Stichopus Fuscus

A Discussion of Stichopus Fuscus

This paper discusses the sea cucumber, or stichopus fuscus, including information about its habitat, feeding behavior, reproductive behavior and its use by humans. Currently, the stichopus fuscus is in danger of over-fishing, particularly in the Galapagos, one of its habitats. Yet research shows that the sea cucumber may have important uses by helping to repair injury done to human tissue. The stichopus fuscus is not salient danger ecologically speaking, but quite relevant to human interest needs.

This particular species, the stichopus fuscus, is found in the Galapagos. In the Galapagos, it is distributed throughout the archipelago, however it is most concentrated in the islands of Fernandina and Isabela. It can also be found in the eastern pacific, from Baja, California to Peru. Although mature stichopus fuscus can be found through out the year, between December and April is the greatest period of reproductive development. (Department of Marine Research and Conservation, Charles Darwin Research Station,

http://www.darwinfoundation.org/marine/FAQcuke.html, n.d.)

Sea cucumbers can reproduce both sexually and asexually, although sexual reproduction is the most common. During sexual reproduction, the egg and sperm are released in the water. By chemical attraction, the sperm is compelled toward the egg. There is one necessary condition for sexual reproduction: the high number of individual sea cucumbers. Because of this condition, if the distance between male and female sea cucumbers is too great, fertilization will not occur. After the egg has been fertilized, a larva develops and remains floating in the ocean. This continues for a number of months until a base is found. Once a base is found, the larva settles and transforms into a juvenile. Sea cucumbers are considered sexually mature when they reach the average length of 21 centimeters. (Department of Marine Research and Conservation, Charles Darwin Research Station,

http://www.darwinfoundation.org/marine/FAQcuke.html, n.d.)

Sea cucumbers have few predators. Its known predators are some sea stars, fishes and crustaceans. The eggs larvae and juveniles are a source of food for fish, crustaceans and mollusks. In response to these predators, sea cucumbers have evolved unique defense mechanisms, one of them being the release of toxic chemicals. They also have the ability to literally cut off either the entire organ or its parts. It also regenerates quickly. (Department of Marine Research and Conservation, Charles Darwin Research Station, http://www.darwinfoundation.org/marine/FAQcuke.html, n.d.)

Following is a description of the feeding behavior of sea cucumbers. Sea cucumbers grind up sediments and eat algae particles, sand and waste materials. Sea cucumbers consume and grind up sediment and organic matter, a process that allows for the penetration of oxygen. This process hinders the build up of decaying organic matter and aids the control of certain bacteria. In essence, they are “the recyclers of nutrients.” (Department of Marine Research and Conservation, Charles Darwin Research Station, http://www.darwinfoundation.org/marine/FAQcuke.html,n.d.)

The population of a particular sea cucumber has risen rapidly, scientists say. In the North Atlantic, the number of sea cucumber has dramatically increased. The population of sea cucumbers is measured by dredging the ocean floor. Prior to 1996, a sample revealed that only one or two sea cucumbers per hectare existed. In 1997, another sample indicated that there were thousands of sea cucumbers per hectare. This dramatic increase is explained by the influx of dead algae that the sea cucumber feeds on. Because there is more food, there is an increase in the number of sea cucumbers (Krieger, 2004, p. 2).

However, the fate of stichopus fuscus is not so bright.

Despite the efforts of the Ecuadorian government to protect the sea cucumber, exploitation still presents a great danger. In the Galapagos, the number of sea cucumbers is rapidly dwindling, despite the four-year ban imposed by the Ecuadorian government (Krieger, 2004, p. 2).

In 1998, the Special Law for Galapagos was signed "restricting exotic species immigration and commercial fisheries" (Kobler). Artisanal fishing, however is still allowed. Nevertheless, "4,401,657 sea cucumbers were exported, providing a gross income for GalÐ"ÐŽpagos over US $3.4 million” (Kobler, n.d.). Despite efforts at monitoring fishing, scientists believe that the sea cucumber needs time to recover or else suffer sever irrevocable exploitation (Kobler, n.d.).

The exploitation of the sea cucumber has led to a significant change in population density. There has been a significant decline in the number of sea cucumbers. Research shows that in some areas, reproductive viability is being threatened by