Aquatic Parasite Observatory

Gyrinicola batrachiensis (Walton, 1929)

    • Species Name: Gyrinicola batrachiensis (Walton, 1929)
    • Synonyms: None
    • Taxonomy: (Walton, 1929) Animalia, Nematoda, Secernentea, Ascaridida, Cosmocercidae, Gyrinicola batrachiensis
    • Life Cycle: “Gyrinicola batrachiensis has a direct life cycle, and tadpoles acquire initial infections by ingesting thick-shelled eggs that are distributed on the pond bottom. Female worms have a complex reproductive anatomy. One uterine horn produces thick-shelled unembryonated eggs used as transmission agents from tadpole to tadpole, whereas the second uterine horn produces thin-shelled eggs with juveniles used for autoinfection. All thin-shelled autoinfective eggs cannot survive outside of the tadpole host and die within an hour in pond water. Importantly, the development of the genital tract producing thin-shelled autoinfective eggs varies according to the amphibian species and its larval developmental time” (Rhoden and Bolek, 2011).
    • Description:
      1. The body is stout and short, tapering abruptly at the posterior end to a long naked spike-like tail. The anterior end shows distinct annulations which become indistinct caudad. Lateral flanges are indistinct or absent. The mouth is surrounded by three indistinct lips. No buccal cavity or vestibule is present. The esophagus shows a prominent posterior bulb separated by a distinct constriction. The excretory pore, contrary to the conditions in the other species of the genus, is opposite the esophageal bulb instead of being more posteriorly placed. The vulva is much farther from the excretory pore than common for the genus, but still is characteristically in the anterior half of the body. A distinct vagina gives rise to the coiled uteri which occupy most of the body space of the mature adult. The eggs are a much flattened ovoid and show distinct terminal plugs. This species is oviparous, the eggs showing no signs of segmentation when oviposited. The general measurements are as follows: Length, 4.2 mm.; width at vulva, 0.365 mm.; length of esophagus, excluding bulb, is 0.56 mm.; diameter of bulb is 0.125 by 0.15 mm.; nerve-ring is 0.165 mm. from the lips; excretory pore is 0.61 mm. from the lips; vulva-head distance is 1.8 mm.; anus-tail distance (including spike) is 0.9 mm.; spike is 0.76 mm. in length; the eggs measure 35 by 100kt and are surrounded by a double membrane, the inner one of which shows the terminal plugs.
    • Sources: Walton, A.C. 1929. Studies of some nematodes of North American frogs. Journal of Parasitology, Vol. 15, p. 227-240.
      Rhoden, H.R. and Bolek, M.G. 2011. Distribution and Reproductive Strategies of Gyrinicola batrachiensis (Oxyuroidea: Pharyngodonidae) in Larvae of Eight Species of Amphibians from Nebraska. Journal of Parasitology, Vol. 97, Issue 4, p. 629-635.
    • APO Parasite Records: (by Life Cycle)
  • University of Colorado Boulder