SPHAERECHINORHYNCHUS MACROPISTHOSPINUS SP. N. (ACANTHOCEPHALA, PLAGIORHYNCHIDAE) FROM LIZARDS, FROGS, AND FISH IN THAILAND

Sphaerechinorhynchus macropisthospinus sp. n. (Acanthocephala: Plagior hynchidae: Sphaerechinorhynchinae) is described from females with ovar ian balls obtained from the house gecko, Hemidactlyus-frenatus, and fr om 2 species of frogs, Kaloula pulchra and Microhyla sp. collected in the Doi Suthep-Pui National Park, suburban Chiang Mai, Thailand. One u nidentified juvenile female now assigned the same species (this paper) was previously reported from the body cavity of the murrel fish, Ophi cephalus striatus, also in Thailand. For a parasite that probably matu res in snakes, the above represents an unusual assortment of paratenic host taxa that sheds some light on the possible biology of these unus ual acanthocephalans. The new species is distinguished from the 3 othe r known species of the genus by having the largest number of proboscis hooks per row (9: 3 anterior rooted hooks and 6 spines) with the thir d (posteriormost) hook being the largest, among other features.