and other interested countries.
© 2013 PSCI Publisher All rights reserved.
Introduction
Fish and other aquatic animal products do not only provide essential nutrients for the body but of several uses
(Effiong et al., 2012). Fish and fish products are consumed as food all over the world. With other seafoods, it provides the
world's prime source of high-quality protein: 14–16 percent of the animal protein consumed worldwide (Moghadasian, 2000).
Over one billion people rely on fish as their primary source of animal protein (Tawari and Abowei; 2011). Fish and other
aquatic organisms are also processed into various food and non-food products (Ogamba and Abowei., 2012). In Ancient
Roman society, garum, a type of fish sauce condiment, was popular. Sharkskin and rayskin which are covered with, in effect,
tiny teeth (dermal denticles) were used for the purposes that sandpaper currently is. These skins are also used to make leather.
Rayskin leather (same'gawa) is used in the manufacture of hilts of traditional Japanese swords. Some other species of fish are
also used to make fish leather, and this material is more and more popular among luxury brands such as Prada, Dior, Fendi,
and also emerging designers. Thus, it is now possible to wear shoes made of salmon leather, a jacket made of perch leather, or
a handbag made of wolffish or cod leather. Once tanned, the leather is non smelly and is more strong than other traditional
leathers, for a same thickness. The flesh of many fish is primarily valued as a source of food; there are many edible species of
fish, and many fish produce edible roe.
Other marine life taken as food includes shellfish, crustaceans, and sea cucumber. Sea plants such as kombu are used
in some regional cuisine. A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer created by an
animal that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches
by beachcombers. The shells are empty because the animal has died and the soft parts have been eaten by another animal or
Sci. Agri. 3 (3), 2013: 70-81
have rotted out. In New Zealand, green-lipped mussels and Pacific oysters are commercially farmed with aquaculture methods.
Pāua, scallops, queen scallops and dredge oysters are commercially harvested from the wild (Abbott, 1986).
Shellfish is a culinary and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various
species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater
environments, some kinds are found only in freshwater. In addition a few species of land crabs are eaten, for example
Cardisoma guanhumi in the Caribbean. The term shellfish is used both broadly and specifically. In common parlance, as in
having "shellfish" for dinner, it can refer to anything from clams and oysters to lobster and shrimp. For regulatory purposes it
is often narrowly defined as filter-feeding molluscs such as clams, mussels, and oyster to the exclusion of crustaceans and all
else (Abbott, 1985).
Although the term is primarily applied to marine species, edible freshwater invertebrates such as crayfish and river
mussels are also sometimes grouped under the umbrella of "shellfish". Although their shells may differ, all shellfish are
invertebrates. As non-mammalian animals that spend their entire lives in water they are "fish" in the logical sense; however the
denotion finfish (or finnicle fish) has been developed to distinguish fish as animals defined by having vertebrae from shellfish
in modern terminology.
The word "shellfish" is both singular and plural; the rarely used "shellfishes" is sometimes employed to distinguish
among various types of shellfish. Archaeological finds has shown that humans have been making use of shellfish as a food
item for hundreds of thousands of years. In the present, shellfish dishes are a feature of almost all the cuisines of the world,
providing an important source of protein in many cuisines around the world, especially in the countries with coastal areas
(Abbott and Pete., 1982).
a
b
f
c
g
d
e
h
Figure1. Some popular dishes using shellfish
a.
Raw oysters, opened, and presented on a plate
Source: http//en.wikipedia.org/wiki/file:oyster_p1040741.jpg
b.
A shrimp cocktail
Source: http//en.wikipedia.org/wiki/file:cocktail_1_pg_060702_.jpg
c.
Cooked mussels
Source: http//en.wikipedia.org/wiki/file:Rheinische_Muschein.jpg
d.
Sakura ebi
Source: http//en.wikipedia.org/wiki/file:sakura_ebi.jpg
e.
Boiled Maine Lobster
Source: http//en.wikipedia.org/wiki/file:Boiled marine_lobster.jpg
f.
Scallop sandwich
Source: http//en.wikipedia.org/wiki/file:zoo_09_bg120306.jpg
g.
Large shrimp or prawns
Source: http//en.wikipedia.org/wiki/file:Gambas_in_xxmiglia_market.jpg
h.
A dish of cooked freshwater nerites
Source: http//en.wikipedia.org/wiki/file:cooked_snail_found_In_Rajan_River.jpg
Despite the name, shellfish are not a kind of fish, but are simply animals that live in water (Jamabo and Abowei;
2010). Many varieties of shellfish (crustaceans in particular) are actually closely related to insects and arachnids, making up
one of the main classes of the phylum Arthropoda (Deekae and Abowei., 2010; Abowei and George 2010). Cephalopods
(squid, octopus, and cuttlefish) and bivalves (clams, oysters) are molluscs, as are snails and slugs (Abbott and Pete., 1982).
