utricles within Codium produce the gametes. The gametangia
appear as separate branches from the other utricles comprising the alga's
internal structure. These transparent structures have dark, globular
Figure 1: Schematic of the utricles of C.
reproductive gametangia (After Scagel 1967)
(After Scagel 1967 and personal observations)
of the specimens collected during winter 2005 were obviously
reproductive. Various individuals were observed with enlarged utricles,
that do appear to be gametangia, but are likely not fully developed.
Records from Gardner (1919) show that C.
setchellii is usually reproductive in the winter months, thus
the presence of reproductive individuals would be expected.
Figure 2: Suspected gametangia of C. setchellii
reproduction of C. setchellii has been inferred from the published
data for the congeneric C. fragile, as the reproductive cycle
of C. setchellii has yet to be fully investigated. The gametangia
form separate from the utricles of the alga. These release anisogametes,
typically with larger female gametes (anisogamy). Both male and female
gametes are biflagellated, with symmetrical flagella. The tips of the
gametangia become ripe with gametes seasonally and eject bursts of the
(1919) noted fertile C. setchellii females in the winter months.
life cycle of Codium setchellii is presently uninvestigated
in the scientific literature. Most believe the life history is similar
to that of the congeneric C. fragile (Bold
and Wynne 1978). This species has a diplontic life cycle, meaning
the alga is always diploid (containing two copies of the genetic
information, much like humans). The diploid alga forms reproductive
gametangia, where the gametes develop. These burst seasonally and
release gametes, which fuse and the zygotes settle onto a substrate
and develop into a new diploid alga. The alga is presumed to be dioecious,
having separate male and female individuals. This life history is
summarized below in figure 3.
3: Presumed diplontic life history for Codium setchellii
one of the following links to learn more about Codium setchellii:
2005 Raúl Nava.
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