Ecology of Atlantic Shores: Intro

Introduction:

Interstitial invertebrates, simply put, are invertebrates that live in the water or air pockets between grains of sediment. The interstitial areas of intertidal zones are a very dynamic habitat, changing not only seasonally but also on a daily basis. Most taxonomic groups of invertebrates are represented in interstitial areas (Swedmark, 1963). Invertebrates found during my study were identified and placed into the following taxonomic groups; annelida, nematoda, crustacea, and turbellaria. More information on each group can be found below.

Annelida:

The phylum Annelida is made up of invertebrates commonly known as segmented worms and contains around 9,000 species, most of which are aquatic (http://www.earthlife.net/inverts/annelida.html). As the name implies annelids can

be identified by the many small segments that make up their body. Another important morphological feature of annelids are structures called chaetae. Chaetae are epidermal extarcellular structures, meaning they are extensions of the organisms' skin.

Crustacea:

Crustacea is a subphylum of the phylum Arthopoda comprising about 52,000

described species (wikipedia). Crustaceans are mostly marine and contain many commercially fished species such as crabs, lobsters and shrimp. They generally have many body segments and specialized appendages (Ruppert et al., 2004).

Nematoda:

Nematoda is one of the largest and most diverse phylum next to arthopoda. Nematodes can be free living in either aquatic or terrestrial environments, or can be parasitic. They are very simple organisms with no distinguishable body parts. They have a relatively well developed nervous system but no circulatory or respiratory organs (http://www.earthlife.net/inverts/
nematoda.html).

Turbellaria:

Tubellaria is a class of the phylum Platyhelminthes and consists of free-living flatworms. Most are marine organisms and are microscopic, although some are larger and can get up to 60cm long. The smaller species generally use cilia for locomotion while larger species use muscular movements of either all or part of the body (Ruppert et al., 2004).