Plectanocotyle jeanloujustinei, Cappelletti & Bouguerche, 2024

Cappelletti, Alice & Bouguerche, Chahinez, 2024, “ 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, International Journal for Parasitology: Parasites and Wildlife 23, pp. 100914-100914 : 100914-

4.1. Differential diagnosis of Plectanocotyle jeanloujustinei n sp.

Plectanocotyle jeanloujustinei n. sp. differs from P. lastovizae from the same host C. lastoviza by having larger oral suckers (30–70 × 28–64 vs. 30–46 × 25–45), larger pharynx (50–77 × 45–70 vs. 38–60 × 30–56), and larger clamps (80–103 × 70–90 vs. 90–180 × 35–135). Plectanocotyle jeanloujustinei n. sp. can also be distinguished from P. lastovizae by having a shorter terminal lappet (50–115 vs. 160–375), smaller lateral hamuli (23–53 vs. 42–62), and smaller median hamuli (20–51 vs. 45–60). The two species can be easily differentiated by P. jeanloujustinei

n. sp. having more testes (14–35 vs. 11–15). Additionally, the divergence between the two species in their cox 1 sequences is 10–11 % in p-distances and 11–12 % in K 2P.

Plectanocotyle jeanloujustinei n. sp. can be distinguished from P. major from C. obscurus by having smaller oral suckers (30–70 × 28–64 vs. 58–62 × 55–62), smaller clamps (80–103 × 70–90 vs. 175–195 ×

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125–160), larger terminal lappet (50–115 vs. 56–75), smaller median hamuli (20–51 vs. 27–86), smaller lateral hamuli (23–53 vs. 37–88), and smaller postero-lateral uncinuli (6–15 vs. 8–20). Plectanocotyle jeanloujustinei n. sp. can also be easily distinguished from P. major by having more testes (14–35 vs. 19–20). Moreover, despite sharing the same locality (Western Mediterranean), the hosts are different ( C. lastoviza for P. jeanloujustinei n. sp. vs. C. obscurus for P. major ). Most importantly, P. jeanloujustinei n. sp. and P. major differ in their cox 1 sequences by 10–11 % in both K2P and p-distances.

Plectanocotyle jeanloujustinei n. sp. differs from P. gurnardi sensu stricto from E. gurnardus by having smaller oral suckers (29–53 × 20–73 vs. 30–70 × 28–64), smaller terminal lappet (50–115 vs. 73–302), smaller median hamuli (20–51 vs. 32–59), smaller lateral hamuli (23–53 vs. 41–82). Plectanocotyle jeanloujustinei n. sp. is easily distinguished by having smaller peripheral spines (90–125 vs. 144–261) and smaller median spines (75–97 vs. 91–149) at the level of the male copulatory organ. Plectanocotyle jeanloujustinei n. sp. is easily distinguished from P. gurnardi sensu stricto by having more testes (14–35 vs. 17–27). Additionally, the type-hosts are different ( C. lastovizae for P. jeanloujustinei n. sp. vs. E. gurnardus for P. gurnardi ) and the localities are distinct (Western Mediterranean for P. jeanloujustinei n. sp. vs. Northeast Atlantic for P. gurnardi ). Furthermore, the cox 1 divergence between P. jeanloujustinei n. sp. and P. gurnardi is 8 % in both K2P and p-distances.