Abstract
Four suctorian ciliates,
Cyclophrya magna
Gönnert, 1935,
Peridiscophrya florea
(Kormos & Kormos, 1958) Dovgal, 2002,
Heliophrya rotunda
(Hentschel, 1916) Matthes, 1954 and
Dendrosoma radians
Ehrenberg, 1838, were collected from a freshwater lake in Ningbo, China. The morphological redescription and molecular phylogenetic analyses of these ciliates were investigated. Phylogenetic analyses inferred from SSU rDNA sequences show that all three suctorian orders, Endogenida, Evaginogenida, and Exogenida, are monophyletic and that the latter two clusters as sister clades. The newly sequenced
P. florea
forms sister branches with
C. magna
, while sequences of
D. radians
group with those from
H. rotunda
within Endogenida. The family Heliophryidae, which is comprised of only two genera,
Heliophrya
and
Cyclophrya
, was previously assigned to Evaginogenida. There is now sufficient evidence, however, that the type genus
Heliophrya
reproduces by endogenous budding, which corresponds to the definitive feature of Endogenida. In line with this and with the support of molecular phylogenetic analyses, we therefore transfer the family Heliophryidae with the type genus
Heliophrya
to Endogenida. The other genus,
Cyclophrya
, still remains in Evaginogenida because of its evaginative budding. Therefore, combined with morphological and phylogenetic analysis, Cyclophyidae are reactivated, and it belongs to Evaginogenida.