Introduction to Zoanthid Eating Spiders:

Zoanthid Eating Spiders are marine arthropods of class Pycnogonida also called Pantopoda or Pycnogonid. There are over 1300 known species of Pycnogonida and it seems more than one type feed on Zoanthids. There may be other types of Pycnogonida that feed on other types of corals. This parasite does not run ramped in the marine hobby because they reproduce sexually, not asexually.

What Zoanthid Eating Spiders look like:

These sea spiders are typically eight legged, but may have other appendages that resemble legs. These appendages are used in caring for young and cleaning as well as courtship. The average size is about 5 mm across. The Zoanthid spider that we look for is very hard if not almost impossible to see as the spider crawls inside of the polyp as it closes.  However, there are times when the spider's legs are exposed outside of the closed polyp, as shown in the picture below.



Life Cycle of Zoanthid Eating Spiders:

Sea spiders reproduce sexually, with the male caring the eggs. Sea spiders are not hermaphroditic, meaning they do not have both male and female reproductive organs. This is one of the reasons that we do not see them spread fast through the aquarium hobby.


of Zoanthid Eating Spiders: A quarantine tank is the easiest way to prevent these ugly little reef critters from destroying your Zoanthid based reef tank. Ideally Zoanthid corals should be left in quarantine for 3 months. During the quarantine time you should view the coral on a daily basis and look for spiders. Remember that Zoa Eating Spiders like to stay hidden in the polyp mat. Whether or not quarantine is an option, a dip in CoralRx is highly suggested.

of Zoanthid Eating Spiders: Treatment should be done in a quarantine tank. First step is to move the effected corals to a quarantine tank; the quarantine tank should have good light and water flow. Setup your quarantine tank, then take your coral out of the main tank and dip it in Coral Rx. While the coral is in CoralRx take a turkey baster, and blast the coral with the dip. Making sure it is getting in between the polyps and the underside of the coral. Do this for approximately 5 - 10 minutes. After 5 - 10 minutes, remove the coral and discard the coral dip.  Do not reuse the coral dip as parasites may release toxins.  Rinse coral with clean saltwater and return to quarantine tank. Repeat every 4-8 days till no more Spiders are found. Leave the coral in your quarantine system for an additional 3 months before moving back to your aquarium. Additionally, adding wrasses to your quarantine tank will also aid in treatment of Zoanthid Eating Spiders.