Morphometric and molecular analyses of two digenean species from the mullet: Haplosplanchnus pachysomus (Eysenhardt,
1892) from Vietnam and Provitellotrema crenimugilis Pan, 1984 from the Russian southern Far East
Adults of Haplosplanchnus pachysomus (Eysenhardt, 1829) were found in the
intestine of Liza engeli (Bleeker) from the coastal waters of Cat Ba Island, Ha Long
Bay, northern Vietnam. Additionally, Provitellotrema crenimugilis Pan, 1984 was
discovered in Liza haematocheila (Temminck & Schlegel) from Vostok Bay, Gulf of
Peter the Great, southern Far-East Russia. Data concerning morphology, 18S
rDNA and 28S rDNA of these worms were obtained.The molecular data
confirmed the validity of these species and showed that specimens identified as
H. pachysomus are closely related to specimens of H. pachysomus found in Spain,
and that P. crenimugilis is closely related to Haplosplanchnus purii. Molecular
differentiation of P. crenimugilis and H. purii was 0.92% by combined ribosomal
gene sequences that confirmed species validity. Molecular differentiation
between P. crenimugilis and H. purii, on the one hand, and H. pachysomus, on
the other hand, was much higher, suggesting that the sequence for H. purii in
GenBank is for a misidentified species of the genus Provitellotrema Pan, 1984.