OCEANIA Marine Educators Association

OCEANIA Marine Educators Association

Friday, May 13, 2011

Cool Plankton

Aloha,

Thought I would start to add in the marine life info posts I do for my volunteers. This week it is about a type of plankton.

Students are often startled when I tell them that the animal they are looking at in their samples is Lucifer. Well to be more specific, it is just a planktonic shrimp in the genus Lucifer. But yes, this is a very grandiose name for a creature less than an inch long.

Students can only get a bit of the shrimp into view at a time. Usually  they get a couple of the wildly kicking legs which are wrecking havoc with the rest of their sample. I help them follow the body up to the stalked and impressive eyes to make it more recognizable.

Shrimps of the genus Lucifer are characteristic of warm tropical ocean waters. They are one of the very few decapod (10 legged) crustaceans that are permanent members of the planktonic community. They do not settle out to become larger bottom dwelling shrimps or crabs - our more common "decapods" (Note - the 10 legs include the claws - take a count next time you get crab at a restaurant to make sure you were not cheated).

Lucifer spp. are predators and possibly omnivores eating other plankton they encounter. Like most plankton, they are relatively short lived, probably 30 - 40 days.

The name for the group comes from a description of "luminous" (bioluminescent) plankton by one J.V.Thompson in the year 1829. As noted in the ever popular World Register of Marine Species (that would be WoRMS), the original reference was: "Thompson, J.V. 1829. Zoological researches, and illustrations; or, natural history of nondescript or imperfectly known animals, in a series of memoirs, illustrated by numerous figures. Memoir 3. On the luminosity of the Ocean, with descriptions of some remarkable species of luminous animals (Pyrosoma pygmaea and Sapphirina indicator) and particularly of the four new genera, Noctiluca, Cynthia, Lucifer and Podopsis, of the Shizopodae. Pages 37-66, plates 5-8. Cork: J. Hennessy, French Church Street Press."

In this case, the term lucifer does not refer to Satan, but more directly to the Latin translation of the the word which means "light-bearer," the name given to the morning star, Venus. Attachment of the term to Satan is misplaced, but I leave that to the biblical scholars among my readers. In any case, it is always a great find in our plankton samples.

Regards,

Mark Heckman
Hawaii Institute of Marine Biology

For more nice images of a Lucifer species off Australia, check out the Guide to the Marine Zooplankton of south eastern Australia. This is where the above image came from.

Other References:
Growth, reproduction and feeding behavior of the planktonic shrimp, Lucifer faxoni Borradaile, off the Texas coast. Wen Y. Lee1, Makoto Omori2 and Robert W. Peck. Journal of Plankton Research. 1991.