Pseudokeronopsis sepetibensis, Wanick & Silva-Neto, 2004

Wanick, Rodrigo Cunha & Silva-Neto, Inácio Domingos Da, 2004, Benthic ciliates from Sepetiba Bay (Rio de Janeiro, Brazil) with description of Pseudokeronopsis sepetibensis n. sp. (Spirotrichea: Urostylida), Zootaxa 587 (1), pp. 1-11 : 6-7

Description of Pseudokeronopsis sepetibensis n. sp.

Diagnosis

Body size 100–140 m long x 20–26 m wide, elongated and dorsoventrally flattened, with round ends. Strangled right above the posterior end ( Figs. 2a, 2b, 2d, 2e, 5 and 7 ). Cytoplasm fully pigmented in light yellow­greenish coloration. Three contractile vacuoles present, arranged in a longitudinal row by the left margin of body, near its median region ( Figs. 2a, 4 ). Ventral ciliature showing inconspicuous bicorona and mid­ventral row.

Morphology

The adoral zone of membranelles, composed of 38–55 membranelles, shows an intermembranellar interruption by the side of the anterior frontal cirri ( Figs. 3, 5 ). No buccal cirri were observed. The size of the external oral membrane is approximately half the size of the internal oral membrane ( Figs. 2b, 3 ).

The number of left marginal cirri ranges from 27–66, and the number of the right marginal cirri ranges from 29–65. Both marginal rows end before the posterior end of body ( Fig. 2b, 5 ). The mid­ventral cirri compose a row of 37– 44 cirri. These cirri are disposedanteriorly in a discrete zig­zag pattern, and after the oral region, become aligned in a straight line that ends up near the three transverse cirri ( Figs. 2b, 6, 7 ). In the dorsal surface, the somatic ciliature is formed by four to six rows of kineties ( Fig. 2d ). The nuclear apparatus is composed by 22–25 ovoid shaped macronuclear nodules, with diameters ranging from 2–5µm. The observation of the micronuclei was made difficult by the presence of so many macronuclear nodules ( Figs. 2e, 6 ).

Species name was created because of locus typicus: Sepetiba Bay , located in Rio de Janeiro state .

Slides containing the holotype and paratypes of P. sepetibensis n. sp. were deposited in the collection of Lab. de Protistologia, Instuto de Biologia, Universidade Federal do Rio de Janeiro – UFRJ .

Figures

FIGURES 2–7: 2: schematic drawings of Pseudokeronopsis sepetibensis n.sp. – a) in vivo ventral side; b) ventral side after protargol impregnation; c) close view of the anterior region of ventral side d) dorsal side; e) ventral side showing the macronuclei. 3: Photomicrograph of the anterior region. 4: Photomicrograph of the ventral side showing the contractile vacuoles. 5–7: Photomicrograph of silver impregnated specimens of ventral side – 5: P.sepetibensis total view showing left marginal cirri and right marginal cirri; 6: close view of the midi region; 7: Close view of the posterior region showing transverse cirri. Legends: AZM: adoral zone of membranelles; AFC: anterior frontal cirri; CV: contractile vacuole; DK: dorsal kineties; FTC: frontoterminal cirri; LMC: left marginal cirri; Ma: macronuclei; MVC: mid­ventral cirri; OM: oral membranelles; PFC: posterior frontal cirri; RMC: right marginal cirri; TC: transverse cirri; MIT: intermembranellar interruption.