Familiar marine molluscs enjoyed as a food source by humans include many species of clams, mussels, oysters, winkles, and
scallops. Some crustaceans commonly eaten are shrimp, prawn, lobster, crayfish, and crabs. Echinoderms are not as frequently
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Sci. Agri. 3 (3), 2013: 70-81
harvested for food as molluscs and crustaceans, however sea urchin roe is quite popular in many parts of the world. Most
shellfish eat a diet composed primarily of phytoplankton and zooplankton. Shellfish are among the most common food
allergens (Abbott, 1985)..
In the Japanese cuisine, chefs often use shellfish and their roe in different dishes (Plate 1). Sushi (vinegared rice,
topped with other ingredients, including shellfish, fish, meat and vegetables), feature both raw and cooked shellfish. Sashimi
primarily consists of very fresh raw seafood, sliced into thin pieces (Abbott and Pete., 1982). Both sushi and sashimi are served
with soy sauce and wasabi paste (a Japanese horseradish root, a spice with extremely strong hot flavor), thinly-sliced pickled
ginger root, and a simple garnish such as shiso (a kitchen herb, member of the mint family) or finely shredded daikon radish,
or both. Shellfish is a common part of indigenous cuisines throughout the globe. In the Japanese cuisine, chefs often use
shellfish and their roe in different dishes. Sushi feature both raw and cooked shellfish. Sashimi primarily consists of very fresh
raw seafood, sliced into thin pieces. Both sushi and sashimi are served with soy sauce and wasabi paste (a Japanese horseradish
root, a spice with extremely strong hot flavor), thinly-sliced pickled ginger root, and a simple garnish such as shiso (a kitchen
herb, member of the mint family) or finely shredded daikon radish, or both. (Abbott, 1974).
In the United States, there are numerous popular books and field guides on the subject of shell-collecting (Abbott,
1985).. Although there are a number of books about land and freshwater mollusks, the majority of popular books emphasizes,
or focuses exclusively on, the shells of marine mollusks. Both the science of studying mollusk shells and the hobby of
collecting and classifying them are known as conchology. The line between professionals and amateur enthusiasts is often not
well defined in this subject, because many amateurs have contributed to, and continue to contribute to, conchology and the
larger science of malacology. Many shell collectors belong to "shell clubs" where they can meet others who share their
interests (Abbott and Pete., 1982).
A large number of amateurs collect the shells of marine mollusks, and this is partly because many shells wash up
empty on beaches, or live in the intertidal or sub-tidal zones, and are therefore easily found and preserved without much in the
way of specialized equipment or expensive supplies. Some shell collectors find their own material and keep careful records, or
buy only "specimen shells", which means shells which have full collecting data: information including how, when, where, in
what habitat, and by whom, the shells were collected. On the other hand, some collectors buy the more widely available
commercially-imported exotic shells, the majority of which have very little data or none at all (Abbott , 1985)..
To museum scientists, having full collecting data (when, where, and by whom it was collected) with a specimen is far
more important than having the shell correctly identified. Some owners of shell collections hope to be able to donate their
collection to a major natural history or zoology museum at some point, however, shells with little or no collecting data are
usually of no value to science, and are likely not to be accepted by a major museum (Abbott, 1985). Apart from any damage to
the shell that may have happened before it was collected, shells can also suffer damage when they are stored or displayed. For
an example of one rather serious kind of damage see Byne's disease.
When the word "seashells" is used to refer only to the shells of marine mollusks then studying seashells is part of
conchology (Abbott and Pete., 1982). Conchologists or serious collectors who have a scientific bias are in general careful not
to disturb living populations and habitats: even though they may collect a few live animals, most responsible collectors do not
often over-collect or otherwise disturb ecosystems. When studying the whole molluscan animal is included as well as studying
the shell, then the study is known as malacology; a person who studies mollusks is known as a malacologist. Seashells are
commonly found in beach drift, which is natural detritus deposited along strandlines on beaches by the waves and the tides
(Abbott, 1985). Shells are very often washed up onto a beach empty and clean, the animal having already died, and the soft
parts having rotted away or having been eaten by either predators or scavengers. Empty seashells are often picked up by
beachcombers. However, the majority of seashells which are offered for sale commercially have been collected alive (often in
bulk) and then killed and cleaned, specifically for the commercial trade. This type of large-scale exploitation can sometimes
have a strong negative impact on local ecosystems, and sometimes can significantly reduce the distribution of rare species.
The term seashell usually refers to the exoskeleton of an invertebrate (Abbott and Pete., 1982). Most shells that are
found on beaches are the shells of marine mollusks, partly because many of these shells endure better than other seashells.
Apart from mollusk shells, other shells that can be found on beaches are those of barnacles, horseshoe crabs and brachiopods.
