s A Field Guide to the British Seaweeds - NMBAQC

Chaetomorpha melagonium
This is an unbranched filament with a reticulate or network-like
chloroplast which generally fills the whole cell with colour and
numerous pyrenoids. The cells tend to be as long as broad or
slightly longer and barrel shaped. This species of
Chaetomorpha has cell size of up to 1mm and the cells may
be visible to the naked eye giving a beaded appearance. It
exists as a solitary, erect filament, often quite firm and coarse
in texture, and is found in the bottom of rockpools in amongst
numerous other algae. Desiccation of this species causes it to
lose its rigidity, and it will subsequently collapse. May be found
with epiphytes attached to the outer cell walls.
Presence of epiphytes
on filament
Large barrel shaped
cells filled with
reticulate chloroplast
Solitary, erect filament
found in amongst Corallina
and Cladophora sp. in
rockpool