New Contribution to the Morphology and Taxonomy of Four Marine ...

146 W. Song et al.
Petz et al. 1995, Wilbert 1995, Song and Packroff 1997,
Berger 1999, Song and Hu 1999).
The current work forms part of a faunistic study of
ciliates in the coastal waters of the north China seas,
which has been carried out for a period of over 10 years.
In this paper, 4 previously known but poorly described
species of hypotrichs, collected from offshore mariculture
waters near Qingdao, China, are redescribed following
examination using modern techniques.
MATERIALS AND METHODS
Sample sites. All samples were collected from mariculture waters
near the coast of Qingdao (Tsingtao, 36 o 08’N; 120 o 43’E), China.
Bakuella agamalievi and Cyrtohymena marina were isolated (6 May
1997) from a semi-closed pond used for mollusc culture (salinity
10-15 ‰). Pseudokeronopsis flavicans was isolated on two occasions
(6 and 12 May 1997) from the same sampling site as above.
Two populations of Holosticha heterofoissneri were collected on
separate occasions (31 March 1995 and 28 October 1997) from an
open scallop (Chlamys farreri) farming pond (salinity 31-32 ‰).
General methods. After collection and isolation, specimens were
maintained in the laboratory for several weeks, either as pure or raw
cultures in Petri dishes, with rice grains as food source for bacteria.
Observations on living morphology were undertaken using Nomarski
optics. Protargol staining (Wilbert 1975) was performed for revealing
the infraciliature and nuclear apparatus. Counts and measurements
were made at a magnification of x1250. Drawings were made with the
help of a camera Lucida. Terminology is mainly according to Foissner
(1982) and Hemberger (1985).
New type specimens. Since no type specimens of Bakuella
agamalievi, Cyrtohymena marina or Pseudokeronopsis flavicans are
known to exist, one neotype slide of protargol impregnated cells of
each species has been deposited in the collection of the Natural
History Museum, London, UK with the following registration numbers:
Bakuella agamalievi, 2001:1z:z8:01; Cyrtohymena
marina, 2001:1z:z8:02; Pseudokeronopsis flavicans, 2001:1z:z8:03.
In addition one paraneotype of each has been deposited in the
Laboratory of Protozoology, Ocean University of Qingdao, People’s
Republic China.
RESULTS
Bakuella agamalievi Borror & Wicklow, 1983
(Figs 1-8, 52-53; Table 1)
Syn. Holosticha manca sensu Agamaliev, 1972
Borror and Wicklow (1983) reclassified this species
but did not give a clear definition; hence we supply here
the species diagnosis based on the present studies.
Improved diagnosis. Marine Bakuella with elongated
body shape, 100-150 x 30-50 µm in vivo; about
30 adoral membranelles; on average, 33 left and 43 right
marginal cirri; 4-7 frontoterminal, 4 frontal, one buccal
and 4-7 transverse cirri; 9-13 pairs of midventral cirri
distributed mostly in frontal area; 3-6 ventral rows with
3-5 cirri each; consistently 3 dorsal kineties; numerous
macronuclei; cortical granules grouped in short rows;
one contractile vacuole in anterior 1/3 of cell.
Morphological description. Body shape generally
constant, length to width ratio about 3:1 with both ends
well rounded; cell margins almost parallel with slight
bulge in middle portion (Fig. 1). Buccal field about 1/3 to
2/5 body length (Fig. 1). Pellicle rigid, cortical granules
colorless or slightly greenish when observed at low
magnification, about 0.8 µm across, typically grouped
together and sparsely arranged in short rows on both
ventral and dorsal sides of cell (Figs 2, 3, 53). Cytoplasm
colourless to grayish, usually containing numerous shiny
globules (2-5 µm in diameter), which render the cell
completely opaque. Food vacuoles large, usually several
in number, and containing flagellate, small ciliates or
bacteria. Contractile vacuole (CV) situated near left
border about 1/3 to 2/5 of the way down the body (Figs
1, 3). Pulsation interval rather long (up to 5 min). About
50 ellipsoid macronuclear nodules, each ca 3-5 µm long
and containing several large nucleoli; micronuclei globular,
only recognized after protargol staining (Fig. 8).
Locomotion moderately fast, crawling on substrate,
sometimes jerking back and forth.
Adoral zone of membranelles about 1/3 of cell length
with distal end only slightly curved towards right border.
Bases of membranelles ca 7-8 µm in length. Cilia of
membranelles 15-20 µm long. Undulating membranes
relatively long, slightly curved and noticeably crossed
(Figs 4, 7).
Somatic ciliature typical of genus. Three slightly
enlarged, and one smaller, frontal cirrus arranged in
anteriormost portion of frontal area; cirri about 20 µm
long. One buccal cirrus near anterior 1/3 of undulating
membranes (Fig. 4). Mostly 6 frontoterminal cirri relatively
fine, located at anterior terminus of right marginal
row (Figs 4, 7). Midventral rows composed of closely
spaced oblique pairs of cirri and extending to about the
level of the cytostome (Fig. 7). Posterior to these
midventral rows are (usually) 4-5 ventral rows (arrows
in Fig. 7) each with 3 to 5 cirri, which are also obliquely