Gyratrix hermaphroditus Ehrenberg, 1831

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 : 27

Gyratrix hermaphroditus Ehrenberg, 1831 ( Fig. 13A–C )

Synonyms: Gyrator hermaphroditus Ehrenberg, 1835 .

Gyrator furiosum (Schmidt, 1857) .

Prostomum furiosum Schmidt, 1858 .

Prostomum banaticum Graff, 1875 .

Gyrator banaticus (Graff, 1875) .

Gyratrix hermaphroditicus Luther, 1918 .

Studied material: Thirty-three individuals studied alive, twelve of them were whole mounted (MZUSP PL 2244–2254).

Localities: Site 1 (19/09/2018), Site 2 (30/11/2018; 9/10/2018) and Site 3 (5/06/2019; 24/04/2019), associated with benthal and phytal microhabitats.

Description: Body elongated and whitish, 1.7 mm long and 0.3 mm wide ( Fig. 13A–B ). The male copulatory apparatus has the following dimensions: the prostate stylet III (stalk) is 96.2 ± 16 μm (81.1–127.7 μm; n = 11) long, the stylet sheath is 40.6 ± 14 μm (27.5–66.4 μm; n = 11) long and prostate stylet type II (penis stylet) is 130.5 ± 23.1 μm (109.7–178.4 μm; n = 11) long ( Fig. 13C ).

Taxonomic remarks: The morphology of the male copulatory apparatus, follows the description of the species made by Marcus (1945b), Karling and Schockaert (1977), Artois and Tessens (2008), Rundell and Leander (2014) and Van Steenkiste and Leander (2018). This species is widely distributed and it is found in freshwater, brackish and marine environments. The male copulatory apparatus of individuals from the ESEC Taim are within the ranges of individuals found around the world ( Karling and Schockaert 1977; Jouk and De Vocht 1989; Artois et al. 2000; Artois and Tessens 2008; Rundell and Leander 2014; Van Steenkiste and Leander 2018). However, dimensions and configurations on the male copulatory apparatus and the female reproductive system vary notably within populations. This fact has been observed, suggesting complex species, a hypothesis which has not been formally tested.

Distribution: Widely distributed in freshwater and marine habitats (see Tyler et al. 2016 for a complete overview).

Figures

Fig. 13. Specimens of Polycystididae and Prorhynchidae. (A–C) Gyratrix hermaphroditus: (A) habitus of a live mature animal, (B) schematic representation of the habitus and (C) penis stylet. (D–F) Prorhynchus stagnalis: (D) habitus of live mature individual, (E) detail of the anterior region of the body and (F) stylet.