Retorts

Killer Protoctistan

I hate to be a stick in the mud, but I feel I must calm some of the excitement in your "Phantom Algae Kill Fish" [May 1993]. You state that scientists do not yet know whether the alga "is a plant or an animal"! Those scientists shouldn't rack their brains too hard because it is neither.

Like all other "algae" and "protozoa" it is a member of a wonderfully diverse kingdom of life called the Protoctista or, if you prefer, the Protista. Considering that the concept was first promulgated way back in 1861 by the Scottish biologist John Hogg, it is surprising that it has not reached out into the general scientific consciousness.

If you would like more details, I would recommend a skim through a monumental 914-page tome published in 1989 entitled Handbook of Protoctista. Handbook indeed! You almost need a wheelbarrow to transport it.

So, next time you are peering down a microscope and you spot a green cell (surely a plant!) swimming around (surely an animal!) which is also eating things (must be an animal -- but animals aren't green!) remember the Protoctista and your nerves can return to their resting state.

Paul Broady, Canterbury University