Night lights of the Caribbean
     Kryptophanaron alfredi



    Kryptophanaron alfredi is a luminescent fish.  There are many bioluminescent organisms that can be found throughout the world including bioluminescent algea (ie. Gonyaulax polyedra), bioluminescent insects (ie. Photinus ignitus), bioluminescent dinoflagellate (ie. Noctiluca scintillans) and many more.  There are many ways that organisms can produce their luminescent feature.  The Kryptophanaron alfredi gets its luminosity from its mutualistic relationship with bacteria part of the genus Photobacterium, Lucibacterium, and Vibrio (Herish, 1982).  Another example of a bacteria that is part of the Vibrio genus is the Vibrio salmonicida.  The bacteria provide the light source that helps the Kryptophanaron alfredi find food, in return Kryptophanaron alfredi provides protection for the bacteria.   In the family Anomalpidae, flashlight fish, bacteria live within light organs that are made primarily of tubules, and bacteria are found specifically in the lumen of the those tubules (Haygood, 1990). 

    In Kryptophanaron alfredi, the bacteria are found in light organs, called photophores, in the fish that are located near the head of the fish and are blue-green in color, similar to the color of light the bacteria emits (Colin et al., 1979). The photophores are able to block the light emissions by either blocking the light with a black sheet like structure that moves up over the organ from the bottom of the organ, or by rotating the organ so the light does not shine outwards (Herrish, 1982). 

The bacteria that live in Anomalopidae can move in and out of the photophore through pores that are located in the surface of the photophore (Haygood, 1990).  The surface of the photophore is thin and relatively transparent which makes it easier for the transportation of the bacteria across the surface (Colin et al., 1979).  The bacteria in the light organ produce an enzyme that produces light and provide the light for the Kryptophanaron alfredi (Haygood 1990).

Copepod, trasparent blue
    The Kryptophanaron alfredi finds its food mainly in the depths of the ocean where little sunlight is reached.  It is thought to use its luminosity to find food. During the day the fish receeds to deeper locations, and continues to use its light to see its prey (Colin et al., 1979).  The Kryptophanaron alfredi eats mainly shrimp and copepod which are located in the benthic zone (read more in habitat) (Colin et al. 1979).  The bacteria provide the light source that helps the Kryptophanaron alfredi find food.

                                                          Figure 1. Copepod. Kils 2004.

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