Marine annelid worms in the family Serpulidae create shells made of calcareous tubes cemented onto other surfaces. The shells
of sea urchins are called tests, and the moulted shells of crabs and lobsters are called exuviae. While most seashells are
external, some cephalopods have internal shells (Abbott , 1985).
Seashells have been admired, studied and used by humans for many different purposes throughout history and prehistory. But seashells are not the only kind of shells. In a variety of habitats it is possible to find shells from freshwater animals
such as freshwater mussels and freshwater snails, and it is also possible to find shells from land snails. This paper revels
potentials and uses of fish products and other aquatic animals to stimulate research and utilization of fisheries resources in the
near future. In Nigeria and other interested countries (Abbott, 1974).
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Molluscan seashells
The word seashell (Plate 2) is often used to mean only the shell of a marine mollusk. Marine mollusk shells that are
familiar to beachcombers and thus most likely to be called "seashells" are the shells of marine species of bivalves (or clams),
gastropods (or snails), scaphopods (or tusk shells), polyplacophorans (or chitons), and cephalopods (such as nautilus and
spirula) (Abbott, 1974). These shells are very often the most commonly encountered, both in the wild, and for sale as
decorative objects. Marine species of gastropods and bivalves are more numerous than land and freshwater species, and the
shells are often larger and more robust. The shells of marine species also often have more sculpture and more color, although
this is by no means always the case.
In the tropical and sub-tropical areas of the planet, there are far more species of colorful, large, shallow water shelled
marine mollusks than there are in the temperate zones and the regions closer to the poles. Although there are a number of
species of shelled mollusks that are quite large, there are vast numbers of extremely small species too. (Abbott, 1974). Not all
mollusks are marine however, there are numerous land and freshwater mollusks, see for example snail and freshwater bivalves.
And not all mollusks have an external shell: some mollusks such as some cephalopods (squid and octopuses) have an internal
shell, and many mollusks have no shell, see for example slug and nudibranch (Abbott, 1974).
Bivalves
Bivalves are often the most common seashells that wash up on large sandy beaches or in sheltered lagoons. They can
sometimes be extremely numerous. Very often the two valves become separated. Shell Beach, Western Australia is a beach
which is entirely made up of the shells of the cockle Fragum erugatum as shown in Plate 2b.
Gastropods
Certain species of gastropod seashells (the shells of sea snails) can sometimes be common, washed up on sandy
beaches, and also on beaches that are surrounded by rocky marine habitat (plate 2c).
Polyplacophorans
Chiton plates or valves often wash up on beaches in rocky areas where chitons are common (Plate 2d). Chiton shells,
which are composed of eight separate plates and a girdle, usually come apart not long after death, so they are almost always
found as disarticulated plates. Plates from larger species of chitons are sometimes known as "butterfly shells" because of their
shape.
a
b
c
d
Plate 2 Sea Shells
a.
Seashells hand picked from beach drift
Source: http//en.wikipedia.org/wiki/file:Seashells_North_Whales_1985.jpg
b.
Single valves of the bivalve Senilia senilis, plus two gastropods
Source: http//en.wikipedia.org/wiki/file:coquillagesFadiouth.jpg
c.
Numerous Turritella gastropod shells washed up on a beach
Source: http//en.wikipedia.org/wiki/file:Sea_shells,_playa_grande,_costa_rica.jpg
d.
Loose valves or plates from Chiton tuberculatus from the beachdrift
Source: http//en.wikipedia.org/wiki/file:chitin_tuberculatus_plates.jpg
Cephalopods
Only a few species of cephalopods (Plate 3) have shells (either internal or external) that are sometimes found washed
up on beaches. Some cephalopods such as Sepia (Plate 3a), the cuttlefish, have a large internal shell, the cuttlefish bone, and
this often washes up on beaches in parts of the world where cuttlefish are common. Spirula spirula is a deep water squid-like
cephalopod. It has an internal shell which is small (about 1 in or 24 mm) but very light and buoyant. This chambered shell
floats very well and therefore washes up easily and is familiar to beachcombers in the tropics (Abbott, 1974).
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Nautilus is the only genus of cephalopod that has a well-developed external shell. Females of the cephalopod genus
Argonauta create a papery egg case which sometimes washes up on tropical beaches and is referred to as a "paper nautilus"
(plate 3b). The largest groups of shelled cephalopods, the ammonites, are extinct, but their shells are very common in certain
areas as fossils.
Cuttlebone from a Sepia sp.
Shells of 3 species of Nautilus
a
b
Figure3. Species of cephalopods
Sources:
a .http//en.wikipedia.org/wiki/file:cuttlebone.jpg
b. source: http//en.wikipedia.org/wiki/fileNautilus_species_shell.png
Molluscan seashells used by other animals
Empty molluscan seashells are a sturdy, and usually readily available, "free" resource which is often easily found on
beaches, in the intertidal zone, and in the shallow subtidal zone. As such they are sometimes used second-hand by animals
other than humans for various purposes, including for protection (as in hermit crabs) and for construction.
