Leiotrocha patellae (Cuenot, 1891)

Van As, Liesl L., Basson, Linda & Van As, Jo G., 2017, Mobiline Peritrichs (Ciliophora) Limpets Collected from the Gills of African, Acta Protozoologica 56 (4), pp. 245-254 : 246-247

Description of Leiotrocha patellae from South African limpets ( Figs 1A–D , 2A, C, E )

Host: Cellana radiata capensis (Gmelin, 1791)

Locality: Bazley (30°22′S, 30°40′E), east coast of South Africa

Other host and locality: Scutellastra exusta (Reeve, 1854) ; Mission Rock at St Lucia Reference material: S96/10/10-30; S96/10/ 10-35 in the collection of the Department of Zoology & Entomology, University of the Free State, Aquatic Ecology division Position on host: Gills of limpets

Short cylindrical body with elevated convex peristome ( Fig. 1A ). Adoral spiral turns 405° before plunging into infundibulum ( Figs 1B , 2E ). Haplokinety begins before polykinety, latter enters infundibulum first, followed by haplokinety ( Fig. 2E ).

Pellicle of most individuals smooth ( Fig. 1A ). Aboral ciliary girdle consists of single row of marginal cilia, separated by prominent but thin membrane from compound ciliary wreath with eight kinetosomes and single basal cilia ring, latter again separated by a prominent membrane from ciliary girdle ( Fig. 1A ).

Adhesive disc with scopular cilia ring proximal to denticle ring. Scopular cilia 2 µm in length, grouped in pairs ( Fig. 1D ). Denticles smooth, overlapping like roof tiles ( Figs 1C , 2A ). Anterior apophysis bluntly rounded, fitting closely against preceding denticle. Distal margin parallel to border membrane ( Figs 1D , 2A ). Proximal margin not parallel to distal margin, sloping in posterior distal direction. Central part tapers to sharp point. Conical part ( Fig. 1C ) extends past next denticle adorally for about one quarter length of denticle. Distal central part forming indentation at point of articulation with following denticle. Striated membrane consisting of radial pins 0.8 µm wide, extending past denticle to almost centre of adhesive disc ( Fig. 1C ).

Complex macronucleus ( Fig. 2C ) in shape of rounded A, consisting of granular lateral lobes with thin connections, meeting in round to oval robust central part. Latter lies closer to aboral side of body, with lateral lobes situated more adorally. In some individuals, lobes appear almost fused at one end, with opposite ends wide apart. Small, round to oval micronucleus lying either in closed or open sector of A-shaped macronucleus ( Fig. 2 ). Central part of macronucleus lying more or less in middle of denticle ring, with lateral lobes closer to periphery of body. Diameter of outer margins of macronucleus larger than adhesive disc diameter. Body measurements and denticle information summarised in Table 1.

Figures

Fig. 1. Scanning electron micrographs of Leiotrocha patellae (Cuénot, 1891) collected from Cellana radiata capensis (Gmelin, 1791) (A–D) from Bazley, South Africa and Patella depressa Pennant, 1777 (E–F) from Gorée Island, West Africa. A and E: Body form with aboral (arrows) and adoral ciliary wreath; B:Adoral view of spiral and ciliary wreath just visible; C: Denticle ring (arrow), soft part dissolved, and striated membrane exposed (arrow); D and F: Scopular cilia (arrow). Scale bar:A, B, E, F = 10 µm; C, D = 2 µm.

Fig. 2. Light micrographs of Leiotrocha patellae (Cuénot, 1891) collected from Cellana radiata capensis capensis (Gmelin, 1791) (A, C, E) from Bazley, South Africa and Patella depressa Pennant, 1777 (B, D, F) from Gorée Island, West Africa.A and B: Denticle ring; C and D: Nuclear apparatus – arrow indicate micronucleus; E: Adoral spiral, infundibulum; F: Adoral spiral and body inclusions (arrow). Scale bar:A, B, E, F = 10 µm; C, D = 2 µm.