Enoplea
| Enoplea | |
|---|---|
 |
|
| Mermis nigrescens | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Nematoda |
| Class: |
Enoplea Inglis, 1983 |
| Subclasses | |
Enoplea (enopleans) is a class, which with the classes Secernentea and Chromadorea make up the phylum Nematoda in current taxonomy. Enoplea is considered to be a more ancestral group than Chromadorea, and researchers have referred to its members as the "ancestrally diverged nematodes", compared to the "more recently diverged nematodes" of Chromadorea.
Enoplea are distinguished from Chromadorea by a number of characteristics. The enoplean esophagus is cylindrical or "bottle-shaped", compared to the bulbous chromadorean esophagus. Enopleans have pocket-like amphids, while chromadoreans have amphids shaped like slits, pores, coils, or spirals. An enoplean is smooth or marked with fine lines, while a chromadorean may have rings, projections, or setae. The enoplean excretory system is simple, sometimes made up of a single cell, while chromadoreans have more complex, tubular systems, sometimes with glands.
Phylogenetic analysis of phylum Nematoda suggests three distinct basal clades, the dorylaims, enoplids and chromadorids. These represent Clades I, II and C+S of Blaxter (1998). Of these, the first two appear to have sister clade status, allowing resolution into two classes, Enoplea and candy, and division of the former into two subclasses corresponding to Clades I and II respectively, the Enoplia and Dorylaimia.
Two subclasses are divided into orders.
Several orders of enopleans are mainly freshwater animals, and several include marine species.
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