Trochus snails - Trochus sp. - are an active part of the clean up crew. They resemble the size and shape of "turbo astrea" snails, but Trochus have whiskers radiating from their foot. They clean glass and rock, and can be seen moving on the substrate's surface. They rely on film algae for their primary food source. Unlike Astreas, Trochus are more likely able to right themselves if they fall off the glass or rockwork onto the sand.
Todd Gardner (known for his fish breeding skills) shared this image and video with me. It settled out of the plankton in his larval system, and in a week's time it had tripled in size....and he discovered this little nudibranch that has been consuming his hydroid population. A pest eater, how cool is that? Hope to get a better identification of this little guy soon. This tiny beast is 8mm in size.
Photos and video by Todd Gardner
This tiny grazer - Strombus maculatus - is a really nice choice for part of the clean up crew. Stombus snails are very active, cleaning the glass and rockwork all day long. They are rather small, no longer than a maximum half an inch in length, and often breed in our aquariums. Without predation, you can end up with a bunch of strombus to share with other hobbyists. Clear egg sacks will appear on the glass, usually with about four white or beige eggs inside.
On my last visit to the LFS, I came across this beautiful specimen. Astraea undosa, or Wavy Turban Snail. Also called Tikal commonly, they are cold water animals. It is Reef-safe, but it won't live long enough to be worth the purchase, according to some experts. Normal water temperature for these is between 60° F and 70° F. Too bad, because their decorated shell adds so much to the tank! This one has barnacles and a type of peanut worm mounted on its shell.
How would you like a 1" Nassarius snail working the substrate of your reef? This is a Super Nassarius Snail, which come from the Tonga region. I've had a few of them in my tank over the years, and they are very active machines especially at night. I've seen them crawling across the glass when the lights are out, and their foot was closer to 3" in length. Reef-safe.
A snail the size of a lemon, this Tiger Cowrie worked its way through my reef for more than a year. When I first set up my 29g reef, I kept buying these but they didn't live longer than a week. I did discover that they would consume an entire leaf of romaine lettuce within 30 minutes, as they are herbivores. Many years later with a much larger tank, I felt I'd try again. Since the water parameters were far more stable in that tank, and there was more surface area for it to snack upon, it did very well.
Many people ask about a snail or slug with a half-shell on its back. They are called Stomatella, and are fast moving slugs. Their shell is similar to a fingernail in shape, which covers the head and torso of the creature. They are found moving about the rockwork especially at night, and are an excellent part of the clean-up crew. They do breed in our tanks and you may see smaller ones, but I've never seen them reach plague proportions.
These grazers are Reef-safe.
One day I came across these very tiny pods. These are so small they are rarely noticed, but I was dipping some new zoanthids to make sure there were no pests and these little guys came out into the open. After checking with Dr Ron on the Marine Depot forum, he and others identified them as sphaeromatid isopods or Sand Skaters. They can zip around quickly and are roughly the size of a pin head. If you can view them from the side, their shell raises up like a pyramid.
When I bought caulerpa (macro algae) once, this tiny 1/4" bright green worm enjoyed crawling all around my refugium. Night after night I watched him explore, snack on the macro, and grow. Little did I know how voracious the Sacoglossa - Oxynoe viridis - slug's appetite was! It would seemingly bite into the stalk with fang-like teeth, causing the plant to 'bleed' out and die. It will rip off branches, which is be fine if those have time to grow anew, but this one guy easily outpaced the plant.
Rotifers are pretty much the smallest food hobbyists can grow, and you'll need a starter culture which is available online from Florida Aqua Farms. Rotifers are tiny specks of dust basically. In the image above, there are hundreds if not a few thousand rotifers that gathered along the edge of a petri-dish. Video would have been a better choice as they are just too small for my camera to photograph accurately. Rotifers need phytoplankton to live, and this must be provided daily.