TABLE CONTENTS

Toxocara canis (6.02%), Toxascaris leonina (32.53%), Ancylostoma caninum (3.61%),
Oxynema sp. (1.35%), Rictularia affinis (12.05%), Taenia hydatigena (53.01%), Taenia ovis
(7.23%), Taenia multiceps (4.82%), Echinococcus granulosus (13.25%), Dipylidium caninum
(38.55%), Mesocestoides lineatus (26.50%) and Macracanthorhynchus hirudinaceus
(4.82%).
Findings of Drilonematoidea in Vietnam
Ivanova, E.S. (1), P.V. Luc (2) & S.E. Spiridonov (1)
(1) Center of Parasitology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences,
Leninskii pr., 33, Moscow, 119071, Russia; (2) Museum of Natural History, Vietnamese Academy of Science
and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam
Search of nematodes parasitic in Vietnamese earthworms began 20 years ago. From nearly
200 nominal pheretimoid species (Blakemore, 2006), a quarter was examined including
formalin-preserved specimens from the collection of Dr Thai Tran Bai, Hanoi Pedagogic
Institute, and animals collected alive during our field trips in Vietnam. Fourteen earthworm
species were registered as hosts for Drilonematoidea. Four oligochaete species served as
hosts for more than single nematode species. Amynthas leucocircus (Chen, 1933) collected in
Ba Vi National Park in the Northern Vietnam, were particularly prone to nematode infection:
7 drilonematid and 4 oxyurid species were described from this earthworm species.
Discoveries from Vietnamese pheretimoid earthworms include representatives of
Homungellidae (Homungella and Perodira), Ungellidae (Synoecnema, Siconema, Thainema,
Unicorninema) and Drilonematidae (Adieronema, Iponema, Mesonema). The first family,
Homungellidae, until now was reported exclusively from South East Asia. Ungellid
nematodes are represented in Vietnam mainly by Synoecneminae subfamily which includes
highly specialized parasites lacking male spicular apparatus and found in a state of permanent
copulation. However, recently a new species and genus of the other subfamily, Ungellinae,
was firstly discovered. It is differentiated from the rest of Ungellidae by the presence of a
single strongly developed cephalic hook. In this respect it reminds the genus Homungella but
clearly differs by presence vs lack of spicules and gubernaculum and different shape of
sperm. High diversity of drilonematid nematodes provided by pheretimoids native to Vietnam
allows resolve relationships within their higher taxon, Drilonematoidea. Recently,
phylogenetic analysis based on 18S rDNA partial sequences has revealed an affinity of
species of Ungellidae (Siconema), together with Homungellidae (Perodira) and
Drilonematidae (Dicelis), to the free-living cephalobid genera (Spiridonov et al., 2007).
RFBR support 07-04-9005 Viet_a.
5 th International Congress of Nematology, 2008 228