Chauliodus sloani (E. Widder)


Finding Food
If you are trying to find something in the dark, a flashlight can be very handy. Many animals like this Black Dragonfish (below) have light organs under their eyes that they can use just like a flashlight to help them search for their prey.



Melanostomias bartonbeani

 

(T. Frank)


Many male angler fish are tiny compared to the females. This dwarf male has no bioluminescent lure and in fact must depend on his mate for his food. When they find each other, the male seals the relationship with an eternal kiss. He latches on to her side where his lips actually fuse with her flesh and her blood stream flows into his body providing him with the nourishment he needs to survive. In return, he provides her with the sperm she needs to reproduce. Continue your dive to learn how bioluminescence helps animals defend themselves.

 


WHY THEY MAKE LIGHT

There are so many bioluminescent creatures in the ocean, because their ability to make light helps them to survive. Some use their light to help them find food, some use it to help them find mates, some use it to defend themselves against predators and some, like this Viperfish, use light for all these purposes.



Melanocetus johsonii(E. Widder)


Anglerfish (above) attract their prey to them with a glowing lure that dangles from the end of its fishing pole. When the unsuspecting prey tries to nibble at the tempting bait, it finds itself instantly engulfed in that mouthful of needle sharp teeth.


Finding A Mate

Bioluminescence can also be used to advertise for a mate. Sex signals which send messages like "Eligible female seeks compatible male" can be sent using a special flash code, as fireflies do on land, or light organs can have a very special shape or pattern that is specific to a particular species and allows a member of the opposite sex to recognize a potential mate. For example, this lovely lady (below) is an angler fish with a particularly fancy lure. Although at one time it was thought that each lure was designed to attract special prey, it now appears that the unique shape has evolved to attract a male of the same species who recognizes his future mate by her lure. Below left is a male angler fish.


Oneirodes sp. (E. Widder)

 








 


DR. WIDDER WELCOMES YOU TO COME ALONG WITH HER AS SHE EXPLORES THE GLOWING, SPARKLING, LUMINOUS WORLD OF BIOLUMINESCENCE.