Starfish, Simple, Slow, but Significant Marine Creatures
As you might be aware, the
4th Annual Reef
Festival is quickly approaching and will be held on Sunday, May
28th at Mar de Tumbo
Beach. In addition to boat trips to the reef, educational displays and
sporting events, the festival will feature the always popular marine life
touch tank. The touch tank gives children and adults alike the
opportunity to come into close contact with and learn more about common
marine species found in and around the coral reef environment. Each year,
employees of Amigos del Mar Dive Shop collect marine creatures from the
reef, such as sea cucumbers, anemones, sea hares, urchins and conch. They
place them in a water-filled tank for the afternoon, after which they are
returned to their natural habitat. All of these animals are interesting,
but there is little doubt that one of the most popular and easily
recognizable creatures found in the touch tank is the starfish (or sea
star).
It could be because they exist in a wide range of
beautiful colors, from blue to red to yellow; or because they are docile
and completely harmless to humans. Whatever the reason, the starfish is
easily one of the most popular and distinguishable of all marine
invertebrates (no backbone). There is no mistaking the body of this slow
moving creature, characterized with five to six arms that radially extend
from the center of the body, forming the shape of a star. These arms are
covered with tube feet and suckers, which assist the starfish in
crawling, feeding and clinging to surfaces. The strength of these suckers
is apparent if you have ever tried to pry a starfish from a rock. The
rigid body of the starfish is rough to the touch, covered with spines and
most species range in width from 0.4 inches to 26 inches.
There are approximately 1,500 species of starfish
found throughout the world, all of which are abundant at most ocean
depths. All starfish species use a mouth located on the underside of
their body to feed on ocean-bottom debris, as well as on mussels and
clams. Occasionally, when the starfish encounters larger prey, it will
force its stomach out through its mouth and digest the prey outside of
its body. Because of the variety of food the starfish consumes, it plays
a very important role in maintaining the diversity of the food
chain.
For the most part, however, starfish are
amazing inhabitants of the sea and bring enjoyment to those who come into
contact with them. Like all marine creatures, they play a role in the
marine ecosystem that cannot be underestimated. Be sure to check out the
starfish, as well as other fascinating marine animals at this year's Reef
Festival!
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Despite a slightly developed sense of touch, smell and
taste, the starfish is a relatively simple creature with a nervous system
that lacks a brain. To reproduce, most species release eggs and sperm
into the surrounding water, where fertilization takes place.
Interestingly, these invertebrates are also capable of regenerating body
parts from body fragments. For example, if a starfish were cut in half,
two whole starfish would grow from both halves. Generally, these
creatures avoid predation because they are known to be unappetizing and
lack nutrients, thus their populations are able to thrive. Occasionally,
in fact, starfish populations exceed normal levels, which can result in
the degradation of reef environments when these creatures overfeed on
coral.
Reef Brief is a weekly
column published in the San Pedro Sun
E-mail: - [email protected].
