Pyxicola, Kent, 1882

Lu, Borong, Li, Lifang, Hu, Xiaozhong, Ji, Daode, Al-Rasheid, Khaled A S & Song, Weibo, 2019, Novel contributions to the peritrich family Vaginicolidae (Protista: Ciliophora), with morphological and phylogenetic analyses of poorly known species of Pyxicola, Cothurnia and Vaginicola, Zoological Journal of the Linnean Society 187 (1), pp. 1-30 : 4

GENUS PYXICOLA KENT, 1882

No species of Pyxicola have previously been investigated successfully using silver staining methods ( Trueba, 1978). This genus is characterized by the operculum attached to the zooid just below the peristomial lip. The lorica is inhabited by a single zooid that is attached to a non-contractile stalk. The anterior portion of the lorica is usually oblique and neck-like.

PYXICOLA PUSILLA ( WRZEŚNIOWSKI, 1866) KENT, 1882

( FIGS 2A–P , 3A–U; TABLES 1–3)

Since its original description, Cothurnia pusilla were reported repeatedly ( Wrześniowski, 1866, 1867, 1870). However, the ciliature of P. pusilla has never been revealed. An improved diagnosis based on previous reports and new data is supplied.

Figures

Figure 2. Pyxicola pusilla in vivo (A–N) and after protargol staining (O, P). A–D, lateral views of different individuals, showing the varieties of body shape, lorica transparency and stalk length. E, a contracted individual inside the lorica. F, longitudinally oriented macronucleus.G–J, varieties of lorica shape. K, lateral view of operculum.L, apical view of operculum. M, details of lorica base, mesostyle and endostyle. N, detail of zooid, showing pellicular striations. O, macronucleus, the trochal band and the scopula. P, oral ciliature. Abbreviations: AR, annular ridge; BD, basal disc; CV, contractile vacuole; En, endostyle; G, germinal kinety; H, haplokinety; LS, longitudinal striae; Ma, macronucleus; Me, mesostyle; Op, operculum; Po, polykinety; P1–3, infundibular polykineties 1–3; Sc, scopula; St, stalk; TB, trochal band; Tu, tube. Scale bars = 30 μm.

Figure 3. Photomicrographs of Pyxicola pusilla in vivo (A–O) and after protargol staining (P–U). A–G, lateral views of different individuals, showing the varieties of body shape, lorica shape and colour, and stalk length; arrows indicate the contractile vacuole. H, I, two constricted individuals. J, apical view of a contracted individual, showing the aperture of lorica and frontal view of operculum. K, L. lateral view of operculum; arrows indicate the depression of operculum border. M, N. posterior portion of individuals; arrows indicate the mesostyle, arrowhead marks the basal disc. O, showing the striations of pellicle. P, Q. two specimens; arrows and arrowheads indicate macronucleus and the trochal band, respectively. R–T, oral ciliature. U, infundibular polykineties 1–3. Abbreviations: G, germinal kinety; H, haplokinety; P1–3, infundibular polykineties 1–3. Scale bars = 30 μm.