Staff from the New England Aquarium recently traveled to Belize as part of a long-term research program run by Aquarium scientist Randi Rotjan, PhD, to monitor coral health near Carrie Bow Cay. Today's post by Giant Ocean Tank diver Sean Marden is part of a series about these research efforts.
We ended our trip to Belize with a very exciting experience — a night dive! This was an excellent opportunity to observe the differences in the reef community during different times of day. Animals that are more active during the day are called diurnal and those that prefer night are nocturnal.

An example of unique nocturnal behaviors can be seen in some species of parrotfish which create a mucus cocoon around themselves while they lay down to rest at night. The function of this cocoon is not completely understood but the mucus may act to repel ectoparasites while the parrotfish rests (Fishmucous cocoons: the ‘mosquito nets’ of the sea - Grutter et. al. 2010). 

During our dive I found this terminal phase stoplight parrotfish tucked up against the reef.

Many species of invertebrates also become more active at night. For animals that don’t rely on vision to hunt there is no need to hunt during the day when potential predators might be lurking. Basket stars and corals are generally much more active at night.

In the video above a basket star has captured a small red worm and is beginning to pull it in towards its mouth and then a coral colony can be seen extending it's polyps searching for food. Stony corals are located in the phylum Cnidaria along with jellyfish and sea anemones. When corals extend their polyps you can really see the resemblance!

My time in Belize was a great opportunity to observe these animals in their natural habitat and I can't wait to get back there soon!

Catch up on previous trips to Belize—lots more amazing pictures!

• Researchers most recently visited this past spring
• See the beauty of hermit crabs and ride out a tropical storm during their 2013 trip
• Learn more about threats to corals, plus signs of a late-night visitor to Carrie Bow Cay, in 2012
• See what other researchers are up to at the research station in 2011
• And read the exciting post where the marine protected area was announced in 2010