Journal of the Marine Biological Association of the United Kingdom

Research Article

A Parasitic Association Between a Pycnogonid and a Scyphomedusa in Midwater

C. Allan Childa1 and G. R. Harbisona2

a1 Department of Invertebrate Zoology, Smithsonian Institution, Washington, D.C. 20560, U.S.A.

a2 Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, U.S.A.

The feeding habits and host specificities of the Pycnogonida are poorly known. These usually small, cryptically coloured animals are difficult to observe alive and are mostly collected fortuitously in gross samples taken from trawls and dredges. Any association between the pycnogonids and their food is disrupted in the trawl. Further, the possibility that some of the pycnogonids may have been captured in the water column rather than on the bottom cannot be ascertained from trawl and dredge samples. King (1973) lists only twelve records of pycnogonids actually seen browsing on food organisms. Most occur on hydroids and other cnidarians, and all are from benthic habitats. In more recent papers, Stock reports a pycnogonid seen on a brittle star in the Seychelles (1979), feeding preferences of pycnogonids on benthic cnidarians (1978), and an association between a pycnogonid and a starfish from the Philippines (1981).