Rhynchoclevelandella hastula ( Kidder, 1937 )

Kotyk, Michael, Bourland, William A., Soviš, Matyáš, Méndez-Sánchez, Daniel, Škaloud, Pavel, Varadínová, Zuzana Kotyková & Čepička, Ivan, 2024, Morphology maưers: congruence of morphology and phylogeny in the integrative taxonomy of Clevelandellidae (Ciliophora: Armophorea) with description of six new species, Zoological Journal of the Linnean Society 202 (1), pp. 1-51 : 21

Rhynchoclevelandella hastula ( Kidder, 1937)

( Figs 21L–T , 22 ; Supporting Information, Table S24)

Rhynchoclenelandella hastula was detected and morphologically characterized in one host population (PGW). The ciliate was present in every dissected PGW individual and moderately abundant.

Description based on PGW population: Small- to medium-sized Clevelandellidae (on average 86 × 31 µm in vivo, 80 × 28 µm excluding single unusually large (142 × 53 µm) individual, range 62–142 × 23–53 µm; on average 82 × 24 µm in protargol preparations, range 64–94 × 18–31 µm). Slender spear or spade shape (L/ W 2.5 –3.4 in vivo, 2.9– 4.2 in protargol preparations), left-sided notch at base of peristomial projection ( Fig. 21L , M, P), inconspicuous or absent in smaller cells ( Fig. 21N , Q). Posterior peristomial projection conspicuously elongated (about 40% of cell length on average), typically curves rightward ( Fig. 21L , M, N, P, Q), in large cells visibly curved in last third ( Fig. 21L , M). Macronucleus broadly ellipsoidal, posterior end sometimes pointed ( Fig. 21P , S). Karyophore rarely visible, attached to posterior end of macronucleus ( Fig. 21O , S). Micronucleus ellipsoidal, about 5.1 µm across. Somatic cilia limited to approximately anterior 60% of cell length. Dorsal kineties almost straight in protargol preparations ( Fig. 21R ). Free right sutural kinetofragments present ( Fig. 21P ). Adoral zone extends about 44% of cell length on average, composed of an average of 26 membranelles (range 23–28).

Regarding measured characteristics (Supporting Information, Table S24), our population is slightly broader than that ofKidder (1937) (L/ W 2.8 in vivo, 3.4 in protargol preparations vs. 3.8).

Figures

Figure 21. Rhyncholevelandella sp.2 (A–C, G–I) from ASS. Rhynchoclevelandella nipponensis (D–F, J, K) from PAC.Rhynchoclevelandella hastula (L–T) from PGW. In vivo (A–F, L–O) and after protargol impregnation (G–K, P–T). A, ventral view (optical section) showing margin of the peristomial overture (black arrowhead) and adoral membranelles (black arrow). B, ventral view.C, ventral view showing cilia of circumperistomial kineties (white arrowhead). D, ventral view showing anterior margin of peristomial overture (black arrowhead). E, same cell showing ventral kineties (asterisk).F, ventral view showing contractile vacuole (white arrowhead), the relatively large micronucleus

Figure 22. Clevelandella hastula in the scanning electron microscope.From PGW.A, ventral view showing collapsed left lobar protrusion (black arrow), right margin of the peristomial overture (black arrowhead), left-hand spiralling unciliated part of ventral kineties (white arrowhead), and cilia of adoral membranelles (white arrow). B, dorsal view showing left lobar protrusion (black arrow) and unciliated parts of dorsal somatic kineties (black arrowhead) on the characteristically elongated peristomial protrusion (white arrow). C, left lateral view of posterior part of cell showing cilia protruding from the cytoproct on the dome of the left lobar protrusion (black arrow), the anterior margin of the peristomial overture (black arrowhead), cilia of the adoral membranelles (small black arrow), cilia of the circumperistomial kineties (white arrow), and the inconspicuous left posterior suture (white arrowhead) between dorsal kineties (black asterisk) and ventral kineties (white asterisk).Scale bars: 20 µm.