Secernentea was a class of nematodes in the Classical Phylogeny System (Chitwood, 1958) and is no longer in use.[1][2] This morphological-based classification system has been replaced by the Modern Phylogeny system, where taxonomy assignment is based on small subunit ribosomal DNA (SSU rDNA).[3][4]
Characteristics of Secernentea are:
Subclasses and orders of Secernentea are:[5]
Some families traditionally considered to be Rhabditida seem to be closer to the Tylenchida. If the Tylenchia are to be maintained as separate, they probably will be included therein.
{{cite journal}}: Cite journal requires |journal= (help) Secernentea was a class of nematodes in the Classical Phylogeny System (Chitwood, 1958) and is no longer in use. This morphological-based classification system has been replaced by the Modern Phylogeny system, where taxonomy assignment is based on small subunit ribosomal DNA (SSU rDNA).
Characteristics of Secernentea are:
Amphid apertures are pore/slit-like Derids are present in some; located near nerve ring Phasmids are present; posterior Excretory system is tubular Cuticle is striated in two to four layers; lateral field is present Three esophageal glands; esophageal structure varies Males generally have one testis Caudal alae are common Sensory papillae are cephalic only; may be caudal papillae in males Mostly terrestrial Rarely found in fresh or marine water