Codium
setchellii
Epiphytes
Various
species of algae live on other plants, so-called epiphytes. Such epiphytes
are most common on crustose forms (though they do occur on erect algal
forms), and Codium setchellii is no exception. A variety of
species were observed growing on C. setchellii in the field.
Small
red algae were observed on both species of Codium in Carmel.
These red algae were fine and filamentous. When out of the water, they
appeared as nothing more than a course film on the alga, but when submerged,
these epiphytes branch out. The epiphytes were likely some species of
Ceramium, which commonly occurs on C. fragile. More
information on Ceramium can
be found here.
Fig. 1: Codium setchellii (left) and C.
fragile (right) observed in Carmel (CA) with small filamentous,
epiphytic red algae
Epiphytes
on Codium setchellii
The
literature shows a wide variety of algae living epiphytically on Codium
setchellii (Silva 2004). Some examples
include:
- Anthithamnion densum
- Ceramium gardneri
-
Ectocarpus commensalis
- Ectocarpus
siliculosus
- Erythrotrichea
carnea
- Feldmannia
simplex
- Griffithsia
pacifica
- Herposiphonia
plumula
- Polysiphonia
pacifica
- Porphyrostromium
boryanum
- Pterosiphonia dendroidea
Various,
unidentified red filamentous algae were observed on the Codium setchellii
crusts in the field at the Carmel site. Some fleshy red algae were also
observed growing epiphytically on the C. setchellii crusts iin
Carmel. Interestingly, the specimens observed at Point Pinos (Pacific
Grove, CA) did not have any visible epiphytes.

Figure 2: Close-up of C. setchellii with
epiphytes -
filamentous red alga (bottom), filamentous brown alga (right), and small
erect red alga (upper left)

Figure 3: Epiphytes of C. setchellii -
erect coralline algae and other erect red algae
Endophytes?
in Codium setchellii
Previous
work has found some algae living between the utricles of C. setchellii.
According to DeCew's Guide, Acrochaetium
rhizoideum
occurrs "endophytically" in C. setchellii. Upon sectioning
specimens of C. setchellii collected locally from the field,
various plants were found inside the alga's tissues. A fine red filament
was very common inside the tissue of one specimen; it remains unknown
if this filament was a red alga or a collection of cyanobacteria (unfortunately
the lack of powerful microscopes prevented a thorough analysis). There
is a small chance this filament was actually epiphytic (not endophytic)
and sectioning the alga mixed the sample, however, the intricate entanglement
of the red filaments among the utricles suggests they are indeed endophytes
if that satisfied the definition of an endophyte..

Figure.
4: Unidentified red filaments (either a red alga or cyanbacteria) among
the C. setchellii utricles
Animal
Communities in Codium setchellii
Not
only were numerous plant species found to be utilizing C. setchellii
as substrate for settlement and growth, but various animals were found
in close association with the alga. On a macroscopic level, various amphipods
and isopods were found underneath the crusts during collection. These
small crustaceans were not identified to species, but the alga undoubtedly
hosts a diverse assemblage of small crustaceans.
On
a microscopic scale, small animals were found living within the tissue
of C. setchellii specimens brought back to the lab. Several specimens
were observed hosting worms (likely nematode worms, but too small to fully
classify even to phylum). One specimen was also found with a microscopic
amphipod among the utricles. Yet another hosted a microscopic ostracod,
apparently still thriving within the alga's utricles.

Figure
5: Worms (probably nematodes) thriving within the utricles of C.
setchellii

Figure.
6: An ostracod found among utricles of C. setchellii, still
kicking its appendages and opening its hinged carapace
Choose
one of the following links to learn more about Codium setchellii:
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©
2005 Raúl Nava. Text and images freely available for personal,
educational use (please credit).
Please
e-mail me (rnava@stanfordalumni.org)
for any other use (including publication or commercial).
Last updated:
Mar. 20, 2005
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