Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in the form of light emission. Fireflies, anglerfish, and other creatures produce the chemicals luciferin (a pigment) and luciferase (an enzyme).

1. BIOLUMINESCENCE

2. 1. Bioluminescence is the production and emission of
light by a living organism.
2. Its name is a hybrid word, originating from the Greek
bios for "living" and the Latin lumen "light".
3. Bioluminescence is a naturally occurring form of
chemiluminescence where energy is released by a
chemical reaction in the form of light emission.
Fireflies, anglerfish, and other creatures produce the
chemicals luciferin (a pigment) and luciferase (an
enzyme).
4. The luciferin reacts with oxygen to create light. The
luciferase acts as a catalyst to speed up the reaction,
which is sometimes mediated by cofactors such as
calcium ions or ATP. The chemical reaction can occur
either inside or outside the cell.

3. 5. Bioluminescence occurs in marine vertebrates
and invertebrates, as well as microorganisms
and terrestrial animals. Symbiotic organisms
carried within larger organisms are also known
to bioluminescence.
•6.Ninety percent of deep-sea marine life are
estimated to produce bioluminescence in one
form or another. Most marine light-emission
belongs in the blue and green light spectrum,
the wavelengths that can transmit through the
seawater most easily. However, certain loose-
jawed fishes emit red and infrared light and the
genus Tomopteris emits yellow
bioluminescence.

4. 6.Non-marine bioluminescence is less widely
distributed, but a larger variety in colors is seen.
The two best-known forms of land
bioluminescence are fireflies and glow worms.
Other insects, insect larvae, annelids, arachnids and
even species of fungi have been noted to possess
bioluminescent abilities.

5. BIOLUMINESCENT ANIMALS
Jelly fish
Marine worm Tomopteris
sp. annelid (segmented)
worm

6. 1. Dinoflagellates are the commonest cause of
luminescence in the surface water of the seas,
especially in summer and in warm waters. Most (but
not all) bioluminescent species are heterotrophs:
Protoperidinium, Noctiluca . In the Firth of Clyde,
Tett (1971) measured a seasonal cycle of spontaneous
luminescence, which correlated well with numbers of
luminescent dinoflagellates.
2. Ctenophores (comb-jellies) - emit bright flashes of
light.

7. • Cephalopods - mesopelagic squid in particular have
well-developed light organs, some self-illuminated,
other using symbiotic bacteria; a few species emit
luminescent ink.
• Polychetes – marine and terrestrial oligochaetes-
Eisenia – a terrestrial earthworm on iritation eject
luminous slime from oral, anal, and dorsal pores.
Polychaetes Chaetopterus exhibits luminosity.
• Arthropods -Crustacea - e.g. euphausiids (krill) have
10 complex light-emitting organs, or photophores,
under nervous and hormonal control. Deep sea
shrimps, Sergestes, light passes from anterior to
posterior. Among insects fire fly.

8. Photinus – fire fly

9. •Molluscs - certain clams, bivalves,certain nudibranchs, sea
slugs ,Octopus
•Bolitaenidae
the order Teuthida
•Colossal Squid
•Mastigoteuthidae
•Sepiolidae
•Sparkling Enope Squid
• Vampire squid
•Urochordates: Salps - flashes of light. Salps are mostly
small, but colonial tunicates Pyrosoma can grow to 1m, and
form dense patches, which light up when illuminated by a
searchlight.

10. LUMINOUS ORGAN
Means light producing organs , they differ with the number and
locations
•In beetles . Mostly lampyridae much diversity of the location of
the luminous organs amongst the male , female and larvae
example:- 1. Photinus
•Single pair in 6th segment of abdominal = male Photinus
•Single pair in 7th segment of abdominal = female Photinus
•Single pair in 8th segment of abdominal = in larval stages of
Photinus
2. Bolitophila = tip of the four malpighian tubules
3. Platyura = caudal end

11. STRUCTURE OF LUMINOUS ORGAN
• Firstly scientist SMITH in 1963 described the anatomy of luminous
organ in Photinus
 PHOTOCYTE = light organ cells which are lying just beneath the
epidermis and backed by several layers of the cells called dorsal layer
cells.
• They are arranged in cylindrical from to the cuticle and richly
supplied with the tracheae and nerves .
• Photocyte cells packed with photo granules , these are LUCIFERIN
and rich with MITOCHONDRIA
• Dorsal cells contain urate forming a reflecting layers .

