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 This morphological-based classification system has been replaced by the Modern Phylogeny system, where taxonomy assignment is based on small subunit ribosomal DNA (SSU rDNA).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
Systematics
Subclasses and
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
s of Secernentea are:
Tree of Life Web Project
The Tree of Life Web Project is an Internet project providing information about the diversity and phylogeny of life on Earth.
This collaborative peer reviewed project began in 1995, and is written by biologists from around the world. The site ...
(ToL) (2002)
Nematoda
. Version of January 1, 2002. Retrieved November 2, 2008.
* Subclass
Rhabditia (paraphyletic?)
**
Rhabditida
**
Strongylida
* Subclass
Spiruria
**
Ascaridida[Nickle, W.R. (ed.), (1991). ''Manual of Agricultural Nematology''. New York, NY: Marcel Decker.]
**
Camallanida (sometimes included in Spirurida)
**
Drilonematida (sometimes included in Spirurida)
**
Oxyurida
Oxyurida is an order of nematode worms of the class Secernentea. It consists of four families, one of which contains the human pinworm (''Enterobius vermicularis'').
Species
Notable species include:
* '' Enterobius vermicularis'', the huma ...
(=
Rhabdiasida)
**
Rhigonematida (formerly in Tylenchia)
**
Spirurida
* Subclass
Diplogasteria
Diplogasterida was an order of nematodes. It was sometimes placed in a monotypic subclass Diplogasteria, but molecular phylogenetic evidence has shown it to be embedded in the family Rhabditidae (formerly Rhabditina). The confusion of having ...
(may belong in Rhabditia)
**
Diplogasterida
* Subclass
Tylenchia (may belong in Rhabditia)
**
Aphelenchida
Aphelenchida is a moderately large order of nematodes. Aphelenchida have a stylet for feeding and a very prominent median bulb in the oesophagus. They are cosmopolitan. Some are associated with insects, and may be ectoparasites or endoparasit ...
**
Tylenchida
Tylenchida is an order of nematodes.
List of families
* Superfamily Criconematoidea
** Family Criconematidae
** Family Tylenchulidae
* Superfamily Tylenchoidea
** Family Anguinidae
** Family Belonolaimidae
** Family Dolichodori ...
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.
References
Protostome classes
Obsolete animal taxa
{{Secernentea-stub