Trypanorhynch cestodes from Indonesian coastal waters (East Indian Ocean)
Palm, H.W.
Folia Parasitologica 47(2): 123-134
2000
ISSN/ISBN: 0015-5683 PMID: 10945737 Document Number: 519012
The results of a study of trypanorhynch cestodes of fishes from Indonesian coastal waters off western Java, conducted in 1998, are presented. A new species, Dasyrhynchus thomasi sp. nov., is described and figured from Psettodes erumei. Five species are recorded which all represent new locality records: Tentacularia coryphaenae from Katsuwonus pelamis; Nybelinia africana from an unidentified shark; N. scoliodoni from the same shark; Sphyriocephalus dollfusi also from an unidentified shark; and Otobothrium penetrans (plerocercoids) from Tylosurus crocodilus. All except Tentacularia coryphaenae (reported for the first time from Indonesia) are reported for the first time from the eastern Indian Ocean. Scanning and transmission electron microscopy were used to clarify details of the tentacular armature and surface morphology of T. coryphaenae, D. thomasi and O. penetrans. In T. coryphaenae, hook-like microtriches along the bothridial tegument are embedded in the distal cytoplasm, sometimes showing a split base. The solid tentacular hooks are embedded into a fibrillar, highly ordered tentacular wall. D. thomasi is distinguished by its characteristically shaped bothridia and a triple chainette with winged hooks on the external surface of the tentacle. Tufts of microtriches with ciliated sensory receptors are regularly arranged on the bothridial surface of O. penetrans. They show similarities to sensory receptors reported from other trypanorhynch cestodes. Otobothrium pephrikos is considered a junior synonym for O. penetrans on the basis of these investigations, and the variability of the scolex within the trypanorhynch cestodes is emphasised.