Monoecocestus sp.2

Martins, Natalia Beatriz Guerreiro, Robles, María Del Rosario, Navone, Graciela Teresa & Callejón, Rocío, 2023, Monoecocestus (Cestoda: Anoplocephalidae) diversity in Sigmodontinae rodents characterized by morphology and molecular methods, Zootaxa 5380 (1), pp. 37-55 : 46

Monoecocestus sp.2

Description (based on three specimens): Scolex 0.27 long by 0.41 wide ( Fig. 1g ). Suckers 0.16 ± 0.01 (0. 17–0. 26) by 0.13 ± 0.01 (0.12–0.14) in diameter. Mature proglottids 0.72 ± 0.32 (0.49–0.94) long by 2.60 ± 0.23 (2.43–2.76) wide ( Fig. 1h ). Genital pores alternate irregularly. Testes number 90 per proglottid, each testis 0,04 ± 0.01 (0.03– 0.05) in diameter. Cirrus sac 0.13 long by 0.36 wide. Vitellarium 0.42 ± 0.25 (0.27–0.71) wide. Ovary 0.63 ± 0.28 (0.32–0.87) wide. Gravid proglottids 1.18 ± 0.01 (1.17–1.18) long by 2.54 ± 0.01 (2.53–2.55) wide. Eggs 43.04 ± 0.09 (42.97–43.10) μm long by 39.10 ± 0.18 (38.97–39.22) μm wide ( Fig. 1i ). Embryophore in form of a pyriform apparatus.

Taxonomic summary

Host: Holochilus chacarius

Locality: Selvas de Río de Oro, Chaco Province

Voucher specimens: MLP-He 7588

Comments. These specimens were classified under the genus Monoecocestus following Beveridge (1994), based on its morphological features, e.g., simple genitalia, genital pores irregularly alternate, internal and external seminal vesicles present, pyriform apparatus present. However, due to inadequate preservation, morphological characteristics of the uterus could not be well observed. Among species with genital pores irregularly alternate, Monoecocestus sp.2 differ from M. eljefe , M. diplomys , M. machadoi , M. minor , M. myopotami , and M. sininterus , by testes number; from M. mackiewiczi , and M. microcephalus by size of scolex and suckers; and from M. andersoni by size of mature proglottids, testes and eggs. In addition, Monoecocestus sp.2 differ from Monoecocestus sp.1 by size of scolex (0.27 x 0.41 vs. 0.11 x 0.14), mature and gravid proglottids (0.72 x 2.60 vs. 0.51 x 1.70; 1.18 x 2.54 vs. 1.17 x 1.85, respectively), testes number (90 vs. 45), and diameter of eggs (43.04 x 39.22 μm vs. 45.5 x 42.8 μm).

Figures

FIGURE 1. Morphological features of Monoecocestus threlkeldi: (a) scolex, (b) mature proglottids, (c) egg; Monoecocestus sp.1: (d) scolex, (e) mature proglottids, (f) egg; Monoecocestus sp.2: (g) scolex, (h) mature proglottids, (i) egg; Monoecocestus sp.3: (j) scolex, (k) mature proglottids, (l) egg.