Bioluminescent organisms can create their own light! There are many weird and wonderful bioluminescent creatures in the ocean. Some emit light as a predatory tactic, like the anglerfish, which has a light-emitting photophore that protrudes from the top of its head. The anglerfish has a symbiotic relationship with bioluminescent bacteria that collect on the photophore and help lure prey towards the fish’s mouth. This is helpful in the darkness of the deep sea where food is scarce and hard to find.
Other organisms use bioluminescence to defend themselves. Dinoflagellates are a type of phytoplankton that flash a blue-green light when they get agitated by waves or predators at nighttime. This light can startle and distract the phytoplankton’s predators, or it can act as a burglar alarm that attracts bigger predators to come to the feeding site. Sperm whales are known to linger around places with lots of these bioluminescent organisms because their glowing alerts the whale that there is prey in the area.
Next time you are by the ocean at nighttime, try splashing around in the water and see if these dinoflagellates will light up for you!
The Garibaldi, or Hypsypops rubicundus, is the official California state marine fish and is protected in Californian coastal waters. They are found in shallow water up to 100 ft in depth usually in rock reefs and rocky sea bottoms. This species of damselfish inhabits the waters of the Pacific Ocean from Monterey Bay, California to Baja, California along rocky coastal reefs and among kelp forests. They are especially common to the more southern Channel Islands.
Extremely visible by their bright orange coloration, adult fish may reach up to 15 inches in length. Juvenile garibaldi fish are yellow-orange with iridescent blue spots and which signify to adults in the area that they are not a threat. As they grow, the blue spots disappear until they are solid orange. These fish are not considered mature until five or six years old and are about eight inches long. They feed on various sponges, algae, and invertebrates including tubeworms, nudibranchs, and bryozoans.
Adult male garibaldi carefully construct circular nest sites about one foot in diameter in shallow reef habitats weeding out all organisms except for red algae. The more well-prepared and maintained the nests are, the more likely a female will choose that nest to deposit her eggs for fertilization by the hosting male. As soon as a female has laid her eggs, the male chases her away before she has the chance to munch on any other eggs in his nest. Once the eggs are fertilized, the male continues to guard the nest often warning divers of their close proximity with a loud thumping noises.