Chlorophyta-6

Trichocine Group-1

This group includes the Ulotrichales & Ulvales as well as the Chaetophorales & Coleochaetales. We will focus on these Classes because of their general importance and their relevance to Hawai'i.

Other related groups are the Oedogniales & Zygnematales.

These include multicellular organisms that are Filamentous or Parenchymatous.

Only the reproductive cells are Motile.

Ulothrix is a filamentous organism with diffuse transverse cell divisions. This type of growth is called Uniseriate and produces an unbranched filament. It can grow in Marine & Freshwater environments.

The Chloroplasts of many species tend to have a similar open, strap-like shape as seen with Ulothrix.

When cells of a Uniseriate filament divide longitudinally they can produce a Biseriate (two series) filament.

Further longitudinal divisions in one plane can "fan out" to produce a Multiseriate Sheet like some Enteromorpha & Monostroma species. These are only one cell thick. The red alga Porphyra superficially resembles Monostroma.

Ulva (Sea Lettuce) is very similar except that it is two cells thick.

Note the flattened areas near the tips of the thalli above.	Enteromorpha can form narrow (left) to wide sheets (above) which are only one cell thick.
Enteromorpha can grow in Marine and Estuarine habitats. It can proliferate in warm, nutrient-rich environments and is a major Biofouling pest.	Monostroma is also one cell thick, like Enteromorpha.


Ulva is very similar to Enteromorpha but it is two cells thick.
Ulva californica	Ulva lobata

The species above show a progression of Growth Forms which led from a Uniseriate Filament (Ulothrix) to a Multiseriate, Multistratose form (Ulva).

Link to Sexual Reproduction of Ulva