Molecular evidence for resurrection of Plesiochorus elongatus (Digenea: Gorgoderidae): An urinary bladder parasite of sea turtles

Abstract

Trematodes of the genus Plesiochorus were recovered from the urinary bladder of a stranded female adult loggerhead sea turtle, Caretta caretta, on a beach in Rio de Janeiro State, Brazil. Morphological analysis of the specimens revealed characteristics resembling the sub-species Plesiochorus cymbiformis elongatus rather than the recently synonymised Plesiochorus cymbiformis. Molecular phylogenetic analysis of the ITS2 region also showed that P. c. elongatus was distinct from P. cymbiformis and related taxa. Further analysis of the ITS2 revealed substantial differentiation between P. cymbiformis from the USA and Brazil and the newly sequenced P. c. elongatus from Brazil, while a previously unspecified Plesiochorus sp. from the USA closely related to the novel Brazilian P. c. elongatus was reconciled as a USA isolate of P. c. elongatus. Based on both the morphological and molecular data it is suggested

Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901 (Digenea: Gorgoderidae) in Olive Ridley Sea turtles Lepidochelys olivacea (Eschscholtz, 1829) (Testudines: Chelonidae) from the Brazilian coast: New geographic occurrence and associated injuries

“…Plesiochorus cymbiformis is very similar to P. elongatus, as described by Werneck et al (2019), two morphological characteristics are accepted to differentiate these species: P. elongatus has a more elongated body and the uterine loops end closer to the body edge in the posttesticular region, there is practically no space between the body edge and the loops uterine On the other hand, P. cymbiformis has a less elongated body and the uterine loops have a space between the sides of the body posterior to the testicles. In this note, the assessed parasites (Fig.…”

“…The species was better studied later by Sonsino (1893), Stossich (1895, 1897), Braun (1899), who expanded the descriptions for the species and, later Looss, (1901,1902), who presented the Plesiochorus genus (species type P. cymbiformis). Two species are currently accepted for the genus, the first comprising P. cymbiformis, described in green turtles from Egypt, India, Italy, Panama and the USA, in hawksbill turtles from India, Puerto Rico and the USA, in loggerhead turtles from Australia, Brazil, Egypt, Spain, Greece, Italy and the USA, and in Olive Ridley sea turtles from Costa Rica, Japan and Mexico (see Blair & Limpus, 1982), and the second, Plesiochorus elongatus Pigulevsky, 1953, described in loggerhead turtles from Egypt and Brazil (Werneck et al, 2019).…”

“…The report by Werneck et al (2019) was used for comparisons with other members of the genus (i.e., P. elongatus).…”

“…The helminth fauna of Olive Ridley sea turtle, Lepidochelys olivacea (Eschscholtz, 1829) (Testudines: Chelonidae) has a gap of knowledge in Brazilian coast (Werneck & Silva 2016), and only Pyelossomum cochlear Looss, 1899 (Digenea: Pronocephalidae) has been described for this host so far in this area (Werneck et al, 2015). The genus Plesiochorus Looss, 1901 (Digenea: Gorgoderidae) is a exclusive parasite of sea turtles and only two species are currently accepted, Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901, described in the green sea turtle Chelonia mydas Linnaeus, 1758 (Testudines: Chelonidae), the loggerhead sea turtle Caretta caretta Linnaeus, 1758, the Hawksbill sea turtle Eretmochelys im-bricata (Linnaeus, 1766) and in the Olive Ridley sea turtle (Blair & Limpus, 1982), and Plesiochorus elongatus Pigulevsky, 1953, described in loggerhead turtles (Werneck et al, 2019). Concerning the Neotropical region (see Werneck & Silva, 2016), P. cymbiformis has been described in green turtles from Panama (Caballero & Caballero, 1954) and Brazil (Binoti et al, 2016), in hawksbill turtles from Puerto Rico (Fischthal & Acholonu, 1976), in loggerhead sea turtles from Brazil (Werneck et al, 2018) and in Olive Ridley sea turtles from Costa Rica (Santoro & Morales, 2007), while P. elongatus has been reported in loggerhead turtles in Brazil (Werneck et al, 2019).…”

“…The genus Plesiochorus Looss, 1901 (Digenea: Gorgoderidae) is a exclusive parasite of sea turtles and only two species are currently accepted, Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901, described in the green sea turtle Chelonia mydas Linnaeus, 1758 (Testudines: Chelonidae), the loggerhead sea turtle Caretta caretta Linnaeus, 1758, the Hawksbill sea turtle Eretmochelys im-bricata (Linnaeus, 1766) and in the Olive Ridley sea turtle (Blair & Limpus, 1982), and Plesiochorus elongatus Pigulevsky, 1953, described in loggerhead turtles (Werneck et al, 2019). Concerning the Neotropical region (see Werneck & Silva, 2016), P. cymbiformis has been described in green turtles from Panama (Caballero & Caballero, 1954) and Brazil (Binoti et al, 2016), in hawksbill turtles from Puerto Rico (Fischthal & Acholonu, 1976), in loggerhead sea turtles from Brazil (Werneck et al, 2018) and in Olive Ridley sea turtles from Costa Rica (Santoro & Morales, 2007), while P. elongatus has been reported in loggerhead turtles in Brazil (Werneck et al, 2019). This note describes the fi rst occurrence of P. cymbiformis in Brazil, in the urinary bladder of two Olive Ridley sea turtles found off the Brazilian coast, also reporting tissue organ alterations.…”