Mesostoma ehrenbergii (Focke, 1836)

Reyes, Jhoe, Binow, Daniela, Vianna, Rogério T., Brusa, Francisco & Martins, Samantha E., 2021, Fig. 12. Majella pristis n in Periclimenaeus djiboutensis Bruce 1970, Zoological Studies 60 (22), pp. 1-33 : 14-16

Mesostoma ehrenbergii (Focke, 1836) ( Fig. 6A )

Synonyms: Planaria ehrenbergii Focke, 1836 .

Mesostomum ehrenbergii Örsted, 1844 .

Mesostoma wardii Woodworth, 1896 .

Studied material: Eighteen individuals studied alive in squashed preparations, six of them fixed in alcohol (MZUSP PL 2260).

Localities: Site 1 (28/02/2019) and Site 2 (9/10/2018), associated with benthal and phytal microhabitats.

Description: Body of live individuals are 5.4 ± 2.3 mm (1.6–8.7 mm; n = 14) long and 1.5 ± 0.7 mm (0.4–2.9 mm; n = 13) wide, flattened and leaf-shaped, yellow-whitish. Round eggs of ± 0.24 mm in diameter ( Fig. 6A ).

Taxonomic remarks: The general appearance and anatomy of our specimens are in accordance with descriptions made for the Neotropical region ( Beauchamp 1939; Marcus 1943 1946; Ponce de León 1985; Noreña-Janssen and Faubel 1992; Gamo and Leal-Zanchet 2004; Noreña et al. 2006b) and other biogeographical regions ( Fuhrmann 1894; Stout 1953; Luther 1963; Young 2001). However, the body size of our specimens is smaller than those described for the Neotropical region by Beauchamp (1939) (9 mm), Marcus (1946) (15 mm), Noreña-Janssen (1995) (8–10 mm) and Gamo and Leal-Zanchet (2004) (3, 4 and 6 mm); but larger than those found in Peru by Noreña et al. (2006b) (1–1.5 mm).

Distribution: Widely distributed in freshwater ponds around the world (see Tyler et al. 2016 for a complete overview).

Figures

Fig. 6. Live specimens of Typhloplanidae. (A) Mesostoma ehrenbergii, dorsal view of a mature individual observed in dark field. (B) Brothromesostoma evelinae, dorsal view. (C–E) Strongylostoma elongatum: (C) dorsal view of a mature specimen, (D) detail of the male copulatory organ (scale bar not available), (E) schematic representation of the habitus.