12. DIFFERENT COLOUR PRODUCED BY THE
LUMINOUS ORGAN
The colour of the light produced by the insects varies with
species
Lampyris, Photinus = yellow green light
Bolitophila = blue green light
Fulgora = white light
Phrixothrix = at thorax and abdomen region green
light , and red light on head.

13. MECHANISM OF LIGHT PRODUCTION
•Basically light is produced by the oxidation of lucifernin . In the
presence of the enzyme luciferase .
• Luciferin is first activated by ATP in the presence of magnesium and
luciferase to produce adenylluciferin .
•the adenyl-luciferin is then oxidised by an organic peroxide , again in
the presence of luciferase , to from so called excited
adenyl-oxylucifernin ,which decays spontaneously to low energy
adenyl-oxylucifernin with the production of light .the energy for this
process is obtained directly from the oxidation process, not from the
ATP and it is released in one large step .the radiation is very efficient,
about 98% of the energy involved being released as light . The low
energy adenyl-oxylucifernin produced inhibits further reaction ,
probably by binding with luciferase .

14. The pyrophosphate however removes the inhibition .
When the light organ is stimulated by a nerve , the
acetycholine released at nerve ending reacts with ATP
and co-enzyme so yield pyrophosphate .
The pyrophosphate diffuse to the photo cycle granules
and stimulates the production of lights by removing the
inhibition of luciferase. During the reaction in the
photocyte more pyrophosphate is released and this may
spread through the cell , extending the reaction . The
chemoluminescence reaction is given diagram

15. Nerve
impulse
Terminal
process acetylcholine
Acetic acid +
choline
ATP + coenzyme A
Adenylic acidAcetyl- coenzyme A + pyrpphosphate +
Hydrolysis
Inhibits luciferaseFree luciferase
Luciferin
+
ATP
Adenylluciferin
+
pyrophosphate
Removes inhibition
Adenyloxy
luciferin
Oxyluciferin
+
Adenylic acid
Stored as waste in
dorsal layer cells
These reactions
normally
prevented by
inhibition of
luciferase
Excited
adenyloxy
luciferin
Light
Mg ++

16. Adaptations and significance of
bioluminescence
•Attraction
1.Bioluminescence is used as a lure to attract prey by
several deep sea fish such as the anglerfish. A dangling
appendage that extends from the head of the fish attracts
small animals to within striking distance of the fish.
2.Some fish, however, use a non-bioluminescent lure.
The cookie cutter shark uses bioluminescence for
camouflage, but a small patch on its underbelly remains
dark and appears as a small fish to large predatory fish
like tuna and mackerel swimming beneath it. When
these fish try to consume the "small fish", they are bitten
by the shark, which gouges out small circular "cookie

17. 3. Dinoflagellates have an interesting twist on this
mechanism. When a predator of plankton is sensed through
motion in the water, the dinoflagellate luminesces. This in
turn attracts even larger predators which will consume the
would-be predator of the dinoflagellate.
4.The attraction of mates is another proposed mechanism of
bioluminescent action. This is seen actively in fireflies,
which use periodic flashing in their abdomens to attract mates
in the mating season. In the marine environment this has only
been well-documented in certain small crustaceans called
ostracod. It has been suggested that pheromones may be used
for long-distance communication, and bioluminescence used
at close range to "home in" on the target.

18. Certain squid and small crustaceans use bioluminescent
chemical mixtures or bioluminescent bacterial slurries in
the same way as many squid use ink. A cloud of
luminescence is expelled, confusing or repelling a potential
predator while the squid or crustacean escapes to safety.
Every species of firefly has larvae that glow to repel
predators.
•Communication
Communication between bacteria (quorum sensing) plays a
role in the regulation of luminesence in many bacterial
species. Using small extracellularly secreted molecules,
they are able to adapt their behavior to only turn on genes
for light production when they are at high cell densities.

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