Ascophrys rodor Campіllo et Deroux, 1974 : 1447

Dovgal, Igor & Mayén-Estrada, Rosaura, 2015, A taxonomic revision of order Pilisuctorida (Ciliophora, Apostomatia) with keys to the subordinate taxa, Zootaxa 4040 (5), pp. 543-558 : 553-554

Ascophrys rodor Campіllo et Deroux, 1974: 1447

( Fig. 2 E–F, 3H–T)

Ciliate parasite of shrimps cuticle. The phoront stage is attached to host epicuticle, surrounded by an exoskeleton, rounded, flattened with spherical macronucleus. The trophont is elongate and sac-like. Reproduction by non-linear synchronous palintomy with the formation of dozens of tomits. Tomite is flat, discoid, with U-shaped macronucleus, one central contractile vacuole, without cytostome, with adhesive organelle on one side and three parallel, oblique, short ciliary rows on the other side. The swarmer passes the metamorphosis from "zenithal" stage (with more developed locomotor ciliature) to "nadiral" stage (with better developed adhesive organelle) before settling on the surface of the host's body.

Measurements (in µm): Phoront body diameter 20–50, trophont body length up to 300 (after Campіllo and Deroux, 1974).

Type host: Palaemon serratus .

Type locality: Roscoff ( France).

Thus the association to a particular host (belonging to crustacean orders or families) has been considered the basis to determine the pilisuctorid species, and therefore the morphological and life cycle characteristics, useful for species identification, have not been discussed.

Jankowski (1972, 2007) noted that conidophryid trophonts practically are indistinguishable between species, unless the tomite kinetome is provided, and the knowledge of ciliary apparatus in apostomes (including Pilisuctorida) is still poorly as a diagnostic character.

We believe that for the identification of Pilisuctorida taxa the morphological criteria at different stages of ciliate development are necessary. However the representatives of various pilisuctorid genera are separated on the basis of some different stages of the life cycles, i.e. the life cycle of Ascophrys includes the trophont, phoront and tomite stages, for Conіdophrys the stages of trophont and swarmer, and finally for Askoella the only tomite-like trophont stage presented.

The representatives of genus Conіdophrys currently are definable at trophont stage. Thus, in our opinion, in this case the macronucleus outline and the mode of parasite attachment to host sectretory seta are most informative characters, while the kinetal pattern both in trophont and tomite stages generally are adjuvant characters.

The reproduction mode and kinetome structure in trophont and tomite stages will be useful for species identification of members of genus Ascophrys , and for species of the genus Askoella the analysis of the perioral rosette structure as well as the cell shape are necessary.

We summarize the morphological and connecting with reproduction characters are useful for taxa identification for preparing the keys below.

Figures

FIGURE 2. Ciliates of genera Askoella and Ascophrys described by different authors. A—ventral side of Askoella janssoni; B—dorsal side of A. janssoni (scale bar 10 µm); C—macronucleus morphology of A. janssoni; D— A. heliostoma; E—trophont of Ascophrys rodor: F—phoront of Ascophrys rodor (A – C—modified from Fenchel, 1965; D—modified from Jankowski 1967 b; E-F—modified from Deroux, Campillo and Bradbury, 1975).