Abstract
The morphology and phylogeny of two new sessilid species,
Zoothamnium weishanicum
n. sp. and
Epicarchesium sinense
n. sp., two insufficiently known species,
Zoothamnium arbuscula
Ehrenberg, 1831
and
Zoothamnium hentscheli
Kahl, 1935
, and a well-known species,
Carchesium polypinum
(Linnaeus, 1767)
Ehrenberg, 1838
, collected from freshwater habitats of China, were investigated.
Zoothamnium weishanicum
n. sp. is characterized by its inverted bell-shaped zooids, double-layered peristomial lip, alternately branched stalk, and two different-length rows in infundibular polykinety 3 (P3).
Epicarchesium sinense
n. sp. is recognized by its asymmetric-pyriform zooids, single-layered peristomial lip, conspicuous cortical blisters on the pellicle, dichotomously branched stalk, and P3 containing one short inner row and two long outer rows. Based on previous and newly obtained data of the three known species, improved diagnoses and redescriptions are provided including, for the first time, data on the infraciliature of
Z. arbuscula
and
Z. hentscheli
. In addition, we analyzed the phylogeny of each species based on SSU rDNA sequence data.