Ref ID : 4911
Takashi Ota and Akira Taniguchi; Conjugation in the marine aloricate oligotrich Pelagostrobilidium (Ciliophora: Oligotrichia). Europ.J.Protistol. 39:149-160, 2003
Reprint
In File
Notes
Morphogenesis and nuclear events during conjugation have been investigated for the aloricate oligotrich Pelagostrobilidium sp. using cytological staining methods. While several similarities between Pelagostrobilidium and sister groups (hypotrichs and stichotrichs) reported previously were recognized in the preconjugation behaviour, conjugation type and general nuclear division patterns, significant differences were found between them in the behaviour of oral and somatic ciliatures. In Pelagostrobilidium there was no reorganization in the somatic kineties during conjugation, in addition, it showed a very simple pattern of reorganization in the oral ciliature, which was very similar to stomatogenesis in asexual reproduction. A replacement oral apparatus was completed during the conjugation process and it very quickly replaced the old adoral zone when the conjugants separated. A noteworthy fact is that most of the parental adoral membranelles of Pelagostrobilidium persisted and were active during the entire conjugation period in spite of the loss of functional feeding organelles such as the cytostome and paroral membrane. The need to retain locomotion throughout the entire life cycle might be one of the adaptive features of oligotrichs required to occupy a certain niche in oceanic waters. The relatively short duration of the conjugation process (5.6 hr) of Pelagostrobilidium is also likely to be important for life in oceanic waters.