A revision ofPlectanocotyle(Monogenea, Plectanocotylidae), with molecular barcoding of three species and the description of a new species from the streaked gurnardChelidonichthys lastovizaoff Algeria

Abstract

Background The family Plectanocotylidae includes parasites of the gills of marine fish; although nine genera and about 20 species have been described, almost no molecular information is available. Putting aside Plectanocotyle elliptica Diesing, 1850, supposedly a parasite of the white perch Morone americana, never found again since its original description, two species were valid within Plectanocotyle Diesing, 1850 before this work: Plectanocotyle gurnardi (Van Beneden & Hesse, 1863) Llewellyn, 1941 and Plectanocotyle major Boudaya, Neifar & Euzet, 2006. Methods In this paper, we describe the third species of the genus Plectanocotyle and perform a comparative morphological and molecular analysis of the three species and of Triglicola obscura (Euzet & Suriano, 1974) Mamaev, 1976. Host fishes were also barcoded (COI) for confirmation of host identifications. Results Plectanocotyle lastovizae n. sp. is described from the gills of the streaked gurnard Chelidonichthys lastoviza collected off Algeria. The species is compared with specimens of Plectanocotyle cf. gurnardi (from C. lastoviza) from the same locality and P. major and T. obscura (both from the longfin gurnard C. obscurus). Molecules from Plectanocotyle cf. gurnardi could not be compared with P. gurnardi from the type-host and type-locality and we kept the status of the Mediterranean specimens as pending. Algeria is a new geographic record for P. major and T. obscura. Plectanocotyle lastovizae n. sp. is distinguished from the other species found in the Mediterranean by the measurements of clamps, number of testes, and COI sequences, with notable divergence (7.8–11.8%) from the other two species of the genus. Discussion We briefly present a list of currently known members of the family Plectanocotylidae, their biology and their hosts.

“Something old, something new, something borrowed, and the oioxeny is true”: description of Plectanocotyle jeanloujustinei n. sp. (Polyopisthocotylea, Plectanocotylidae) from the MNHN Helminthology collection with novel molecular and morphological data for P. gurnardi (Van Beneden & Hesse, 1863) (sensu stricto) from Sweden

“… Tunisia, W.M. Source Present study Present study; Ayadi et al (2022) Ayadi et al (2022) Ayadi et al (2022) Boudaya et al (2006) Body L. 1681 (1027–2427, n = 25) 2330 (1900–2800, n = 24) 2120 ± 350 (1100–3000, n = 31) 4020 (3380–4400, n = 5) 1841 (1500–2300, n = 11) Body W. 287 ± 90 (130–475, n = 32) 366 (250–430, n = 24) 310 ± 50 (200–430, n = 31) 472 (370–850, n = 5) 442 (210–600, n = 11) Oral suckers 51 ± 11 (30–70, n = 33) 41 (29–53, n = 21) 38 (30–46, n = 15) 60 (58–62, n = 4) 48 (40–60, n = 22) * × 43 ± 9 (28–64, n = 33) × 30 (20–73, n = 21) × 34 (25–45, n = 15) × 59 (55–62, n = 4) Pharynx 45 ± 10 (30–70, n = 32) 60 (50–77, n = 21) 48 (38–60, n = 15) 69 (68–70, n = 4) 45 (30–70, n = 24) * × 41 ± 9 (2–61, n = 32) × 56 (45–70, n = 21) × 42 (30–56, n = 15) × 69 (67–70, n = 4) Clamp 1 91 (51–115, n = 20) 94 (80–103, n = 10) × 82 (70–90, n = 8) 125 (90–180, n = 11) × 101 (35–135, n = 11 181 (175–195, n = 5) × 139 (125–160, n = 5) 137 (90–160, n = 17) × 110 (85–140, n = 17) × 80 (48–108, n = 20) ...…”

“…In the taxonomy of Polyopisthocotylea, it is recurrent to distinguish species by the cox 1 divergence. Herein, in addition to the morphological differences, the four species of Plectanocotyle differ significantly by the divergence in their corresponding cox 1 sequences ( Table 3 ) especially given that the recent effort by Ayadi et al (2022) encompasses molecular data of thoroughly identified specimens (with complete traceability of host i.e., barcoded hosts and deposited hologenophores) of all currently known members of the genus except P. gurnardi which was completed in this study.…”

“… PP297659-61 , PP297663-65 (6 sequences) Present study Plectanocotyle jeanloujustinei n. sp. Chelidonichthys lastoviza Bouharoun, Algeria, W. M. MW796588-91 , MG761763-64 Ayadi et al (2022) * Plectanocotyle lastovizae Chelidonichthys lastoviza Bouharoun, Algeria, W. M. MG761761-62 , MW796585 Ayadi et al (2022) Plectanocotyle major Chelidonichthys obscurus Bouharoun, Algeria, W. M. MW796592-94 Ayadi et al (2022) Triglicola obscura Chelidonichthys obscurus Bouharoun, Algeria, W. M. MG761765 , MW796584 Ayadi et al (2022) Allogastrocotyle bivaginalis Trachurus picturatus Bouharoun, Algeria, W. M. MN192392 Bouguerche et al (2019) …”

“…This species is of exceptional interest, as it is the only species of the genus for which molecular data are lacking ( Ayadi et al, 2022 ). Most interestingly, Ayadi et al (2022) reported the presence of Plectanocotyle cf.…”

“…This species is of exceptional interest, as it is the only species of the genus for which molecular data are lacking ( Ayadi et al, 2022 ). Most interestingly, Ayadi et al (2022) reported the presence of Plectanocotyle cf. gurnardi on a distinct host-streaked gurnard Chelidonichthys lastoviza (Bonnaterre, 1788) from a distinct locality, western Mediterranean but no further taxonomic decisions could be made in absence of morphological and molecular data for P. gurnardi sensu stricto from its type locality, Northeast Atlantic waters.…”