Testudinella tridentata Smirnov, 1931

Min, Hee-Min Yang and Gi-Sik, 2025, Seven monogonont rotifers newly recorded in Korea (Rotifera: Monogononta), Journal of Species Research 14 (1), pp. 106-115 : 107-108

Testudinella tridentata Smirnov, 1931 ( Fig. 1 ) NjäḏnjḆệ ( ljạ)

Testudinella tridentata Smirnov, 1931: p. 57 , fig. 2.

Testudinella dicella Myers, 1934: p. 5 , figs. 11, 12.

Testudinella paratridentata Wang, 1961: p. 246 , figs. 220a - c.

Testudinella tridentata africana Gillard, 1952: p. 345 , figs. 6, 7.

Testudinella tridentata amazonica Thomasson, 1971: p. 53 , fig. 9.

Testudinella tridentata insulana Bērziņš, 1982: p. 4 , fig. 11.

Material examined. Female , glycerol permanent slide ( NIBRIV0000909858 ). Reservoir in Tongyeong-si, Korea ( 34°53 ʹ 20.2 ʺ N, 128°23 ʹ 50.5 ʺ E), 06 Oct. 2021. Collected by Hee-Min Yang .

Diagnosis. Lorica stiff and dorsoventrally flattened. Lorica 125 - 130 μm in length, and 75 - 80 μm in width. Anterior margin of dorsal lorica with one median spine and two lateral spines. Anterior margin of ventral lorica with two ridges flanking median notch. Ventral side of lorica with two longitudinal ridges. Foot opening rounded rectangular, projecting to posterior end of lorica. Lateral antennae at widest part of dorsal lorica. Dorsal antenna at upper third of dorsal lorica. Trophi malleoramate type. Manubrium crescent-shaped with three chambers. Fulcrum short and trapezoid-shaped in lateral view. Each uncus with 9 teeth. Rami halfmoon shape with scleropili. Short, symmetrical alulae at distal side of each ramus.

Distribution. Cosmopolitan ( Segers, 2007).

Remarks. Testudinella tridentata represents the sixth species of this genus recorded in Korea. This species exhibits a high degree of variation in the anterior margin of the lorica ( Koste, 1978). It has been recorded worldwide at both the species and subspecies levels, with variations in the shape of the anterior margin ( Jersabek and Leitner, 2013). These variants include T. dicella Myers, 1934 , T. paratridentata Van, 1961, T. tridentata africana Gillard, 1952 , T. tridentata amazonica Thomasson, 1971 , and T. tridentata insulana Bērziņš, 1982 . However, only T. tridentata is currently recognized as a valid species, with the other species considered synonyms ( Segers, 2007). The anterior margin of the Korean specimen examined closely aligns with the original description of the species, particularly in the shape of the dorsal median spine, ventral ridges, outline of the lorica, and shape of the foot opening ( Smirnov, 1931).

Order Ploima Hudson & Gosse, 1886 șḍậ

Family Brachionidae Ehrenberg, 1838 DŔḆệ ⁂

Figures

Fig. 1. SEM images of Testudinella tridentata Smirnov, 1931. A. habitus, ventral view; B. habitus, dorsal view; C. trophi, dorsal view; D. trophi, ventral view.