Panagrellus		Contents		Rev 09/18/2020
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Panagrellus menu				Ecosystem Functions and Services
		Distribution		Management
Return to Panagrolaimidae menu		Feeding		References
Go to Nemaplex Main Menu				Go to Dictionary of Terminology

Classification:

 Chromadorea
        Rhabditida
         Rhabditia
          Panagrolaimidae

Panagrolaiminae

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Morphology and Anatomy:

The main morphological charachters useful for separating species of Panagrellus are the shape of the spicules and, sometimes, the form of the vulva (Hechler, 1971).

General characteristics of the genus:

• Cuticle with extremely shallow transverse stria
• Lateral fields with four deeper longitudinal striations at midbody
•  Head continuous with or only slightly offset from body and with six slightly separated lips.
• Cheilostom  hexagonal in cross section, lining not sclerotized. Prostom partially surrounded with esophageal collar, lining sclerotized, thicker posteriorly.
• Stoma triangular behind prostom, dorsal wall slightly protruding with a small central wart.
• Three narrow dorsal teeth just behind wart, two pairs subventral teeth posterior to dorsal teeth.
• Procorpus 55 to 65% of esophageal length, nerve ring just anterior to basal bulb,
• Excretory pore between nerve ring and anterior limits of isthmus
•  Vulva and anus in females transverse slits, slightly curved anteriorly. Vagina shape varying between species.
• Female tails elongate-conical .
• Male tail tapering to slightly offset flagellum.
•  Posterior end of males with seven pairs of papillae: (i) subventral just anterior to spicule manubrium; (ii) subventral adanal; (iii) lateral adanal; (iv, v) two closely approximated subventral pairs midway between anus and beginning of tail flagellum; (vi) subdorsal, position variable within species, behind anus; (vii) subdorsal just anterior to tail flagellum. the the position of each pair of papillae may vary considerably within a species,.
•  Phasmids obscure, located at 45 to 50%, rarely as far forward as 35%, of tail length in females; opposite posterior subdorsal papillae in males.
• Spicules differing among species. Detailed descriptions in Hechler (1971).

Ref: Hechler, 1971

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Distribution:

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Feeding:

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Biology and Ecology:

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Life Cycle:

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Ecosystem Functions and Services:

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Management:

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References:

Ferris, H. 2009. The beer mat nematode: A study of the connectedness of scientific discovery. Journal of Nematode Morphology and Systematics 12:19-25.

Hechler, H.C. 1971. Taxonomic Notes on Four Species of Panagrellus Thorne (Nematoda: Cephalobidae). 3:227-237.

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Copyright © 1999 by Howard Ferris.
Revised: September 18, 2020 .