Dendrorchis pampae sp. n. (Digenea: Gorgoderidae) from Cynopoecilus melanotaenia (Cyprinodontiformes: Cynolebiidae) a killifish from southern Brazil, with an emended diagnosis of Dendrorchis

Abstract

A new species of Dendrorchis is described and compared with others in the genus. The parasites were found in the swim bladder of the annual killifish Cynopoecilus melanotaenia. Hosts were collected from a seasonal wetland in southern Brazil. The main characteristics of D. pampae are: genital pore in the intestinal bifurcation region elongate and lobed vitellaria uterine loops limited to the acetabular region and to the rear end of the body; and wide intestinal caeca. An emended diagnosis of the genus Dendrorchis includes the characteristics of the new species. This is the first record of an adult digenean in an annual killifish from South America.

First report of Dendrorchis retrobiloba Volonterio & Ponce de León, 2005 (Digenea, Gorgoderidae) in Astyanax aff. fasciatus (Cuvier, 1819) (Characiformes, Characidae) from southern Brazil

“…The specimens of D. retrobiloba are easily distinguished from the congeners D. neivai, D. ritata, and D. pampae based on morphological traits such as body shape, the size and shape of the suckers, testes, ovary and, the extension of the uterus (Travassos 1926, Volonterio and Ponce de León 2005, Soofi et al 2016, Monteiro et al 2018. The bodies of D. neivai, D. ritata, and D. pampae are pyriform, whereas D. retrobiloba has an elongated body.…”

“…The diagnosis of the genus Dendrorchis provided by Travassos (1926) was amended recently by Volonterio and Ponce de León (2005), Campbell (2008), andMonteiro et al (2018). Travassos (1926) recognized specimens with a pyriform body, small cirrus sac, branched testes, deeply lobed ovary, and vitellaria occupying all body fields, except for the intercaecal field above the vitellaria.…”

“…This amendment included the broad and foliated hindbody, cirrus sac and seminal receptacle absent, and testes branched. Monteiro et al (2018) further amended the diagnosis to include the presence of a cirrus sac and modify the position of the genital pore.…”

“…Given these slightly different diagnoses of the genus Dendrorchis (Travassos 1926, Volonterio and Ponce de León 2005, Campbell 2008, Monteiro et al 2018, it is necessary to consider the question of the cirrus sac. If the presence of cirrus sac is considered to be a characteristic of Dendrorchis species (Travassos 1926, Volonterio and Ponce de León 2005, Monteiro et al 2018, Dendrorchis would be the only gorgoderine genus to feature this structure (Campbell 2008). All other gorgoderine genera (except Phyllodistomoides Brooks, 1977 [?…”

“…The genus Dendrorchis was proposed by Travassos (1926) to accommodate Dendrorchis neivai Travassos, 1926, a parasite of the swim bladder of Brycon lundii (= Brycon orthotaenia Günther, 1864) from São Paulo state, Brazil. Subsequently, several other Dendrorchis species have been described in fish hosts, including Dendrorchis retrobiloba Volonterio & Ponce de León, 2005 in Astyanax fasciatus (Cuvier, 1819) from Montevideo, Uruguay (Volonterio and Ponce de León 2005), Dendrorchis ritata Soofi, Birmani & Dharejo, 2016 in Rita rita (Hamilton, 1822) from Jamshoro, Pakistan (Soofi et al 2016), and Dendrorchis pampae Monteiro, Wendt & Zebral, 2018in Cynopoecilus melanotaenia (Regan, 1912 from Rio Grande do Sul state, Brazil (Monteiro et al 2018).…”