Revision of the systematics of the Polystomoidinae (Platyhelminthes, Monogenea, Polystomatidae) with redefinition of Polystomoides Ward, 1917 and Uteropolystomoides Tinsley, 2017 Author Chaabane, Amira Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Private Bag X 6001, Potchefstroom, Author Preez, Louis Du Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Private Bag X 6001, Potchefstroom, & South African Institute for Aquatic Biodiversity, Private Bag 1015, Makhanda, 6140, South Africa Author Johnston, Gerald Department of Natural Sciences, Santa Fe College, Gainesville, Florida, 32606, USA Author Verneau, Olivier Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Private Bag X 6001, Potchefstroom, & University of Perpignan Via Domitia, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR 5110, 66860, & CNRS, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR 5110, 66860, Perpignan, France text Parasite 2022 Paris, France 2022-12-16 29 56 1 19 http://dx.doi.org/10.1051/parasite/2022056 journal article 10.1051/parasite/2022056 1776-1042 PMC9879127 36562437 12524501 78E47736-5414-4CFC-897D-626DE8130F7D Revision of Uteropolystomoides outlines Polystomoides multifalx , originally described as Polystoma multifalx Stunkard, 1924 from the pharyngeal region of Pseudemys floridana from central Florida ( USA ), was the first A. Chaabane et al.: Parasite 2022, 29 , 56 Table 5. Relative placement of some organs as % measurements from anterior end and average body measurements in micrometer for polystomes collected from Pseudemys nelsoni Carr , originally regarded as Uteropolystomoides nelsoni (Du Preez & Van Rooyen 2015) and from Pseudemys concinna (Le Conte) , originally regarded as Polystomoides stunkardi Harwood, 1931 . The fourth column combines measurements obtained from both samples. Measurements are presented as the range followed in parenthesis by the mean, standard deviation, and sample size.

Morphological characteristics	Sample collected from Pseudemys nelsoni	Sample collected from Pseudemys concinna	Combined set of data
Body length (BL)	4,730–7,745 (6,303 ± 965; 10)	5,408–10,691 (7,182 ± 1,653; 10)	4,730–10,691 (6,743 ± 1,392; 20)
Greatest width (GW)	1,761–2,865 (2,408 ± 373; 10)	1,859–3,058 (2,490 ± 404; 10)	1,761–3,058 (2,449 ± 381; 20)
Vaginal position from anterior as %	29–36% (32% ± 2%; 10)	28–38% (32% ± 3%; 10)	28–38% (32% ± 2%; 18)
BL / GW	2.2–3.9 (2.7 ± 0.5; 10)	2.3–3.6 (2.9 ± 0.4; 10)	2.2–3.9 (2.8 ± 0.5; 20)
Oral disk width	684–1,110 (927 ± 136; 10)	773–1,281 (997 ± 168; 10)	684–1,281 (962 ± 153; 20)
Pharynx length	417–676 (548 ± 77; 10)	455–661 (560 ± 61; 10)	417–676 (554 ± 68; 20)
Pharynx width	619–959 (756 ± 98; 10)	750–954 (822 ± 97; 10)	619–959 (783 ± 93; 20)
Haptor length (HL)	1,202–1,665 (1,423 ± 168; 10)	1,130–2,043 (1,496 ± 270; 10)	1,130–2,043 (1,459 ± 222; 20)
Haptor width	1,756–2,302 (2,070 ± 184; 10)	1,409–2,657 (1,982 ± 356; 10)	1,409–2,657 (2,026 ± 179; 20)
HL as % of BL	17–26 (23 ± 2.9; 10)	16–23 (21 ± 2.0; 10)	16–26% (22% ± 2.6; 20)
Haptoral sucker diameter	343–477 (419 ± 34; 51)	382–462 (418 ± 20; 53)	343–477 (419 ± 28; 104)
Ovary length	164–281 (213 ± 35; 9)	131–350 (258 ± 76; 7)	131–350 (233 ± 59; 16)
