Isostichopus badionotus

Populations of Isostichopus badionotus are primarily seen along the northern Pacific coast of South America and around the Galapagos Islands. Another region highly populated with this species is along the northeastern shores of Venezuela. (Jenkins and Mulliken, January 1999)

Isostichopus badionotus, like most echinoderms, prefer shallow water. The most suitable environments for these "bottom-feeding" animals are substrates set in the calm waters of channels and coves, shielded by high cover. (Gosner, 1978; Guzman and Guevara, 2002)

Isostichopus badionotus is shaped like a cucumber. It is radially symmetrical and lacks spines (typical of Echinodermata). The three-rowed sea cucumber also lacks any true appendages other than its tube feet. The animal is mostly solid in color, however, the side of its body that it uses to move along the sea floor is slightly lighter in pigment. Calcareous deposits are embedded in the epidermal layer of this animal. Having definite anterior and posterior ends, the sea cucumber has a large mouth surrounded by bushy tentacles with thick bases that divide into numerous tiny branches. A dark pigmented peristomial membrane surrounds a circular lip. (Bullough, 1950)

The three-rowed sea cucumber is a tubular organism, formed in specialized pelagic larval stages. In reproduction, sperm and eggs are released into the water & developing young undergo a complex metamorphisis. Organs and tissues are almost completely regenerative. (Bullough, 1950; Gosner, 1978)

Isostichopus badionotus have separate sexes and possess a reproductive system consisting of a single gonad and either an oviduct or a vas deferens. In temperate climates, eggs are laid in late winter and early spring. Sperm reach the eggs by way of the water. The fertilized eggs develop into free-swimming pelagic larvae.

A unique reproductive mechanism of Isostichopus badionotus is the ability to divide itself into two. (Conde, 1996)

There is no parental investment beyond spawning.

There is little known about the relationships between Isostichopus badionotus and other members of its phylum. They are essentially lone creatures that spend the majority of their lives feeding. The three-rowed sea cucumber seems to interact with other animals only in efforts to protect itself. (Gosner, 1978)

Echinoderms in general have a decentralized nervous system. Holothurians can right themselves when turned over, suggesting they have tactile and light receptors. In addition, some evidence suggest the buccal tentacles may be chemically sensitive. (Brusca and Brusca, 1990)

Three-rowed sea cucumbers are deposit-feeders, literally eating deposited material or sediments off of the ocean floor. Using its tentacles, the animal pushes large scoops of sediments into its mouth (Bullough, 1950).

Because sediments are typically low in concentration of nutrients, the sea cucumbers ingest enormous amounts of sediment per day to ensure proper nourishment. It is estimated that each Isostichopus badionotus ingests between 1 and 2.3 tons of sediment per year. Isostichopus badionotus is a selective feeder, especially in the presence of a competing species such as fish, or when a particular blend of sediment is high in organic material. Isostichopus badionotus prefers and is better adapted to the finest grain of sediment; however, the size and amount of sediments processed depends on the size of the individual (Conde, 1996). (Bullough, 1950; Conde, 1996)

Members of the class Holothuria will defend themselves by casting out most or part of their viscera through the cloacal opening, and in two to three weeks, regenerate the lost organs. (Gosner, 1978)

Three-rowed sea cucumbers ingesting and process food particles and discharge newly fixed and enriched matter that has a nutrient content greater than its surrounding environment. Once ingested, sediment particles stay inside the animal about 3 hours to ensure complete nitrogen-fixation.

This highly active process of filtering and enriching sediments is extremely important to marine conditions. Reworking modifies the physical and chemical stability of the marine environment by continually producing "new" ground and causing pulses in biodiversity. Through destroying both stratification of sediment layers and ridding its community of infestations, the Isostichopus badionotus plays a key role in structuring the micocommunities that exist. (Conde, 1996)

Harvested sea cucumbers are regarded as both a tonic and celebratory food in many East Asian cultures. (Jenkins and Mulliken, January 1999)

This species and the ecosystems in which it thrives are threatened both by contaminated substrates, where boats leave behind high concentration of metals, and by illegal fishing and export of the animals for eating purposes. Conservation strategies and limits on fishing are being considered. (Bruckner, et al., 2003)