ISSUE 32 April-June 2011
AQUATIC INVASIVE SPECIES NEWS IN A NUTSHELL Joan Cabreza, Editor
This newsletter focuses primarily on Western U.S. and aquatic issues, but it also contains terrestrial, national, and international news of interest. Contents do not necessarily reflect views of the PSMFC. We welcome questions, comments, and news items; to submit these, or to subscribe/unsubscribe, contact the Nutshell editor at
Something To Ponder
Just What We Need: Another Adaptable Omnivore Being Shipped All Over the Country. An article in the Santa Barbara Independent on Triops (Triops longicaudatus), also known as the “dinosaur shrimp” is a bit scary. Triops are sold as educational “pets,” and while they haven’t been on the market as long as ant farms and Sea Monkeys, they’re quickly becoming more popular. Like brine shrimp, Triops are crustaceans, but unlike the brine shrimp, they easily reach two-and-a-half inches long. Triops have three little eyes, which is how they got their name. These are truly ancient animals; they have changed little in the last 200 million years,
which is why they’re nicknamed “living fossils”. And what has made Triops so successful for all these years? They’ve become extremely well-adapted to living in little temporary ponds (AKA vernal pools, a rare wetland type). Usually during winter and spring, rain fills these pools and the Triops eggs hatch. They grow rapidly, and can reach two inches long in just a few weeks, molting their exoskeleton several times in the process. They’re omnivores, so they eat almost anything, from algae to brine shrimp, insects, and sometimes even their own siblings. After quickly reaching maturity, they lay eggs. They die when the water disappears, but can potentially live for about 50 to 90 days if water remains. The eggs remain in the dirt after the pond dries up, waiting for the next rain. Triops eggs can endure harsh conditions and wait a long time before they spring to life in their temporary habitat. The eggs can withstand freezing and temperatures over 200 degrees Fahrenheit for over half a day, and can normally survive in their dormant state for up to 20 years. (!) But because they’re so adapted to living in temporary water, the eggs need to completely dry out before they can hatch; they won’t hatch in a 1 permanent body of water. Their amazing lifecycle makes Triops one of the few species adapted to short-lived pools. The article states “[they are]... a true delight to watch grow and change over the span of several weeks. Moreover, understanding how the eggs’ prolonged dormant state is achieved may help researchers better understand how we can control the unwanted growth of our own cells, such as in cancer.” (Excerpted from ‘Ant farms and sea monkeys’, in the Santa Barbara Independent, April 11).
[Ed Comment: After extolling the virtues of how adaptable these things are, the article then “helpfully” tells us all where to order them. These things ARE rather cute…so, unlike tiny brine shrimp, it will probably much harder for owners to dispose of them responsibly when they get tired of them. Just what we need: another adaptable omnivore being shipped all over the country, where it can eat near the base of the food chain. Is this really something anyone should be promoting? We have already seen the damage that crayfish and other crustaceans have done when they are released by well-meaning owners. Has anyone evaluated this animal? Maybe states should take a good look at this one. ]
Successes & Lights at the End