Usconophrys
Usconophrys Jankowski, 1985 (ref. ID; 4335)
[ref. ID; 4335]
Emended description; Lorica hemispheroidal, with thick walls; aperture without means of closure, located at anterior end of dorsal surface of lorica, surrounded by rim that projects slightly from dorsal surface of lorica. Body and lorica distorted laterally and flattened, with superficially bilateral symmetry. Solitary. Stalk absent; individuals attached to host by flat, ventral surface of lorica. Telotrochs and microconjugants produced on right side of parent; microconjugants attach to right side of macroconjugant. (ref. ID; 4335)
Type species; Lagenophrys aperta Plate 1889 by designation (Jankowski, 1985) (ref. ID; 4335)
- Usconophrys aperta (Plate, 1889) Clamp, 1991 (ref. ID; 4335 redescribed paper)
Syn; Lagenophrys aperta Plate, 1889 (ref. ID; 4335); Usconophrys dauricus Jankowski, 1986 (ref. ID; 4335)
- Usconophrys dauricus Jankowski, 1986
See; Usconophrys aperta (ref. ID; 4335)
- Usconophrys rotunda Precht, 1935 (ref. ID; 4335)
Syn; Lagenophrys rotunda Precht, 1935 (ref. ID; 4335)
Usconophrys aperta (Plate, 1889) Clamp, 1991 (ref. ID; 4335 redescribed paper)
Synonym
Lagenophrys aperta Plate, 1889 (ref. ID; 4335); Usconophrys dauricus Jankowski, 1986 (ref. ID; 4335)
Emended description
Lorica subcircular or suboval in dorsal view, varying widely in proportion of length to width. Lorica rim either unthickened of slightly to moderately thickened. Lorica aperture as described for genus. Infraciliature of peniculi as follows: Rows 1 and 2 of P1 equal in length, ending at cytostome; row 3 of P1 moderately shorter than other rows of P1. Rows of P2 approximately equal in length, ending at adstomal curvature of P1. Abstomal end of row 1 of P2 separated from abstomal ends of rows 1 and 2 of P2, curving sharply away from them. P3 has two rows that begin far above adstomal end of P2; row 1 of P3 begins slightly above row 2 of P3. Both rows of P3 extend to point approximately midway between adstomal curvature of P1 and adstomal end of row 3 of P1. Rows of P3 are closely parallel for entire length. Macronucleus compact, spheroid or ovoid, and located in left half of body. Micronucleus ovoid or spheroidal, located near macronucleus. (ref. ID; 4335)
Remarks
Usconophrys aperta was included in the genus Lagenophrys for nearly 100 years even though Plate's (1889) and von Ubisch's (1913) papers clearly depicted the features of its structure and reproduction that differentiate it from any species of Lagenophrys. Living individuals of U. aperta do not retreat far from the lorica aperture when contracted, making the lack of association between the peristomial lip and the edge of the aperture difficult to perceive when the animal is viewed from above. While this is a possible explanation for the long inclusion of U. aperta in Lagenophrys, the freedom of its peristomial lip from the edge of the lorica aperture is easily seen if the peristome is observed directly through the aperture in frontal view. In addition, U. aperta contracts more forcefully than usual when fixed, pulling so far away from the lorica aperture that the lack of a physical connection between its peristomial lip and lorica aperture is obvious. Usconophrys aperta has been found only on freshwater isopods of the genera Asellus (Europe) and Caecidotea (North America). In Europe, U. aperta is known to occur in Germany and France. In North America, I found it only on hosts collected in North and South Carolina. It was not seen on the many samples of Caecidotea from other areas of the United States and Canada that were examined. Plate (1889) and Nenninger (1948) record U. aperta from only the posterior surface of the host's gills. This specificity of location on the host was true for most samples of U. aperta examined although a few individuals were also present on the anterior surface of gills in some samples. Dimensions and proportions of the lorica varied greatly both between and within populations of U. aperta. Almost no differences existed between widely separated populations in regard to other attributes. For this reason, I considered all forms of U. aperta I examined, despite differences in the shape of their loricae, to be conspecific. Usconophrys dauricus was described as a separate species solely on the basis of its relatively elongate lorica (Jankowski 1986), but it resembles U. aperta otherwise, especially in the shape and position of the macronucleus. Both species also occur on asellid isopods. The lorica of U. dauricus is only slightly longer in relation to its width (Jankowski 1986) than the more elongate individuals seen in samples of U. aperta from France and North Carolina. In my opinion, this is not enough to make the two species qualitatively different in light of the variation in proportions I observed; therefore, I have made U. dauricus a synonym of U. aperta. In U. aperta, microconjugants as well as telotrochs are formed on the right side of the parent. Microconjugants arise near the posterior end of the right side during the differentiation division that precedes conjugation and also attach there during conjugation. This is completely opposite to the location of microconjugant formation and attachment in lagenophryids, which occurs at the anterior end of the left side. This reinforces the conclusion that lateral distortion of the body has occurred in exactly opposite directions in Usconophrys and lagenophryids. Metamorphosing individuals in the act of secreting their lorica were seen frequently in samples U. aperta. Such individuals contained a large, central vacuole that expanded the body to the dimensions of the lorica, holding its shape while it hardened. This method of fashioning the lorica shape is essentially identical to that described for species of Lagenophrys (Debaisieux 1959; Willis 1942), although its presence in both genera is surely an example of convergence. Metamorphosing individuals of U. aperta were conspicuously different from metamorphosing individuals of Lagenophrys in their lack of the expansions of the peristomial lip and thickened peristomial sphincter characteristic of the latter (Clamp 1987). (ref. ID; 4335)
Type locality and host
GERMANY, Hessen, Marburg; on Asellus aquaticus (L.), upper side (posterior surface?) of gills (Plate 1889). Plate did not specify where he collected the isopods on which he found U. aperta; therefore, it is assumed that they were obtained near his residence in the vicinity of Marburg. (ref. ID; 4335)
Type material
Two slides (hematoxylin preparations) of material from France will be designated neosyntypes and deposited. (ref. ID; 4335)
Synonym
Lagenophrys rotunda Precht, 1935 (ref. ID; 4335)
Descriptions
Usconophrys rotunda n. comb., a commensal of ostracods (Precht 1935), appears to resemble U. aperta except for the shape of its macronucleus, which is elongate, cylindroid, and horseshoe-shaped rather than compact. Also, the macronucleus is centrally located in U. rotunda instead of being confined to the left half. Usconophrys rotunda is included in the genus mainly on the strength of Precht's (1935) single figure that clearly shows the peristome structure and lorica aperture. Unfortunately, his figure of the species is a lateral view that omits much of the body's structure. (ref. ID; 4335)