Wednesday, October 6, 2010

Spike, our Purple Tuxedo Sea Urchin

The algae problem seems to be s.l.o.w.l.y. going away. I'm still doing the 20% weekly water changes (at which point I vigorously scrub all the algae away with a toothbrush and much elbow grease) but it seems like less and less algae re-emerges each week. I only feed the fish once a day now. They seem to have adjusted just fine. In addition, the lights come on later in the morning (I don't get to look at the tank until evening anyway) so the total light period is shorter. Less food and less light = less nutrients for algae to grow. In addition, I added a few more snails and...... (drumroll, please)

A sea urchin!
These guys are the ultimate janitors of the saltwater tank. They are omnivores and eat any debris and algae left gumming up the tank. In the wake of the sea urchin's path is a blinding white streak of clean rock. It looks like someone took an army knife and scraped the rock clean! I LOVE it! Sea urchins are the "canaries" of the saltwater aquarium. At the first sign of less-than-perfect water quality, they begin shedding spines. If your sea urchin looks sickly, it's time for a water change. STAT! Some can quickly outgrow the tank and become predatory so do some research before selecting a species (from what I've read, pencil urchins are not reef-safe while the ones with long spines live on reefs in the wild and do well in aquarium settings as well). In addition, they love ALL algae, including coralline algae that we all work so hard to grow. Keep in mind, you may need to supplement your urchin's diet with seaweed to keep him from eating you out of house and home.

Spike is a Purple Pincushion Urchin, also called a "tuxedo" or "collector" urchin, since it gathers debris on the tops of its spines as it plows over the rocks, walls, and substrate, looking for food. He is really fun to watch. He crawls over everything with thousands of little feet! I absolutely love this guy.


  1. Sounds like a very interesting critter to have... I saw one another day at a LFS, your post made me think of getting one. Post pictures of him please when you get a chance.


  2. I'm looking forward to see a photo of your new aquisition.
    What a COOL aquarium!

    Sharon Morganti :-)