Mollusks
Carrier shells in the family Xenophoridae are marine shelled gastropods, fairly large sea snails. Most species of
xenophorids cement a series of objects to the rim of their shells as they grow. These objects are sometimes small pebbles or
other hard detritus. Very often shells of bivalves or smaller gastropods are used, depending on what is available on the
particular substrate where the snail itself lives. It is not clear whether these shell attachments serve as camouflage, or whether
they are intended to help prevent the shell sinking into a soft substrate. Small octopuses sometimes use an empty shell as a sort
of cave to hide in, or hold seashells around themselves as a form of protection like a temporary fortress (plate 4a).
Invertebrates
Almost all genera of hermit crabs use or "wear" empty marine gastropod shells throughout their lifespan, in order to
protect their soft abdomens, and in order to have a strong shell to withdraw into if attacked by a predator. Each individual
hermit crab is forced to find another gastropod shell on a regular basis, whenever it grows too large for the one it is currently
using. Some hermit crab species live on land and may be found quite some distance from the sea, including those in the
tropical genus Coenobita (plate 4b).
a
b
Figure4 . Molluscan seashells used by other animals
a.
b.
An ocellated (spotted) octopus using a clamshell as a shelter
Source: http//en.wikipedia.org/wiki/file:Ocellated_octopus.jpg
Marine hermit crab Diogenes pugilator, using a shell of the dog whelk Nassarius reticulatus
Source: http//en.wikipedia.org/wiki/file:Diogenes_pugilator.jpg
Identification
Seashells are usually identified by consulting general or regional shell-collecting field guides, and specific scientific
books on different taxa of shell-bearing mollusks (monographs) or "iconographies" (limited text - mainly photographs or other
illustrations). (For a few titles on this subject in the USA, see the list of books at the foot of this article.) Identifications to the
species level are generally achieved by examining illustrations and written descriptions, rather than by the use of Identification
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keys, as is often the case in identifying plants and other phyla of invertebrates. The construction of functional keys for the
identification of the shells of marine mollusks to the species level can be very difficult, because of the great variability within
many species and families. The identification of certain individual species is often very difficult, even for a specialist in that
particular family. Some species cannot be differentiated on the basis of shell character alone.
Numerous smaller and more obscure mollusk species are yet to be discovered and named. In other words, they have
not yet been differentiated from similar species and assigned scientific (binomial) names in articles in journals recognized by
the International Commission on Zoological Nomenclature (ICZN). Large numbers of new species are published in the
scientific literature each year. There are currently an estimated 100,000 species of mollusks worldwide.
The term seashell is also applied loosely to mollusk shells that are not of marine origin, for example by people
walking the shores of lakes and rivers using the term for the freshwater mollusk shells they encounter (Plate 5a-c ). Seashells
purchased from tourist shops or dealers may include various freshwater and terrestrial shells as well. Non-marine items offered
may include large and colorful tropical land snail shells, freshwater apple snail shells, and pearly freshwater unionid mussel
shells. This can be confusing to collectors, as non-marine shells are often not included in their reference books (Abbott, 1974).
a
a.
b
c
Plate 5 Many Mollusk species and families
The shell of a large tropical land snail (upper right), and a shiny freshwater apple snail shell (center)
Source: http//en.wikipedia.org/wiki/file:Shells01.jpg
b.
Seashells washed up on the beach of Mactra corallina
Source: http//en.wikipedia.org/wiki/fileconchiglie_seashells01.jpg
c.
Hand-picked molluscan seashells (bivalves and gastropods)
source: http//en.wikipedia.org/wiki/file:selection_of_seashells.jpg
Processed fish products
Shellfish were, and continue to be, an important part of the diet of Māori living on the coast. Traditionally, shellfish gathering was the work of women and girls, who harvested a variety of species such as toheroa, tuatua and pipi (all Paphies
species), pāua (Haliotis species), tuangi (Austrovenus stutchburyi), rock oyster (Saccostrea cucullata), dredge oyster (Ostrea
chilensis), mussels (Perna canaliculus, Mytilus edulis) and scallops (Pecten novaezelandiae). These are still commonly eaten
today. Many other coastal shellfish that were once eaten, such as Cook’s turban (ngāruru, Cookia sulcata) and ringed dosinia
(harihari, Dosinia anus), are seldom gathered by Māori or Europeans today.
Shells of oysters and periwinkles are sometimes used for the manufacture of of paints and also mixed with cement
and sand to build houses
Since the 1990s Asian immigrants have begun harvesting less well-known coastal shellfish, such as limpets and cat’s
eyes, for food.
Surimi refers to a Japanese food product intended to mimic the meat of lobster, crab, and other shellfish. It is typically
made from white-fleshed fish (such as pollock or hake) that has been pulverized to a paste and attains a rubbery texture when
cooked.
