Metadinium medium, Awerinzew and Mutafowa, 1914

Gürelli, Gözde & Akman, Fatma Tül Büşra, 2017, Rumen Ciliate Biota of Domestic Cattle (Bos taurus taurus) in İstanbul, Turkey and Infraciliature of Metadinium medium (Entodiniomorphida, Ophryoscolecidae), Acta Protozoologica 56 (3), pp. 171-180 : 172-176

Infraciliature of Metadinium medium ( Entodiniomorphida , Ophryoscolecidae )

The buccal infraciliature was composed of three polybrachykineties, a kinety loop, and paralabial kineties. The adoral and dorso-adoral polybrachykineties surrounded the vestibular opening, a kinety loop connected them, and the vestibular polybrachykinety extended inside the vestibulum. The wide, adoral polybrachykinety encircled most of the circumference of the vestibular opening, which arched ventrally from its right to left side, and inclined ventrally. The large dorso-adoral polybrachykinety was located at the dorsal side of the vestibular opening. The adoral polybrachykinety and the dorso-adoral polybrachykinety were connected by a kinety loop. This kinety loop was a very narrow polybrachykinety by kineties in which each kinety row decreased in length. The vestibular polybrachykinety extended along the dorsal wall of the vestibulum from the dorsal edge of the vestibular opening to the level of the anterior part of the macronucleus. The vestibular polybrachykinety had a gentle S-shaped curve. Paralabial kineties were observed along the ventral side of the adoral polybrachykinety. The number of these kineties was four. Kinetids in the paralabial kineties were slightly larger than the kinetids in the other polybrachykineties. The dorsal polybrachykinety extended laterally along the dorsal side of the body ( Figs 1 , 2).

Division was by transverse binary fission, perpendicular to the longitudinal axis. The buccal and dorsal polybrachykineties of the opisthe formed without any relationship to the polybrachykineties of the proter. Division began when the three ciliary bands appeared. Three ciliary bands; that is, the dorsal, ventral, and left primordia, were composed of numerous short, oblique kineties during division. The right end of the ventral primordium extended dorsally as a band that was narrow in the middle and wide at its extremity. The widened part of the ventral primordium extended and grew into a right primordium. The ventral and right primordia were connected by a narrow polybrachykinety. The primordium of the paralabial kineties arose along the ventral side of the ventral primordium. The left primordium was at the same level of the ventral and dorsal primordium and under the right primordium. The left primordium tilted obliquely relative to the longitudinal axis of the body. The right primordium and the dorsal extremity of the left primordium approached each oth- er. The ventral, right, left, and dorsal primordia develop into adoral, dorsoadoral, vestibular, and dorsal polybrachykineties of the opisthe, respectively, after binary fission. The kinety loop of the opisthe originated from the kineties between the ventral and right primordia ( Fig. 3 ).

Figures

Fig. 1. Schematic figure of infraciliature of Metadinium medium from the right side, after pyridinated silver carbonate impregnation. AP – adoral polybrachykinety, DAP – dorso-adoral polybrachykinety, DP – dorsal polybrachykinety, KL – kinety loop, PK – paralabial kineties, VP – vestibular polybrachykinety.

Fig. 3. Photomicrographs of M. medium in binary fission from the right side, after pyridinated silver carbonate impregnation. AP – adoral polybrachykinety, DAP – dorso-adoral polybrachykinety, DP – dorsal polybrachykinety, DPR – dorsal primordium, KL – kinety loop, LP – left primordium, NP – narrow polybrachykinety between ventral and right primordia, PK – paralabial kineties, RPR – right primordium, VP – vestibular polybrachykinety, VPR – ventral primordium.