The Large Worm Turns… by Ron Shimek[/url]]
Some fireworms often reach quite substantial sizes and aquarists are sometimes astonished to find that their tanks may contain worms over 18 inches (60 cm) in length, and with the diameter of a pencil. Most of these giants are probably individuals of the common Caribbean species, Eurythoe complanata, and are exceptionally diligent and beneficial members of the guild of scavenging animals found in our aquaria. Large Eurythoe individuals are adept at remaining out of sight in the interstices and internal cavities of reef aquarium rock work; it is often only when the tank is being remodeled or broken down that the big worms are found. These worms reproduce well in our systems and they are occasionally seen spawning copious amounts of pink sperm and eggs into the tank waters in a veritable vermous orgy. These spawning events produce a lot of gametes which are consumed by corals, soft corals and other filter feeding animals. Nonetheless, the odds of some reproductive success appear to be quite good, and Eurythoe seems to be able to maintain stable populations in aquaria indefinitely. The reproduction of the smaller fireworms that are also common in our systems, in the genera Linopherus or Pareurythoe, is less obvious, but they also can maintain quite stable and large populations in our systems. Most of the fireworms found in our tanks are in these latter two genera, and these animals occupy burrows in the sediments as well in holes in the rockwork. If not hassled by fish or crustaceans, they may be seen commonly during the day looking for food and doing their other wormy activities. These smaller species may reproduce more frequently by asexual than sexual means as indicated by the abundance of worms that are regenerating either front or back ends. As with the small starfish that are common in some reef aquaria, these worms reproduce asexually by fission, after which both halves produce the missing component.