In commercial fishing, fishes harvested may be exported for exchange earning. Locally it is being used for trade by
barter.
Fisheries may serve for tourism and sporting, Angerlers and sport fishermen go to fisheries establishments for
recreation.
Fish and turtle eggs called CAVIARE prepared and salted are quality food eaten by man.
Fish possesses high calorific fats, high quality proteins, fat soluble vitamins ( A, D, E and K) and some mineral salts
necessary for healthy growth and maintenance.
The skin of some cartilaginous fishes such as dried and specially treated to very specially leader called shagreen and
used for hand bags, wallets, belts and shoes,
The dried skin (shagreen) can be used like glass papers for polishing surfaces.
The scales of some fishes produce collagen substances that when coated on the inside beads make artificial pearls.
Oysters contain pearls which are polished and worn as jewelry.
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Fish glue is made by boiling the skin, bones and swim bladders of fish. Fish glue has long been valued for its use in
all manner of products from illuminated manuscripts to the Mongolian war bow.
Fish oil is recommended for a healthy diet because it contains the omega-3 fatty acids, eicosapentaenoic acid (EPA),
and docosahexaenoic acid (DHA), precursors to eicosanoids that reduce inflammation throughout the body.
Fish oils besides being used as food, are used in the manufacture of soap and drugs (eg. cod liver oil).
Fish emulsion is a fertilizer emulsion that is produced from the fluid remains of fish processed for fish oil and fish
meal industrially.
Fish bones are used the manufacture of glues and fertilizers.
Fish hydrolysate is ground up fish carcasses. After the usable portions are removed for human consumption, the
remaining fish body – guts, bones, cartilage, scales, meat, etc. – are put into water and ground up.
Fish meal is made from both whole fish and the bones and offal from processed fish. It is a brown powder or cake
obtained by rendering pressing the whole fish or fish trimmings to remove the fish oil. It used as a high-protein supplement in
aquaculture feed.
Fish sauce is a condiment that is derived from fish that have been allowed to ferment. It is an essential ingredient in
many curries and sauces.
The lining of the gas bladder of sturgeons is used for making isinglass, a shiny powder used as adsorbents in wine
industry.
Tatami iwashi is a Japanese processed food product made from baby sardines laid out and dried while entwined in a
single layer to form a large mat-like sheet.
Other processed products
Pearls, mother-of-pearl, and abalone are valued for their lustre. Traditional methods of pearl hunting are now virtually
extinct.
Sea horse, star fish, sea urchin and sea cucumber are used in traditional Chinese medicine.
The Sea snails Murex brandaris and Murex trunculus are used to make the pigment Tyrian purple.
Some sepia pigment is made from the inky secretions of cuttlefish.
Kelp is a major source of iodine, can be used as fertilizer, and kelp ash can be used in soap and glass productions.
Byproducts
A shimmery substance found on fish scales, most usually obtained from herring and one of many by-products of
commercial fish processing, can also be used for pearlescent effects, primarily in nail polish, but is now rarely used due to its
high cost, bismuth oxychloride flakes being used as a substitute instead.
Live Fish & Pets
Fish may also be collected live for research, observation, or for the aquarium trade.
Cultural significance
Currency: Seashells have been used as a medium of exchange in various places, including many Indian Ocean and
Pacific Ocean islands, also in North America, Africa and the Caribbean. The most common species of shells to be used as
currency have been Cypraea moneta, the "money cowry", and certain tusk shells or dentalium, such as those used in North
Western North America for many centuries (Plate. 6a).
Some tribes of the indigenous peoples of the Americas used shells for wampum and hair pipes. The Native American
wampum belts were made of the shell of the quahog clam.
It is of historic interest that the Dutch East India Company, a major force in the colonization of the Indian and Pacific
Oceans, amassed a large portion of its vast fortune via trading shell money of the species Cypraea moneta and Cypraea
annulus, in exchange for commodities such as spices, exotic animals, and gemstones, all of which were considered valuable in
Europe at the time.
Traditional uses
Shells were used by Māori in a variety of ways:
Fish hooks: Cook’s turban shells were used to fashion the tips of hooks, and the iridescent inner shell of pāua was used for
fishing lures (Plate 6b).
Tools
Seashells have often been used as tools, because of their strength and the variety of their shapes.
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Giant clams (Family Tridacnidae) have been used as bowls, and when big enough, even as bathtubs and baptismal fonts.
Melo melo, the "bailer volute", is so named because Native Australians used it to bail out their canoes.
Many different species of bivalves have been used as scrapers, blades, clasps, and other such tools, due to their shape.
Some marine gastropods have been used for oil lamps, the oil being poured in the aperture of the shell, and the siphonal canal
serving as a holder for the wick.
Scrapers and cutters. Mussel shells were used for cutting hair and for scraping flax leaves in order to expose the fibres
below the outer green layer. Tuatua shells were used for scaling fish.
