Lights in the sea?

[EmicMalta]

a year ago I was watching a documentary about cattle fish. A technique used by lots of fish to catch their prey is to spread this liquid in the sea. In the video was showing a cattle fish hunting shrimps. She puts this liquid in the hunting area and to feel the movement of a shrimp its really hard, but by these flashes she can "see" it and actually catch it. They where saying that lots of fish that hunt eat at night use this thing. Infact one of the beads with night fishing is exactly the same thing what I said above.

[148148]

Also if your diving at night with a torch and swoosh your hand around they will glow more as it stirs them up

[Tracina]

http://www.youtube.com/watch?v=SWgfSELnzog

Copy and Paste... this link is awsome!! She is the world expert on the topic (at the moment ; )

This is what I study!!!:
The "liquid" you are referring to is kept in the light organs of Cuttle fish and Squid. The luminescence you observe is actually produced by bacteria!!! In fact, the Cuttle fish grows these bacteria within its light organs and "squirts" them around when night-hunting begins. The hunting technique is pretty much the one described by EmicMalta. Two main species of marine luminescent bacteria are called Vibrio fischeri and Vibrio harvey. I study them for my PhD in Ireland as their luminescence-producing mechanism is very interesting. When at low population density, these bacteria are not capable of producing "light", only when these bacteria reach a high population density (high numbers) they communicate with each other using small diffusible molecules and activate fluorescence. The Cuttle fish, some squid, and several other marine creatures have, over the course of milions of years, learned to use this property (a sort of symbiosis). So they grow the bacteria in their light organs and allow them to reach that density necessary for them to become luminescent. Then at night, they release them and use them to attract & detect their prey. So basically it's like having a broth of bacteria in the light organs ready to be used!!! Also, 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.

Hope it was interesting,

Tracina

Interesting links

http://www.youtube.com/watch?v=SWgfSELnzog

[Tracina]

I forgot to say that there are other organisms that light up (for example Dinoflagellates) upon contact (when disturbed). Sometimes you even see them at the keel of the boat as it's going through the water at night. These are not bacteria, but "plankton". Again here is an interesting link:

http://www.lifesci.ucsb.edu/~biolum/answers.html

in particular, read "Why do things light up when disturbed, if this just makes them more vulnerable to attacks?" in the How and Why section... very interesting. As EmicMalta suggested, some predators also take advantage of this phenomenom to identify their prey. Check out these interesting videos for a demonstration!

Ciao

Tracina

[fishfinder]

Really interesting. Thanks Tracina

[rammx]

yes tx alot Tracina,,,you answered a very frequently asked question

[MartinB]

Nice one tracina very informative & it explained alot! So the cuttle fish makes that glow..no wonder there is always a scabbard fish around whenever i see it in the winter months  

[Yanyano]

Phosforus is usualy found where there is a stable drainage outlet, it reacts due to compounds and gases which are in the dainage.

[Kevin G]

mela mhuwiex phosforus li jider jixghel fejn imoru ghal hut ahna ax qas bozz tal-gvern ma tezisti lol

[name]

I think you are refering to something like this below.....

What makes a Biobay?

Columbia Encyclopedia: Bioluminescence is production of light by living organisms. Organisms that are bioluminescent include certain fungi and bacteria that emit light continuously. The dinoflagellates, a group of marine algae, produce light only when disturbed.

http://elyunque.com/biobay.html

[caldaland]

very interesting indeed name! thank you.