Novel alpine algae from New Zealand: Chlorophyta
Author
Novis, Phil M.
Allan Herbarium, Landcare Research, PO Box 40, Lincoln 7640, New Zealand; email: novisp @ landcareresearch. co. nz Department of Chemical and Process Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
Author
Visnovsky, Gabriel
text
Phytotaxa
2012
2012-01-01
39
1
30
http://biotaxa.org/Phytotaxa/article/view/phytotaxa.39.1.1
journal article
6144
10.11646/phytotaxa.39.1.1
836e6558-6d05-4ad0-8a82-d11b7c8f9b37
1179-3163
4894684
Schizochlamydella orbicularis
Novis & Visnovsky
,
sp. nov.
(
Figs 4D–E
)
Cellulae sphaericae vel subsphaericae,
3.1–6.1 µm
latae. Paries cellularis tenuis laevisque.
Chloroplastus viridis
, parietalis, lobatus, in cellulis valentibus incisuris 2–4 instructus. Pyrenoides nulla. Cellulae coloniales, mucilaginae maturae per matricem mucilaginis achromaticam instratosam uniformiter aequidistantes. Autosporis 2–4–8 per sporangium regenerans, eae per expansionem matricis gradatim separantes.
Type
:—
NEW ZEALAND
:
Westland
:
Mt Philistine
,
1400 m
, preserved cultured specimen from sample collected
30 November 2007
,
CHR610488
.
Cells colonial, spherical or near-spherical,
3.1–6.1 µm
wide. Cell wall thin and smooth. Chloroplast green, parietal, lobed, with 2–4 incisions in healthy cells. Pyrenoid absent (
Fig. 4E
). Colonies mucilaginous, mature cells spaced evenly through colourless, unlayered mucilage matrix (
Fig. 4A
). Reproduction by autospores, 2–4–8 per sporangium, gradually separating through expansion of mucilage matrix (
Fig. 4A
). Sequence data for both the
rbc
L and 18S rDNA genes suggested that the species formed a novel lineage in the
Trebouxiophyceae
, with no clear affinities (
Figs 8
,
9
).
Habitat:—
Alpine herbfield soil.
Distribution:—
New Zealand
.
FIGURE 4. A–C
.
Achoma brachiatum
(photographed from culture LCR-CG11).
A.
Light micrograph of vegetative cells showing variable shape, prominent pyrenoid (pyr), and incised parietal chloroplast (cp).
B
,
C
, Transmission electron micrographs of zoospore showing mitochondria (mito), chloroplast containing starch (st) and prominent pyrenoid (pyr), components of flagellar basal apparatus (fba), absence of cell wall, and branching pattern of thylakoids (tm) in the pyrenoid matrix.
D, E
Schizochlamydella orbicularis
(photographed from culture LCR-CG9).
D.
Light micrograph of mature cells evenly spaced in mucilage, and newly released autospores (arrow).
E.
Transmission electron micrograph of cell showing mitochondrion (mito), nucleus (nuc) cell wall (cw), and parietal chloroplast containing starch (st) but no pyrenoid. Scales: 10 µm in
D
(use for
A
and
D
), 1 µm in
B
,
C
, and
E
.
Etymology:—
“Spherical shaped”, referring to the cell.
Observations:—
The morphology of this species—mucilaginous colonies, lack of pyrenoids and zoospores—suggests an affinity with
Coccomyxa
, yet
S. orbicularis
is clearly a distant relative of species in the
Coccomyxa
clades. More discussion of these clades is given in remarks on
Pseudococcomyxa simplex
(below). The colonial mucilaginous habit lacking zoospores accords with the
Radiococcaceae
sensu
Ettl &
Gärtner (1995)
. Of the genera therein, the
New Zealand
strain most closely matches
Schizochlamydella
Korshikov (1953)
, with cells irregularly dispersed in homogeneous mucilage. Only one other species of
Schizochlamydella
lacks a pyrenoid, namely
S. minutissima
Broady (1982)
. However, this species is slightly smaller than our strain, with ellipsoidal juvenile cells. One species has previously received attention at the molecular level (
Wolf
et al.
2003
):
Schizochlamydella capsulata
(
Watanabe 1977
)
. This strain is distinguished from our material by containing one or more pyrenoids, and is placed in the
Oocystaceae
using 18S rDNA sequences (
Wolf
et al.
2003
), not closely related to
S. orbicularis
(
Fig. 8
). Given the paucity of characters available to classify these species, it is not surprising that morphology does not reflect phylogeny. Typification in the genus
Schizochlamydella
is problematic, however. The
type
species of the genus,
S. delicatula
(West)
Korshikov (1953)
was transferred to the chrysophycean genus
Phaeoschizochlamys
Lemmerman (1898)
by
Bourrelly (1957)
. However, this transfer was made without pigment or molecular analyses; we regard the choice of
Schizochlamys
for our material as prudent until the phylogenetic placement of the
type
species is clearly established.
Cultures:—
LCR-CG9.