Trumpets. Trumpets known as pūtara were made from New Zealand’s largest sea snail, Charonia lampas, by fitting a
wooden mouthpiece to the top of an empty shell. A loud note is produced because the sound is amplified within the shell. The
large, rare triton shell (Charonia tritonis) was also used. Live tritons are not found in New Zealand, although sometimes their
dead shells wash up on northern shores.
Adornment. Tusk shells were used as anklets and necklaces, and pieces of pāua shell were sometimes hung on skirts.
Inlay in carvings. Pieces of pāua shell were used as inlay in wooden and bone carvings, often representing eyes.
Bowls and containers. Dosinia species and scallop shells were used to hold pigments for tattooing. Pāua ashtrays, used by
Māori and Pakeha alike, came into their own after the 1950s.
Horticulture
Because seashells are in some areas a readily available bulk source of calcium carbonate, shells such as oyster shells
are sometimes used as soil conditioners in horticulture.
The shells are broken or ground into small pieces in order to have the desired effect of raising the pH and increasing
the calcium content in the soil.
Crushed shells are used as loose paving in gardens, and for decoration.
Religion and spirituality
Seashells have played a part in religion and spirituality, sometimes even as ritual objects.
In Christianity, the scallop shell is considered to be the symbol of Saint James the Great, see Pecten jacobaeus.
In Hinduism left-handed shells of Turbinella pyrum (the sacred shankha) are considered to be sacred to the god Vishnu. The
person who finds a left-handed chank shell (one that coils to the left) is sacred to Vishnu, as well. The chank shell (Plate 6c)
also plays an important role in Buddhism.
Cowries have often been considered to be symbols of female fertility. They were often treated as actual fertility
charms. The dorsum of the shell resembles a pregnant belly, and the underside of the shell resembles a vulva. In the South
Indian state of Kerala, cowries are used for making astrological predictions.
In Santería, shells are used for divination purposes.
The Moche culture of ancient Peru worshipped animals and the sea, and often depicted shells in their art.
Religious dietary restrictions
The Jewish laws of Kashrut forbid the eating of shellfish. The book of Leviticus prohibits the consumption of
shellfish. In Islam, the Shafi'i, Maliki and Hanbali schools allow it, while the Hanafi school does not allow it in Sunni Islam.
The Shi'ite school (Ja'fari) does not allow it. Seventh-day Adventists eat no shellfish.
a
b
c
Plate 6. Some uses of sea shells
a.
1742 drawing of shells of the money cowry, Cypraea moneta
Source: http//en.wikipedia.org/wiki/file:Cypraea-monesta-001.jpg
b.
Shellfish hook
Source: http//www.teara.govt.nz/en/shellfish/7/3
c.
A sacred chank shell on the flag of Travancore, India
Source: http//en.wikipedia.org/wiki/file:Travancore.jpg
Musical instruments
Seashells have been used as musical instruments (Plate 7a-c), wind instruments for many hundreds if not thousands of
years (Ewers, 1997). Most often the shells of large sea snails are used, as trumpets, by cutting a hole in the spire of the shell or
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Sci. Agri. 3 (3), 2013: 70-81
cutting off the tip of the spire altogether. Various different kinds of large marine gastropod shells can be turned into "blowing
shells", however the most commonly encountered species used as "conch" trumpets are:
The sacred chank, Turbinella pyrum, known in India as the shankha. In Tibet it is known as "dung-dkar".
The Triton shell also known as "Triton's trumpet" Charonia tritonis which is used as a trumpet in Melanesian and
Polynesian culture and also in Korea and Japan. In Japan this kind of trumpet is known as the horagai. In Korea it is known as
the nagak. In some Polynesian islands it is known as "pu".
The Queen Conch Strombus gigas, is or was sometimes used as a trumpet in the Caribbean.
a
b
c
Figure 7 . Musical instruments
a.
Hindu priest sounding a ritual trumpet made from Turbinella pyrum
Source: http//en.wikipedia.org/wiki/file:Hindu_priest_blowing_conch_during-punja.jpg
b.
A Talibian Trumpet
Source: http//www.teara.govt.nz/en/shellfish/7/4
c.
Korean military procession with Charonia trumpets
Source: http//en.wikipedia.org/wiki/file:Gyeonbokgung-March-01.jpg
Personal adornment
For nearly 20 years after the end of the Second World War, pāua earrings, necklaces, rings and souvenirs were
manufactured solely by disabled servicemen. Since this monopoly on the shell has been lifted, there has been a huge increase
in the range of pāua jewellery, often set in silver, from craftspeople using both contemporary and traditional designs (Plate 8ab).
Pāua pearls have been produced since the mid-1990s. They are grown as half-round pearls inside the living pāua. The
two halves are glued together to produce the finished product.
