A Female Chambersiellidae Specimen

Taxonomic Keys From Chromadorea, To Rhabditia To Chambersiellidae from Nemaplex

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Keys for Class Chromadorea to Subclass Chromadoria to Order Rhabditida to Family Chambersiellidae

1. Class Chromadorea
   1. Pore-like or slit-like amphid apertures, always labial.
   2. Amphid apertures on lips, often difficult to see; 
   3. No hypodermal glands; hypodermal cells are multinucleate; 
   4. No caudal glands; 
   5. Males with a single testis and with paired pre-anal supplements, sub ventral in 2 rows; 
   6. Three esophageal glands
   7. Deirids are present in some near the nerve ring.
   8. Phasmids present, generally posterior.
   9. There are no hypodermal glands, but hypodermal cells are multinucleated.
   10. Excretory system tubular.
   11. No caudal glands.
   12. Males generally have a single testis.
   13. Caudal alae are common.
   14. Male with paired preanal supplement glands in two sublateral rows.
   15. Sensory papillae are cephalic only, although they may be caudal papillae in males.
   16. The esophagus varies but has three esophageal glands.
   17. Almost exclusively terrestrial, rarely freshwater or marine.
   18.  Subclass Chromadoria
   19. Three-part esophagus (corpus, isthmus and postcorpus), valve in postcorpus; corpus and postcorpus in 12 cells
       1. Order Rhabditida
       2. Male with rays in delicate caudal alae
       3. Body Structure: They typically have a cylindrical, elongated body with a smooth cuticle. Adults are usually about 1 mm long, with females slightly longer than males.
       4. Lips and Sensilla: They possess six lips with sensilla arranged in two concentric circles around the mouth. Small amphid pores are located at the base of the lateral lips.
       5. Feeding Apparatus: The stoma (mouth opening) is tube-like with a prismatic cross-section. It includes a short cheilostom, a gymnostom, and a stegostom enveloped by pharyngeal tissue. The pharynx is muscular and tripartite, with a terminal bulb containing rhabditoid valves to crush bacteria.
       6. Reproductive Structures: Females have paired, opposed, reflexed ovaries, and the vulva is median. The male tail can vary in shape, often leptoderan or peloderan, with separate spicules.
       7. Ecological Roles: Rhabditida nematodes can be free-living, zooparasitic, or phytoparasitic. They play critical ecological roles as primary consumers, feeding on bacteria and organic matter in soil.
          1. Family Chambersiellidae
             1. Three-part esophagus (corpus, isthmus and postcorpus in 12 cells),
             2. Valve in postcorpus
             3. Corpus and postcorpus comprise 12 cells
             4. Cuticle finely striated with two lateral incisures.
             5. Lip region with six cephalic cirri (elaborate cephalic appendages) and 6-10 cephalic papillae.
             6. Anteriormost rhabdions of the stoma modified to form hooklike structures are distinct from the rest.
             7. The posterior part of the stoma forms a narrow vaselike glottid apparatus and is surrounded by tissue which is differentiated from that of the esophagus.
             8. Amphids opening behind the anterior broad chamber of the stoma;.
             9. Esophagus without a median bulb but with a valvulated terminal bulb.
             10. Monovarial.
             11. Vulva is slightly pre-equatorial to post-equatorial.
             12. Testis single.
             13. Male tail with several pairs of caudal papillae;
             14. Spicules paired and not joined; gubernaculum present;
             15. Rectal glands present;
             16. The tail of both sexes has a dorsally hooked terminus.

Consider (Species from World Register of Marine Species (WoRMS))

1. Chambersiella backeri Sanwal, 1957 accepted as Geraldius backeri (Sanwal, 1957) Sanwal, 1971
2. Chambersiella papillata (Rahm, 1928) Sanval, 1960 accepted as Diastolaimus papillatus Rahm, 1928
3. Chambersiella rodens Cobb, 1920
4. Cornilaimus furcillus Truskova &Eroshenko, 1977
5. Diastolaimus aculeatus (Daday, 1905) Andrássy, 1984
6. Diastolaimus croca (Massey, 1963) Andrássy, 1984
7. Diastolaimus damalis (Massey, 1966) Andrássy, 1984
8. Diastolaimus grossus (Truskova &Eroshenko, 1977) Andrássy, 1984
9. Diastolaimus papillatus Rahm, 1928
10. Fescia grossa Truskova &Eroshenko, 1977 accepted as Diastolaimus grossus (Truskova &Eroshenko, 1977) Andrássy, 1984
11. Geraldius backeri (Sanwal, 1957) Sanwal, 1971
12. Macrolaimus aculeatus (Daday, 1905) Thorne, 1937 accepted as Diastolaimus aculeatus (Daday, 1905) Andrássy, 1984
13. Macrolaimus arboreus Truskova &Eroshenko, 1977
14. Macrolaimus canadensis Sanwal, 1960
15. Macrolaimus citri Rahm, 1928 (uncertain >taxon inquirendum)
16. Macrolaimus crucis Maupas, 1900
17. Macrolaimus crucis sensu Fuchs, 1938 accepted as Macrolaimus canadensis Sanwal, 1960
18. Macrolaimus crucis sensu Meyl, 1960 accepted as Macrolaimus ruehmi Andrássy, 1960
19. Macrolaimus crucis sensu Rühm, 1956 accepted as Macrolaimus ruehmi Andrássy, 1960
20. Macrolaimus crucis gracilis Rahm, 1928 (uncertain >taxon inquirendum)
21. Macrolaimus crucis tenuis Rahm, 1928 (uncertain >taxon inquirendum)
22. Macrolaimus hamatus Thorne, 1937
23. Macrolaimus maipoensis (Rahm, 1932) Andrássy, 1978 accepted as Seleneella maipoensis Rahm, 1932
24. Macrolaimus natator Timm, 1960
25. Macrolaimus papillatus (Rahm, 1928) Goodey, 1951 accepted as Diastolaimus papillatus Rahm, 1928
26. Macrolaimus richteri Swart &Heyns, 1992
27. Macrolaimus ruehmi Andrássy, 1960
28. Macrolaimus somniorum Andrássy, 1984
29. Macrolaimus taurus Thorne, 1937
30. Santafea croca Massey, 1963 accepted as Diastolaimus croca (Massey, 1963) Andrássy, 1984
31. Santafea damalis Massey, 1966 accepted as Diastolaimus damalis (Massey, 1966) Andrássy, 1984
32. Seleneella gracilis (Rahm, 1929) Rahm, 1932 accepted as Macrolaimus crucis gracilis Rahm, 1928
33. Seleneella maipoensis Rahm, 1932 (uncertain >taxon inquirendum)