Panagrolaimus peruensis

      Chromadorea
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         Rhabditia
          Panagrolaimidae

Originally described by Steiner and Christie (1939) as Neocephalobus peruensis. They recognized that the species was very close to Panagrolaimus and suggested that Neocphalobus should be considered a subgenus of Panagrolaimus. Goodey (1963) later transferred the species to the genus Panagrolaimus. The nematode was found with Diploscapter coronatus and Aphelenchoides hunti associated with diseased rhizomes of ginger (Zingiber sp.), shipped from Peru, at a Plant Quarantine station in San Francisco. Steiner also reported finding the nematode in shipments originating in Japan and China. The authors established that P. (Neocephalobus) peruensis is a bacterivore and A. hunti a fungivore and that neither was the causal agent of the disease of the rhizomes.

Morphology and Anatomy:


Female body stouter than that of male. Short cylindrical stoma. Long tapering corpus with no offset metacorpus. Valve in postcorpus. Female monovarial, prodelphic, ovary reflexed, offset spermatheca, with postvulval sac. Ovary reflexed beyond vulva and almost to level of rectum. Rapidly moving, very active nematodes.

Tail conical but asymmetrical, shorter on ventral side.	A. anterior; B. head lateral view; C. head ventral view; D. female gonad; E. male gonad; F. female tail, ventral view; G. vulva, ventral view; H. tail folded when nematode moves backwards; J. unicellular organism observed adhering to cuticle; K. two bacterial morphotypes in intestine. Drawings from Steiner and Christie, 1939.

	Male testis reflexed ventrally, spicules curved, gubernaculum present. No caudal alae.
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

Distribution:

Feeding:

Moves with constant turning of head, ingesting bacteria by alternate dilation and closing of esophageal canal and very rapid pumping action and movement of the valves of the terminal bulb of esophagus.

The nematode is observed to move foreard and backwards on an agar medium with the tail often folded anteriorly during backward motion. Steiner and Christie (1939) noted that if and bacteria survive passage through the intestine, the nematode will serve as an effective distribution agent due to the constant motion and activity.

Gadd and Loos (1943) reported similar feeding behavior for Panagrolaimus rigidus.

Biology and Ecology:

Life Cycle:

Ecosystem Functions and Services:

Management:

References:

Steiner, G. and Christie, J.R. 1939. Nematodes observed on diseased rhizomes of ginger from Peru. Proceedings Helm. Soc. Washington 6:26-29.

Gadd, C.H. and Loos, C.A. 1943. Observations on the life history of the nematode Panagrolaimus rigidus. Spolia Zeylanica 43:65-69.