Night lights of the Caribbean
     Kryptophanaron alfredi



    Fish in the family of Anomalopidae, can be found in the benthic zones of the southern hemisphere and off the coasts of coral reefs.  Kryptophanaron alfredi can be found in several locations in the Caribbean.  One study located the fish near Puerto Rico and Parguera (Haygood et al. 1984). Another study found the fish around the Grand Cayman Island (Colin et al. 1979).  Other organisms that share the same benthic zone habitat include: Odontosyllis phosphorea and Ophiopsila riisei. This fish lives in the Caribbean because the waters contain the most optimal temperatures for its mutualistic symbiosis with the luminescent bacteria.  The bacteria are housed in a light organ which is used for mating and searching for food off the rocks and coral on the reef (Colin et al. 1979).  For more information on the light organ, refer to the adapation page.


Figure 1. Map of Caribbean where Kryptophanaron alfredi inhabits. (Modified by Lynzee Pinkert, 2013).

     The fish of the family Anomalopidae, live in deep waters during the day but surface around 10m-40m at night off the banks of reefs.  They use the tactic of staying in deep water during the day to avoid predators and surface at night to search for food.  According to one study, it could be hypothesized that the fish surface only long enough to fill their stomachs and return to the deep waters to avoid predators and divers.  The Kryptophanaron alfredi eats small aquatic crustaceans like shrimp, copepods and other small fishes.  This study captured fish and found 45 shrimps packed in one of the stomachs of fish collected in the Grand Cayman (Colin et al. 1979).

    Another hypothesis why the fish surface at night can be accounted for by the moon.  As stated before, the fish only surface during the night.  Interestingly, the length and timing of the surfacing could be influenced by the moon (Colin et al. 1979).  One study done in the Cayman Islands found the number of fish that rose to the surface decreased when the moon was blocked by clouds.  Kryptophanaron alfredi is sensitive to the moon’s strong illumination (Colin et al. 1979). 

 Figure 2. Coral reef. Jerry Reid. U.S. Fish and Wildlife Service.

    The best suited environment for the Kryptophanaron alfredi is a habitat that contains both shallow and deep waters.  The fish need shallow waters to feed and to allow their larva to be dispersed throughout the water columns (Baldwin & Johnson 1995).  They need deep waters for their own protection, but also for the protection of their eggs.  (To learn more about their egg and larva, visit the reproduction page.)  K. alfredi can be found in deep waters that contain many rocks, crevices, and caves.  One study of the Cayman Island specimen found their environment to be “characterized by deep erosion channels, undercut ledges, and numerous caves” (Colin et al. 1979).  It is important for their environment to contain these structures for the protection of their young.  The eggs attach to the rocks and caves and are protected from being eaten by predators.  Another organism that uses caves and crevices in their environment for protection is the Enteroctopus megalocyathus (Patagonian red octopus).    

Want to keep reading? Visit our Adaptation page.

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