''Rhodochorton'' is a genus of filamentous

red alga Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...

adapted to low light levels. It may form tufts or a thin purple "turf" up to 5 millimetres high. The filaments branch infrequently, usually at the tips.

Morphology

In most species of ''Rhodochorton'', the

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

does not persist in the mature plant; instead, a basal web of filaments acts as a holdfast. Indeed, all ''Rhodochorton'' species have distinct basal threads, usually forming a disc, and upright threads, which are typically thinner. Lateral branches usually occur at or near the top of the patent cell, and branching is concentrated towards the tips of threads.

Ecology

The organism may encrust bare rock surfaces, or be

epiphytic An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...

upon

frondose Frondosity (from Latin ''frondōsus'' meaning 'leafy') is the property of an organism that normally flourishes with fronds or leaf-like structures. Many frondose organisms are thalloid and lack the organization of tissues into organs, with the ...

algae - particularly ''

Laminaria hyperborea ''Laminaria hyperborea'' is a species of large brown alga, a kelp in the family Laminariaceae, also known by the common names of tangle and cuvie. It is found in the sublittoral zone of the northern Atlantic Ocean. A variety, ''Laminaria hyper ...

''. It typically grows in the shadow of these larger algae, in the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

, and its adaption to low light levels means it is also common in caves. It reproduces in winter using

tetrasporangia Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...

and don't bear any monosporangia. ''Rhodochorton'' is typically marine, but ''R. investiens'' dwells in fresh water.

Sexual reproduction Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote th ...

has never been observed. It suffers grazing pressure from gastropods and amphipods, but amazingly fragments of the algae are able to pass through the grazers' digestive tracts alive - grazing may actually form a mode of dispersal for the organism.

Life history

Rhodochorton investiens ''Rhodochorton'' is a genus of filamentous red alga adapted to low light levels. It may form tufts or a thin purple "turf" up to 5 millimetres high. The filaments branch infrequently, usually at the tips. Morphology In most species of ''Rhodoc ...

'' displays a relatively simple life cycle for a red alga. In the

Carposporophyte {{Short pages monitor