Glossary - Freshwater Algae: Identification, Enumeration and Use as Bioindicators - page 254

Centrales Diatoms that are radially symmetrical
and usually circular in outline from the valve view -
Centric Diatoms

Cyst A thick-walled resting spore whose walls may
be impregnated with silica

Cytoplasm All of the protoplasmic content of the
cell excluding the nucleus

Chaetae Hairorbristle-likegrowthsofthecellwall

Daughter cells Cells formed by division of the
mother cell

Chloroplast An organelle within the cell con-
cerned with photosynthesis and containing the pho-
tosynthetic pigments. Often green in colour but can
be golden to brown (or other colour) depending upon
the combination of pigments present.

Daughter colony A new colony arising within a
mother cell or mother colony

Dendroid Tree-like, branching like a tree or bush.
Used to describe the colony shape in Dinobryon ,
which is not truly filamentous

Cingulum Part of the girdle region of a diatom
associated with one valve

Clathrate With obvious spaces between the cells DIC Differential interference contrast (light

microscopy)

Clavate Club-shaped

Dichotomous Branching or dividing to form two
equal-sized branches

Coccoid Cells that are rounded or spherical

Coenobium A colony of cells whose number is
fairly constant (often a multiple of four), the number
being determined early on in its development and no
further increase takes place until a new generation
develops. The cells are arranged in a specific way.

Dorsal The upper or more convex surface of a cell
(as opposed to lower or ventral), e.g. in the diatom
Cymbella

Dorsiventral A cell with two margins showing dif-
ferent curvature

Coenocytic Having multinucleate cells or struc-
tures, e.g. in Vaucheria which is not divided into
cells

Dorsiventral flattening Flattened in cross section
in a cell, similar to laterally flattened or flattened in
side view

Colony A group of cells joined together more
or less permanently, or enclosed within the same
mucilage or sheath

Ellipsoidal A figure with curved margins but elon-
gate ends which are sharply rounded

Endospore Non-motilesporeproducedinanindef-
inite number from a parent cell, e.g. in Chamae-
siphon

Contractile vacuole A small, usually spherical,
body which regularly fills and then contracts, associ-
ated with osmoregulation. Often found in flagellates

Epicingulum Girdle sections produced from the
parent cell in diatoms

Costae An elongate thickening (rib) on a diatom
valve (singular Costa)

Epicone The upper or anterior part of a dinoflagel-
late cell Crenulate Gently wavy

Epilithic Living on rock surfaces
Epipelic Free living on sediments

Crescent-shaped Shaped like the arc of a circle
and tapering towards the ends

Cruciform Having four arms and shaped like
a cross

Epiphytic Living on a plant surface

Episammic Living on sand grains

Crustose Crust-like. Composed of flat tiers of cells

Epitheca The part of the cell wall of a dinoflag-
ellate above the transverse furrow or in diatoms the Cuneate Wedge-shaped