The Labyrinthulomycetes (
ICBN
The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...
) or Labyrinthulea (
ICZN) are a
class of
protists that produce a network of
filaments or tubes,
which serve as tracks for the cells to glide along and absorb
nutrients
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excr ...
for them. The two main groups are the
labyrinthulids (or slime nets) and
thraustochytrids. They are mostly
marine, commonly found as
parasite
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...
s on
alga
Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from u ...
e and
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the ...
es or as decomposers on dead plant material. They also include some parasites of marine invertebrates.
Characteristics
Although they are outside the cells, the filaments of Labyrinthulomycetes are surrounded by a
membrane
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. ...
. They are formed and connected with the cytoplasm by a unique organelle called a sagenogen or bothrosome. The cells are