Whole seashells or parts of sea shells have been used as jewelry or in other forms of adornment since prehistoric
times. Mother of pearl was historically primarily a seashell product, although more recently some mother of pearl comes from
freshwater mussels.
Shell necklaces have been found in Stone Age graves as far inland as the Dordogne Valley in France.
Seashells are often used whole and drilled, so that they can be threaded like beads, or cut into pieces of various
shapes. Sometimes shells can be found that are already "drilled" by predatory snails of the family Naticidae. Fine whole shell
necklaces were made by Tasmanian Aboriginal women for more than 2,600 years. The necklaces represent a significant
cultural tradition which is still practised by Palawa women elders. The shells used include pearly green and blue-green
maireener (rainbow kelp) shells, brown and white rice shells, black cats' teeth shells and pink button shells.
Naturally-occurring, beachworn, cone shell "tops" (the broken-off spire of the shell, which often has a hole worn at
the tip) can function as beads without any further modification. In Hawaii these natural beads were traditionally collected from
the beach drift in order to make puka shell jewelry. Since it is hard to obtain large quantities of naturally-occurring beachworn
cone tops, almost all modern puka shell jewelry uses cheaper imitations, cut from thin shells of other species of mollusk, or
even made of plastic.
Shells historically have been and still are made into, or incorporated into, necklaces, pendants, beads, earrings,
buttons, brooches, rings, hair combs, belt buckles and other uses.
The shell of the large "bullmouth helmet" sea snail, scientific name Cypraecassis rufa, was historically, and still is,
used to make valuable cameos.
Mother of pearl from many seashells including species in the family Trochidae, Turbinidae, Haliotidae, and various
pearly bivalves, has often been used in jewelry, buttons, etc.
In London, Pearly Kings and Queens traditionally wear clothing covered in patterns made up of hundreds of "pearl
buttons", in other words, buttons made of mother-of-pearl or nacre. In recent years however, the majority of "pearl buttons" are
imitations that are made of pearlescent plastic.
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Sci. Agri. 3 (3), 2013: 70-81
a
b
Figure8. Seashells used for personal adornment
a.
Use of gastropod shells, specifically cowries, in traditional dress of the Kikuyu people of Kenya, Africa
Source: http//en.wikipedia.org/wiki/file:Kikuyu_woman_traditional_dress.jpg
b.
A Pearly King and Queen in London
Source: http//en.wikipedia.org/wiki/file: Pearlykingandqueen.jpg
Crafts
"Sailor's Valentines" were late 19th century decorative keepsakes which were made in the Caribbean, and which were
often purchased by sailors to give to their loved ones back home for example in England. These valentines consisted of
elaborate arrangements of small seashells glued into attractive symmetrical designs, which were encased on a wooden (usually
octagonal) hinged box-frame. The patterns used often featured heart-shaped designs, or included a sentimental expression of
love spelled out in small shells. The making of shellwork artifacts is a practice of Aboriginal women from La Perouse in
Sydney, New South Wales, dating back to the 19th century. Shellwork objects include baby shoes, jewelry boxes and replicas
of famous landmarks, including the Sydney Harbour Bridge and the Sydney Opera House. The shellwork tradition began as an
Aboriginal women's craft which was adapted and tailored to suit the tourist souvenir market, and which is now considered high
art (Plate 9). These decorative arrangements were a popular way to display seashells at the time
Figure9.Illustration from an 18th-century book, edited by Albertus Seba.
Source: http//en.wikipedia.org/wiki/file: Albertus_seba_Muschein.jpg
Architectural decoration
Small pieces of colored and iridescent shell have been used to create mosaics and inlays, which have been used to
decorate walls, furniture and boxes. Large numbers of whole seashells, arranged to form patterns, have been used to decorate
mirror frames, furniture and man-made grottos.
Art
A very large outdoor sculpture at Akkulam of a gastropod seashell (Plate 10a) is a reference to the sacred chank shell
Turbinella pyrum of India. Maggi Hambling designed a striking 13 ft (4 m) high sculpture of a scallop shell (Plate 10b) which
stands on the beach at Aldeburgh, in England. The goddess of love, Venus or Aphrodite is often traditionally depicted rising
from the sea on a seashell. In the Birth of Venus (Botticelli), Botticelli depicted the goddess Venus rising from the ocean on a
scallop shell (plate 10c).
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Sci. Agri. 3 (3), 2013: 70-81
a
b
c
Figure 10. Various arts from sea shells
a.
Enormous seashell sculpture at Akkulam, Trivandum, India
Source: http//en.wikipedia.org/wiki/file: Akkulam, _shanku.jpg
b.
Large sculpture of a scallop on the beach at Aldeburgh, England
Source: http//en.wikipedia.org/wiki/file: The scallop,_Maggi_Hambling,_Aldeburgh.jpg
c.
