Bioluminescence

Bioluminescence
Guided By : Submitted By:
Prof. Anjula Porus. Sudarshan Gokhale
Msc Zoology

1. Introduction.
2. Occurrence of bioluminescence.
3. Distribution of bioluminescence organs.
4. Structure.
5. Significance.
6. Conclusion.
Holkar Science College,Indore

Fish posses a number of adaptive structures
which have been evolved to meet special
requirements faced by them.
Most important of them are:
 Electric organs
 Phosphorescent organs
 Poison glands &
 Sound producing organs

 It is the production and emission
of light by a living organism.
 Widespread across marine
zooplankton and micro-nektonic
life.
(BIOS - LIVING,LUMEN - LIGHT)

 Product of a reaction
- Chemical (luciferin)
- Enzyme (luciferase).
Luciferin-indole derivative consisting of
tryptamine,arginine, and isoleusine.

 The most common luciferin is Coelenterazine.
Vargula luciferinCoelenterazine

Luciferin + Luciferase Oxyluciferin,
(emitting light).

 “One of the most important processes in the
ocean, and yet hardly anyone was studying it.”
 These are absent in freshwater forms.
 These mostly the characteristic feature of
midwater and bottom dwelling deep sea
fishes.

 Fishes with luminiscent organs are world wide
in distribution.
 Majority of them are bathy pelagic living at a
medium depth(500-2000).
 In fishes the luminescence is generally blue or
green.

 70% of all species collected from Bermuda
and south atlantic had light organs.
 Systematic survey shows 10-15% of all
marine fish genera contain luminous organs.

1.Results from the presence of luminous
bacteria living on the fish in a symbiotic manner.
2.Arises from the self luminous cells on the
fish,the photophores.

Photobacterium is a genus of gram negative
bacteria in the family vibrionaceae. Members of
the genus are bioluminiscent that is they have the
ability to emitlight.

photobacterium leiognathi photobacterium phosphoreum
Many species, including Photobacterium
leiognathi and Photobacterium phosphoreum
and , live in symbiosis with marine organisms.

 These are associated with diverticulum of
the gut( infect during the larval life).
 Surrounded dorsally and laterally by a
connective tissue reflecting layer.so light
emerges downwards and is refracted by
translucent ventral muscles before passing out
of the ventral region.

 In which the bacterial
organ is situated near the
anus from a gut
diverticulum.
 It is enclosed in a black
epithelium exept
anteriorly.
Eg;Opisthoproctus
Opisthoproctus soleatus

 Where it shines into a long ventral hyaline
light guide surrounded dorsally by reflecting
platelets.
 The boom of the fish being completely flat
light emerges evenly over the whole of this
flattened sole.
 used for ventral camouflague.

Eg;Photoblepharon
 They glow
countinuosly,(can only
hide by a shutter or
rotating them into a
black lined pocket).
Photoblepharon

 In Chlorophthalmus
the light is very much
dimmer than those of
Photoblepharon.
Chlorophthalmus

 Spectacularly
luminescent fish(10^10
bacteria/cm^3!!!!!!).
 Used to search corals
during day time and at
night hunts small
copepods.
Flashlight fish

A number of fish mostly deepsea fish
possess characteristic luminescent organs
namely PHOTOPHORES.

 Similar to eyes
 Having a reflecting layer and capped with a lens.
 Richly innervated and certainly under nervous
control.
 The transmitter commonly is adrenaline or nor
adrenaline(in hatchet fishes it is epinephrine).

In the two images,
 ‘c’ is the light-emitting core
 ‘r’ is the reflector
surrounding it and
 ‘f’ is a filter to give the
emitted light
The light bounces around
until It exists the photophore
through the aperture.
Photophores from the
dragonfish Malacosteus.

 Specialised
gland cells of
the epidermis.
 Show
considerable
variation in
their number
and mode of
distribution.

 Ventral series
of photophores
(camouflague).
 The lateral
photophores
(signalling).
Eg;Lantern fish
Lantern fish

1.SERIAL VENTRAL PHOTOPHORES
 They are large and ventrally directed in shallower
species.
Eg; Stomias and Chauliodus
StomiasChauliodus Holkar Science College,Indore

2.SIMPLE PHOTOPHORES
 In many genera,there are a red fluorescentviolet
pigment like that of serial types but they usually lack
reflectors.
 Very similar to the unpigmented glandulartissue.

 Generally they occur on the lateral and ventral
sides of the body and sometimes in head also.
3.GLANDULAR
LUMINOUS TISSUE
 These patches emit very rapid high
intensity flashes(10per sec).

 Streaks of some glandular
tissue occur (flanks of
Malacostieds).
 It also bears a
camouflague
function(Macropogon). Macropogon

 Arranged as one or two rows extending on
the sides from head to tail(scopelus and
halosauropsis).
 Rarely arranged in transverse bands on the
body(Opostomias).
The ObeseDragonfish,
Opostomias micripnus.
Photophores, or light producing
organs, cover the fish in rows
and below both eyes

ALTERNATIVE FORMS
 One or two suborbital
organs(Opostomias,Micripnus,Scopelus benoitti
and Pachystomias microdon).
Pachystomias microdonHolkar Science College,Indore

 In deeper
species,the organ is
reduced in size
becomes almost
rudimentary(Malacost
eids). Malacosteids
 In all families these have a red flourscnt
violet pigment in the aperture.
 Stimulated by adrenaline injection.

In angler fish:
Looking like something out
of a science fiction movie, the
anglerfish uses a natural lure to
draw its next meal nearer
Large photophores on the elongated first finrays
of pectoral and dorsal fins.

In toad fish porichtheys:
 A large
number of
photophores are
present along
the lateral line.

 Used to increase the
visibility of lateral
photophores.
Eg;Hatchet fish and
Scopelarchus
A Hatchetfish showing off its glow
YELLOW LENSES
ScopelarchusHolkar Science College,Indore

Eg; ophisthoproctus and argyropelecus.
 Difficult to find these fishes from below.
 Cracking of ventral camouflague system using
filtering lenses.
Opisthoproctus ArgyropelecusHolkar Science College,Indore

 Used to circumvent the camouflague of
prey.
 Possess visual pigments absorbing red
light.
Eg;Malacosteus and Pachystomias
 Having large redemitting
photophores underneath the
eye.
RED HEAD LIGHT FISHES

 Illuminates the prey with a light of a
wavelength that the prey can’t detect.
 Retina absorbs around 575nm so they can perceive
redlight(most deep sea fishes - 450-490nm).
 Red reflecting tapetum and increased pigment
density to make up the inevitable loss of sensitivity.

Malacosteus

 Can observe common
red and brown
animals of the middle
depth(which can’t be
illuminated with the
more common blue
emitting
photophores).
Eg;Diaphus
Diaphus

1.Search the prey in the dark
waters.Eg:Anomalops.
2.Attract prey near the mouth.
3.Some times acts as defensive organ.
4.Warning signal for the predatory animal.
5.Recognising individuals of the same
species(schooling).

CONCLUSION
 New species of luminescent fish are discovered
yearly
 But the function and physiology of the light organs
remain more speculation than scientific fact.
 Access difficulties, expensive ship and submarine
cost ,and low funding have hamstrung effect and
our knowledge of bioluminescent fish lags behind.

Thanks

Bioluminescence

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