Ovary width	91–142 (112 ± 18; 9)	70–192 (139 ± 39; 7)	70–192 (124 ± 31; 16)
Egg length	137–263 (221 ± 49; 11)	241–269 (255 ± 13; 5)	137–269 (232 ± 43; 16)
Egg width	139–180 (160 ± 14; 11)	184–193 (189 ± 4; 5)	137–193 (169 ± 19; 16)
Number of eggs in utero	0–8 (3.4 ± 2.6; 10)	0–12 (3.8 ± 5; 10)	0–12 (3.6 ± 4.1; 20
Vagina length	360–860 (553 ± 124; 20)	353–722 (578 ± 109; 18)	353–860 (565 ± 156; 38)
Genital pore position from anterior as %	18–24% (22% ± 2%; 9)	18–24% (20% ± 2; 10)	18–24% (21% ± 2; 19)
Genital bulb diameter	438–847 (625 ± 130; 10)	498–781 (675 ± 88; 10)	438–847 (650 ± 111; 20)
Genital spines number	123–136 (130 ± 6; 7)	118–124 (120 ± 3; 7)	118–136 (125 ± 7; 14)
Genital spine length	96–98 (97 ± 1; 7)	83–98 (90 ± 5; 13)	83–98 (93 ± 3; 20)
Testis length	342–679 (471 ± 100; 10)	514–892 (628 ± 127; 9)	342–892 (545 ±136; 19)
Testis width	425–778 (617 ± 128; 10)	454–747 (450 ± 111; 9)	425–778 (632 ± 118; 19)
Hamulus handle length	105–145 (121 ± 15; 7)	108–175 (145 ± 22; 12)	105–175 (137 ± 22; 19)
Hamulus guard length	86–120 (104 ± 17; 5)	105–167 (131 ± 23,9; 7)	86–167 (121 ± 24; 12)
Hamulus hook length	60–78 (67 ± 7; 6)	59–86 (73; ± 9; 7)	59–86 (70 ± 9; 13)
Marginal hooklet 1 length	25–30 (28 ± 3; 14)	25–28 (28 ± 0.9; 11)	25–30 (28 ± 2; 25)
Marginal hooklet 2–8 length	25–29 (27 ± 3; 16)	24–29 (28 ± 1.3; 18)	24–29 (27 ± 3; 34)

13 chelonian polystome known to have a huge genital bulb bearing numerous long spines in excess of 100 (120–124) [ 40 ]. Stunkard [ 40 ] mentioned that the number of genital spines of this species was three times greater than in any other known polystomes at the time. Based on samples from the mouth of Pseudemys hieroglyphica Boulenger (now Pseudemys concinna ) from Oklahoma ( USA ), Harwood [ 10 ] distinguished Polystomoides stunkardi Harwood, 1931 from P. multifalx by the fewer genital spines, the smaller size of the genital bulb and testis, and the arrangement of haptoral suckers. From a morphological comparison between a set of specimens collected by Mr. Macintosh from P. floridana from southern Florida and vouchers of P. stunkardi from P. concinna from Oklahoma , Price [ 36 ] proposed the conspecificity of P. stunkardi with P. multifalx . However, Tinsley [ 42 ] concluded that U. nelsoni , P. multifalx , and P. stunkardi may form a coherent group of apparently related species. Based on morphological observations and measurements of samples collected from P. concinna and P. nelsoni ( Table 5 ), we were unable to distinguish polystomes collected from both host species. Moreover, the genetic data indicated that polystome samples collected from the three distinct host species, namely P. concinna , P. floridana , and P. nelsoni , belong to the same polystome species. We therefore agree with Price [ 36 ], and consider that the specimens collected from P. concinna from the Ichetucknee River of Florida and those collected from P. nelsoni are conspecific with P. multifalx . We thus propose to consider a single species, namely Uteropolystomoides multifalx (Stunkard, 1924) n. comb. in the genus Uteropolystomoides and provide below a supplementary description for the new type species.