Draft:Exploring the Natural History of the Sea Pig (Scotoplanes)

The Natural History of Scotoplanes-the Sea Pig

Introduction The sea pig represents an amazingly deep-sea organism normally found in the unexplored, dark sea bottom of the ocean. It is in the family Elpidiidae and class Holothuroidea. Echinoderms belonging to this class habitually dwell in soft sediment on the bottom of the sea, normally within depths from 1,500 up to 5,000 meters. Their peculiar morphology and ecological roles create an object of important studies in marine biology.

Anatomy and Physiology Sea pigs can be described to have an elongated body shape, cylindrical of form, reaching up to 20 cm in length. Their bodies are soft, flexible, and are covered with thin, translucent skin that may take on pale pink to reddish coloration. Arguably, the most characteristic feature of the sea pig is that a set of short, stubby tube feet protruding from its body serves for locomotion across the soft substrate of the ocean floor. The tube feet bear small suckers, enabling the sea pig to anchor and manipulate sediment. In addition to their tube feet, the sea pigs have a peculiar respiratory structure that is the respiratory tree, adapted to extract oxygen from the water surrounding it. Deep-sea conditions are extremely variable in terms of oxygen saturation, a condition under which this adaptation becomes indispensable. Their digestive system is specialized, too, as detritivores, the animals feed on organic matter that falls to the bottom of the sea, gathering and ingesting this detritus with the tube feet. Their gut is very efficient, allowing the maximum amount of nutrition to be extracted from meager resources around the animal's immediate environment.

Ecological Role

The sea pig is very crucial to the deep-sea ecosystem. Being detritivores, they are able to show their importance in nutrient cycling and energy flow by processing organic matter that would otherwise be left lying on the bottom of the ocean floor. It is this feeding behavior that helps not only in decomposition organic materials but also aids in making nutrients available with other organisms, hence assuring a better marine environment. Also, social foraging has been found to be practiced by sea pigs, an unusual finding considering the poor and harsh environmental conditions in which they are found. In this respect, Smale and Touché (2005) reported that these animals often form aggregations of individuals probably in order to maximize foraging performance. While foraging together, sea pigs will be able to explore larger areas and can all enjoy the bumper gains when a given area exposes treasure with improved nutrient levels, something they all need for survival. Reproductive Strategies

Equally intriguing is the reproduction of the sea pig. While most marine organisms undergo complex larval phases, sea pigs undergo direct development; the embryos become miniaturized adults. This strategy is very advantageous under such nutrient-poor conditions as in the deep-sea and provides a good chance for the young sea pig to be better adapted for survival right from the beginning. This reproductive strategy might be one of the reasons for sea pig resilience, as they can occupy all the available ecological niches with more ease on the seabed. References: Thurston 1990.

These unique aspects of the biology of the sea pig come from a review of various scientific papers on the subject. Because of this, I decided to make my Wikipedia contribution about their social foraging behavior. This behavior not only puts into view the adaptiveness of the sea pig but also highlights its ecological importance in deep-sea habitats-a theme which is rarely represented in discussions about marine life.