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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Acyclus

Acyclus Leidy, 1882

ref. ID; 1663

Body long, with a long, annulated, tapering stalk and with or without a gelatinous case. Corona produced into a large dorsal lobe, and bordered by a thin, festooned membrane. Lives in Sinantherina colonies. Rare species. (ref. ID; 1663)
  1. Acyclus inquietus Leidy, 1882 (ref. ID; 1345, 1923, 2545, 3259)
  2. Acyclus trilopus (Lucks, 1911) (ref. ID; 1345)
    Syn; Hyalocephalus trilobus Lucks, 1911 (ref. ID; 1345)

Acyclus inquietus Leidy, 1882 (ref. ID; 1345, 1923, 2545, 3259)

Descriptions

This species is living attached in colonies of Sinantherina, the larvae of which it eats. Over 1 mm. (ref. ID; 1923)

Comments

Previously, this species has been reported as living exclusively in colonies of Sinantherina socialis where it stands among the members of the colony and eats the free-swimming young. In Boulder Lake, Vilas County, a specimen was seen in a colony of Sinantherina ariprepes. No young females Sinantherinae were present, but the Acyclus made violent efforts to grasp a male with the highly mobile dorsal lobe of the corona. Each time the male was saved by being knocked away from the Acyclus by the abrupt retractions of the active adult females. There can be no doubt that Acyclus is capable of eating young Sinantherinae for the characteristic malleoramate trophi have been found in its stomach. (ref. ID; 3259)