Morphological Comparison of Diophrys scutum (Dujardin, 1841) and Diophrys peloetes n. sp. (Hypotrichida, Ciliophora)

SYNOPSIS. Diophrys scutum , collected from four locations on the New Hampshire coast, ranged from 89–195 7mu; in length, 50–105 μ in width, and 68–88 μ in buccal cavity length. The end of the adoral zone of membranelles (AZM) extends 37–59 μ (average = 45.6 μ) posteriorly in a groove on the right side of the body. Dorsally are five rows of stiff cilia. The silverline system (Chatton-Llvoff technique) appears as a fine meshwork, entirely different from that found in Euplotes or Uronychia . There are two elongate macronuclei (Feulgen reaction) and several micronuclei. Diophrys peloetes n. sp., collected from one location in Alligator Harbor. Florida, ranged from 95–134 μ in length, 62–84 μ in width. and 60–80 μ in buccal cavity length. The terminal portion of the AZM extends posteriorly in a groove 30–44 7mu; (average = 36.8 μ) on the right side of the body. Dorsally are eight rows of stiff cilia. The details of the silverline system are similar to those of D. scutum .
There is insufficient difference in ranges of body length, width. and buccal cavity length to use these characters in separating the two species. However, a statistical analysis shows that the length of the portion of the AZM on the right side of the body in D. scutum is significantly different (longer) from that of D. peloetes. Furthermore, these two species differ not only in number of dorsal ciliary rows, but also in the number of cilia per row. The degree of difference in these two species is similar to that between closely related species in other hypotrich genera, and also to that between some varieties of Paramecium aurelia.