Ptygura libera Myers, 1934

Wei, Nan, Jersabek, Christian D. & Yang, Yufeng, 2019, Rotifers from China (Western Guangdong Province), with description of Lecane zhanjiangensis sp. nov. (Rotifera: Monogononta: Lecanidae), Zootaxa 4603 (1), pp. 66-80 : 66-80

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Ptygura libera Myers, 1934


Ptygura libera Myers, 1934

( Figs 5–6 View FIGURE 5 View FIGURE 6 )

Redescription of female. Corona ( Fig. 5A, 5E View FIGURE 5 ) large, bilobate (circular corona with a dorsal gap in Myers (1934), misinterpreted trilobate in Nogrady (1976)) with a dorsal indentation and two red apical eyespots. Corona a circumapical band, well developed dorsally, poorly developed latero-ventrally ( Fig. 5E View FIGURE 5 ), interrupted ventrally. One frontal protuberance in contracted stage ( Fig. 5B View FIGURE 5 ). Neck indistinct, and body smoothly tapering into retractable foot of medium length, which terminates in a long peduncle anchoring to a membranous structure ( Fig. 5A, 5F View FIGURE 5 ) connecting to the tube. Head and anterior part of the trunk usually bent dorsally while swimming ( Fig. 5E View FIGURE 5 ). Anus near middle of the trunk, opening upwardly on the dorsal side ( Fig. 5C, 5D View FIGURE 5 ). Lateral antennae long and slender. Tube ( Fig. 5A, F View FIGURE 5 ) transparent oval to pyriform, inner sheath conspicuous, distinct cylindrical, outer layer gelatinous and difficult to see. Usually one or two eggs next to the foot.

Trophi malleoramate ( Fig. 6 View FIGURE 6 ), nearly symmetrical. Unci plates consist of right/left: 14–15/14–15 weakly webbed teeth. Three right and four left major teeth almost straight with long lanceolate head. Minor teeth head sharply pointed. Rami elongate-triangular with short blunt alulae. Median rami apophyses inapparent in caudal view. Basal apophyses moderately developed. Manubria crescent-shaped with three chambers. Fulcrum short, with a weakly developed basal plate.

Comments. This widely-distributed species ( De Ridder & Segers, 1997; Segers, 2007) has previously been recorded from Afrotropical (e.g. Bērziņš, 1982; De Ridder, 1987; Koste & Tobias, 1987; 1989; De Ridder, 1992), Nearctic (e.g. Myers, 1934; Nogrady, 1976; 1983; Stemberger, 1990; Siegfried, 1991; Jersabek et al., 2003), Neotropical (e.g. Koste, 1972; Koste & Jose de Paggi, 1982; Vásquez et al., 1998; Garcia-Morales & Elias- Gutierrez, 2004; Garraffoni & Lourenço, 2012; Ferrando & Claps, 2016), Palaearctic? ( Sudzuki, 1992; Salem et al., 2016) and Oriental ( Umi et al., 2018) regions, with most records from the Nearctic and Neotropis. Ours is the first record for China.

Ptygura libera is known as a warm-stenotherm ( Nogrady, 1976; Koste & Tobias, 1987; Garcia-Morales & Elias-Gutierrez, 2004), that prefers less nutrient rich waters ( Salem et al., 2016; Umi et al., 2018) and tolerates low pH ( Koste, 1972; 1978; Umi et al., 2018). It frequently occurs as a dominant species in lakes and reservoirs etc. (e.g. Nogrady, 1976; Koste & Tobias, 1987; Siegfried, 1991; Stemberger, 1990; Umi et al., 2018). The species was found in summer, when it dominated the rotifer community of the Huguangyan Lake, an oligo-/mesotrophic closed maar lake with relatively low nutrient and chlorophyll content ( Zhang et al., 2015; Chen et al., 2018), confirming the ecological preferences of P. libera .














Ptygura libera Myers, 1934

Wei, Nan, Jersabek, Christian D. & Yang, Yufeng 2019

Ptygura libera

Myers 1934

P. libera

Myers 1934