KOROR STATE GOVERNMENT MARINE TOUR GUIDE ... - C3

Like humans, a given medusa is either female or male. Female medusae produce eggs
and male medusae sperm. The fertilization of an egg by a sperm produces a small,
round, swimming organism called a larva. Upon maturation, which takes several days,
the larva locates a suitable habitat on the side of the lake, usually a rock, dead leaf or
piece of wood, stops swimming and settles down on it. The larva then undergoes a
radical physical change, transforming itself from a round, swimming ball of cells into a
sedentary polyp with tentacle-surrounded mouth and supportive stalk. The polyp then
lives its entire life attached to that object, using its tentacles to capture small animals
from the environment around it.
Polyps are reproductively more flexible than medusae (which can only give rise to polyps
via sperm and eggs and the motile larval stage) in that they can produce both new
polyps and new medusae. Individual polyps give rise to new polyps by producing a small
outgrowth from their body that detaches, swims away, settles on the bottom and quickly
grows into a replicate of its parent polyp, complete with all the reproductive abilities of its
parent.
Alternatively, under certain conditions, a polyp will produce a new medusa by physically
transforming its mouth and tentacle end into a very small medusa (about 2-3mm
diameter), which pops off, swims away, and grows into a mature sexually reproductive
medusa. The remaining polyp then regrows a mouth and tentacles and lives on with the
potential to produce additional medusae and polyps.
Golden jellyfish polyps, note golden color due to mutualistic algae. Lower right hand
corner: Polyp producing a new medusa.
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