Happy Phytoplankton Friday! Today’s featured phytoplankton is: Noctiluca.
Noctiluca are large, unarmored dinoflagellates with a kidney or balloon-shaped cell. It does not photosynthesize, so it does not have chloroplasts. Instead, it is a heterotroph that feeds on other organisms by using its plasma membrane to engulf other cells (this process is called phagocytosis). Prey that Noctiluca feed on include diatoms, ciliates, copepod eggs, naupliar stage larvae, and even on fish eggs.
Although Noctiluca retain their two flagella, they are highly modified, not always noticeable, and are not strong enough to readily facilitate locomotion. Instead, Noctiluca control their vertical position by regulating their buoyancy in order to catch their prey. They are less dense than seawater, so they float near the surface. Noctiluca also has a tentacle that it uses to sense and capture prey.
Blooms of Noctiluca can be bioluminescent (although Noctiluca in the Northeast Pacific region are not bioluminescent) and can colour the water bright red or orange. Although it does not produce toxins, it can be considered a harmful algal bloom (HAB) species because of its ability to produce toxic concentrations of ammonium (which may be toxic to fish), deplete oxygen levels in the water, and clog other organisms' gills.
Fun Facts:
The phenomenon of bioluminescence was first noted in the genus Noctiluca, which resulted in its name, meaning "night light.” However, the reaction is now known to occur in several marine species.
Because of the spectacular bioluminescent light show it puts on, the species Noctiluca scintillans is sometimes called “sea sparkle.”
Dinoflagellate bioluminescence is controlled by circadian rhythms and only occurs at night.
Images sources: The Phytoplankton Encyclopaedia Project, University of British Columbia / Biological and Satellite Oceanography Lab, University of California Santa Cruz / BioWeb, University of Wisconsin / The Bioluminescence Web Page, University of California Santa Barbara/ Kin Cheung, AP/The Atlantic / K.B. Padmakumar, Cochin University of Science and Technology
Check out this photo story by one of STA's Tribal Youth Interns, Keet, documenting the experiences of their summer internship. Photos by Angela Hessenius, Muriel Reid, and Will Peterson; Captions by Keet Lorrigan.
A Peek Into the Week of the Tribal Youth Interns: Week 6
1. Naomi and Clare showing off
2. Keet Lorrigan with a bucket of berries.
3. Emily Khor, Keet Lorrigan, and Muriel Reid retrieving sea monitoring equipment.
4. Muriel Reid intently cleaning a sockeye.
5. The STA workforce cleaning Klag bay sockeye.
6. A nice haul.
7. Emily and Danny Khor with Muriel Reed.
You can also see this story on SEATOR's Blog! https://seator.home.blog/2019/08/07/a-peek-into-the-week-of-the-tribal-youth-interns-week-6/