Aphrodite, 1st century BC, 13 cms, 5 in
Source: http//en.wikipedia.org/wiki/file: Aphrodite_Anadyomene_Louvre_CA2288.jpg
Poultry feeds
Sea shells found in the creek and backwater of the coast of west India are used as an additive to poultry feed. They are
crushed and mixed with jawar maaze and dry fish.
In the past, they were taken from beach deposits around the country, such as at Quail Island in Canterbury and the
extensive shell ridges in the Firth of Thames. Another source is the by-product of oyster, mussel and scallop harvests.
Shells of other marine invertebrates
Many arthropods have sclerites, or hardened body parts, which form a stiff exoskeleton made up mostly of chitin. In
crustacean (Abbott and Pete., 1982) especially those of the class Malacostraca (crabs, shrimps and lobsters; for instance), the
plates of the exoskeleton may be fused to form a more or less rigid carapace. Moulted carapaces of a variety of marine
malacostraceans often wash up on beaches (Plate 11a). The horseshoe crab (Plate 11b) is an arthropod of the family Limulidae.
The shells or exuviae of these arachnids are common in beach drift in certain areas of the world. Some echinoderms such as
sea urchins (plate 11c), including heart urchins and sand dollars, have a hard "test" or shell. After the animal dies, the flesh rots
out and the spines fall off, and then fairly often the empty test washes up whole onto a beach, where it can be found by a
beachcomber. These tests are fragile and easily broken into pieces.
The brachiopods, or lamp shells (Plate 11d), superficially resemble clams, but the phylum is completely unrelated to
mollusks. Most lines of brachiopods ended during the Permian-Triassic extinction event, and their ecological niche was filled
by bivalves. A few of the remaining species of brachiopods occur in the low intertidal zone and thus can be found live by
beachcombers.
a
b
c
d
Figure 11. Shells of some marine invertebrates
a. The moulted carapace of a lady crab found on the beach at Long Beach, Long Island, New York State
Source: http//en.wikipedia.org/wiki/file: crab_from_long_Island.jpg
b. Shell of horseshoe crab on a beach
Source: http//en.wikipedia.org/wiki/file: Horseshoe_crab_remains_jpg
c. Sea urchin test
Source: http//en.wikipedia.org/wiki/file: Sea_urchin_test_5629_03_22.jpg
d. A whole animal of the brachiopod Lingula anatina from Australia with the shell showing on the left
Source: http//en.wikipedia.org/wiki/file: LingulaanatinaAA.jpg
Annelids
Some polychaetes, marine annelid worms in the family Serpulidae, secrete a hard tube made of calcium carbonate,
adhering to stones or other shells. This tube resembles, and can be confused with, the shell of marine gastropod mollusks in the
family Vermetidae, the worm snails.
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Other more atypical kinds
A few other categories of marine animals leave remains which might be considered "seashells" in the widest possible
sense of the word (Abbott, 1985).
Cheloniansplate (12a): Sea turtles have a carapace and plastron of bone and cartilage which is developed from their
ribs. Infrequently a turtle "shell" will wash up on a beach.
Hard corals(12b): Pieces of the hard skeleton of corals commonly wash up on beaches in areas where corals grow.
The construction of the shell-like structures of corals is aided by a symbiotic relationship with a class of algae, zooxanthellae.
Typically a coral polyp will harbor particular species of algae, which will photosynthesise and thereby provide energy for the
coral and aid in calcification, while living in a safe environment and using the carbon dioxide and nitrogenous waste produced
by the polyp. Coral bleaching is a disruption of the balance between polyps and algae, and can lead to the breakdown and death
of coral reefs. The skeletons of soft corals such as gorgonians, also known as sea fans and sea whips, commonly wash ashore
in the tropics after storms.
Plankton and protests’ (12c): Plant-like diatoms and animal-like radiolarians are two forms of plankton which form
hard silicate shells. Foraminifera and coccolithophore create shells known as "tests" which are made of calcium carbonate. All
these shells and tests are usually (but in the case of foraminifera not always) microscopic in size.
a
b
c
Figure12. . Other categories of marine animals considered that remains seashells
a.
Dish with beachworn coral pieces, marine gastropod shells, and echinoderm tests
Source: http//en.wikipedia.org/wiki/file: Shells_stones_and_other_curios.jpg
b.
A x-ray photograph of a gorgonian
Source: http//en.wikipedia.org/wiki/file: 1-Gorgone.jpg
c.
Marine diatoms form hard silicate shells
Source: http//en.wikipedia.org/wiki/file: Diatoms_Through_the_microscope.jpg
Conclusion
Fish and other aquatic animal products do not only provide essential nutrients for the body but of several uses.
Apart from the medicinal values and their usefulness in the construction industry of fish products and other animals,
their uses as poultry feed, craft, arts, architectural decorations, traditional use as tools and fish hooks, personal atonements,
cultural and religion significance, horticulture, musical instruments cannot be overemphasized.
There every need to develop the fisheries sector to compliment the oil sector
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