Tetraphyllidean metacestodes of teleosts of the Great Barrier Reef, and the use of in vitro cultivation to identify them

The tetraphyllidean metacestode diversity of 310 teleost fishes, including 87 species from 31 families, was examined from Heron Island, The Great Barr ier Reef, Australia. Eleven metacestode 'types' were identified with the us e of light microscopy. Host-specificity varied greatly among metacestode ty pes. Incorporation of in vitro cultivation allowed generic identification f or some types. Types 1 and 2 belong to Uncibilocularis Southwell, 1925, and have triloculate bothridia and one pair of Forked hooks with unequal prong s; Type 3 has quadriloculate bothridia. Hook development was insufficient t o determine in which genus, Acanthobothrium van Beneden, 1849 or Callioboth rium van Beneden, 1850, this type may belong. Type 4 has unilocular bothrid ia with simple edges and belongs to Anthobothrium van Beneden, 1850. Type 5 has multiloculated bothridia which are invaginated within pouches. This ty pe belongs to the Rhinebothriinae although its generic identity cannot be d etermined. The bothridia of Type 5 everted within 24 hours of in vitro cult ivation and revealed the presence of two forms, one having 48 loculi per bo thridium, the other 72 per bothridium. In vitro studies provide additional support for existing theories of onchobothriid scolex development.