Morphological and Molecular Characterization of Two New and Two Already Known Species of the Genus Pallisentis (Acanthocephala: Quadrigyridae) from India with an Update in Key to the Species Author Rana, Khushboo 0000-0001-8177-5710 Parasitology Laboratory, Department of Zoology, Panjab University, Chandigarh, 160014, India. rana. khushboo 961 @ gmail. com; https: // orcid. org / 0000 - 0001 - 8177 - 5710 rana.khushboo961@gmail.com Author Kaur, Harpreet Parasitology Laboratory, Department of Zoology, Panjab University, Chandigarh, 160014, India. text Zootaxa 2023 2023-10-05 5352 4 577 593 http://dx.doi.org/10.11646/zootaxa.5352.4.8 journal article 10.11646/zootaxa.5352.4.8 1175-5326 8426654 E6E8FC63-6356-465F-A878-2EA58C993299 Updated key of Rana & Kaur (2021) to the species of the genus Pallisentis 1. Proboscis hooks in second or third circle declining abruptly in size; cement gland usually small, with few giant nuclei..... 2 Proboscis hooks gradually declining in size posteriorly; cement glands usually long, with many giant nuclei............ 14 2. Proboscis hooks in second circle about half as long as hooks in first circle.........................................3 Proboscis hooks in third circle about half as long as hooks in second circle........................................ 5 3. Trunk spines conical and extending to posterior end of males and females; Saefftigen’s pouch absent.............................................................................. Pallisentis ophiocephali (Thapar, 1930) Baylis 1933 Trunk spines Y–shaped not extending to posterior end of males; Saefftigen’s pouch present.......................... 4 4. Proboscis hooks in first circle 70–80 long; hook roots recurved, simple; leminci equal; testes equatorial, 580–620 (anterior) and 510–560 (posterior) long cement gland 470–630 long; Saefftigen’s pouch 320–390 long; female gonopore terminal.................................................................................... Pallisentis panadei Rai, 1967 Proboscis hooks in first circle 100 long; hook roots stubby knobs; lemnisci unequal; testes pre–equatorial, 950 (anterior) and 700 (posterior) long; cement gland 900 long; Saefftigen’s pouch 770 long; female gonopore sub-terminal........................................................................................... Pallisentis basiri Farooqi, 1958 5. Trunk spines conical................................................................................... 6 Trunk spines Y shaped................................................................................ 11 6. Saefftigen’s pouch present in male........................................................................ 7 Saefftigen’s pouch absent in male.........................................................................8 7. Trunk spines in male 21 circles not extending to posterior end; lemnisci equal; cement gland nuclei 18; anterior testis 360, posterior testis 320 (based on the description of male only)........... Pallisentis channai Gupta, Maurya & Saxena (2015) Trunk spines in female 35–75 circles, in male 21–40; cement gland nuclei 6–16 not extending to posterior end; lemnisci equal; anterior testis 270–480, posterior testis 260–440....................... Pallisentis amini Gautam, Misra & Saxena, 2019 Trunk spines in male 27 circles not extending to posterior end; lemnisci unequal; cement gland nuclei 8; anterior testis 490, posterior testis 470 (based on the description of male only)........... Pallisentis vinodai Gupta, Maurya & Saxena (2015) Trunk spines in female 14–49 circles, in male 18–32; cement gland nuclei 10–14; with; males with no post–testicular trunk spines; lemnisci unequal; anterior testis 240–440, posterior testis 210–360..................................................................................................... Pallisentis meyeri Gautam, Misra & Saxena, 2019 8. Trunk spines in many circles, 57–88 in males and 120–149 in females; Saefftigen’s pouch absent......................................................................................... Pallisentis vietnamensis Amin et al., 2000 Trunk spines in fewer circles, up to 27 in males and 36 in females; Saefftigen’s pouch present........................ 9 9. Trunk small up to 2.0 mm long in males and 4.5 mm long in females; proboscis hooks in anterior 2 circles similar in size; trunk with 14–18 circles of spines each with 17–24 spines; cement gland less than 200 long... Pallisentis guntei Sahay et al., 1967 Trunk small up near about 2.0 mm long in males and near about 4.5 mm long in females; proboscis hooks in anterior 2 circles similar in size; trunk with 15–16 circles of spines each with 8–15 spines; cement gland less than 300 long....................................................................................... .. Pallisentis jagani Koul et al., 1991 Trunk larger, 3.4–6.9 mm long in males and 7.3–15.6 mm long in females; proboscis hooks in second circle slightly smaller that hooks in first circles; trunk with 20–27 circles of spines each with up to 12 spines; cement gland 400–973 long.......... 10 10. Female gonopore terminal; length of testes 733–910 (anterior), 785–925 (posterior); cement gland 863–973, and cement reservoir 580–816........................................................ Pallisentis croftoni Mital & Lal, 1976 Female gonopore terminal; length of testes 1400–1750 (anterior), 1050–1350 (posterior); cement gland not mentioned, and cement reservoir 600–950.............................................. Pallisentis fotedari Gupta & Sinha, 1991 Female gonopore terminal; length of testes 492–387 (anterior), 352–434 (posterior); cement gland 434– 611, and cement reservoir not mentioned.................................................. Pallisentis punctatii Gupta et al., 2015 Female gonopore sub–terminal; length of testes 475 (anterior), 437 (posterior), cement gland 400, and cement reservoir 361....................................................................... Pallisentis allahabadi Agarwal, 1958 Female gonopore latero–terminal; length of testes 200–590 (anterior), 200–480 (posterior), cement gland 320–590, and cement reservoir 330–640......................................... Pallisentis lucknowensis Gautam, Misra & Saxena, 2019 11. Trunk spines extending to posterior end of males and females; proboscis hooks 10–12 per circles; hooks in anterior circles larger than 100........................................................ Pallisentis mehrai Gupta & Fatma, 1986 Trunk spines not extending to posterior end of males or females; proboscis hooks 6–10 per circles shorter than 100...... 12 Female less than 4.0 mm long; lemensci ending well above anterior testis, testis small, up to 225(anterior) long; cement gland small, 200–230 long, with 6–8 giant nuclei................................. Pallisentis cavasii Gupta & Verma, 1980 12. Female longer than 4.0 mm long; lemnisci may reach anterior testis; testes between 200 and 910 long; cement glands between 172 and 926 long, with 10–18 giant nuclei each.............................................................13 13. Proboscis hooks 10 per circles; female proboscis receptacle more than 700 mm long; lemnsci ending well above anterior testis................................................................... Pallisentis indica Mital & Lal, 1976 Proboscis hooks 6–10 per circle; female proboscis receptacle less than 400 long; lemnisci extending to mid-anterior testis..................................................................... .. Pallisentis fasciati Gupta & Verma, 1980 14. Trunk spines conical or Y–shaped, extending to posterior end of at least 1 sex.................................... 15 Trunk spines only conical, not extending to posterior end of either sex.......................................... 22 15. Trunk spines conical, extending to posterior end in female only; testes post–equatorial............................. 16 Trunk spines conical or Y–shaped, extending to posterior end of both males and females; testes equatorial.............. 21 16. Cement gland with less than 20 nuclei.................................................................... 17 Cement gland with more than 20 nuclei.................................................................. 18 17. Proboscis hooks in first circles 100 or more long; proboscis receptacle more than 800 long; cement gland with 9–16 giant nuclei; female gonopore terminal......................................... Pallisentis clupei Gupta & Gupta, 1980 18. Proboscis receptacle less than 800 long.................................................................. 19 Proboscis receptacle ranges more than 800 long............................................................ 20 19. Proboscis hooks in first circles less than 100 long; proboscis receptacle less than 500 long; testes more than 500 long; female gonopore sub-terminal....................................... Pallisentis nagpurensis (Bhalerao, 1931) Baylis, 1933 Proboscis hooks in first circles less than 100 long; proboscis receptacle 398–620 long; testes less than 500 long; female gonopore terminal............................................................ Pallisentis roparensis Rana & Kaur 2021 20. Proboscis hooks in first circle less than 100 long; proboscis receptacle 813–972 long; testes more than 1000 long; female gonopore ventro-terminal............................................................ Pallisentis longus n. sp. Proboscis hooks in first circle more than 100 long; proboscis receptacle 340–890 long; testes less than 1000 long; female gonopore ventro-terminal....................................... Pallisentis thapari Gautam, Misra & Saxena, 2019 21. Trunk spines conical, in 28–32 circles in males and 36–76 circles in females; neck separated from proboscis by transverse circular muscle band; cement gland longer than 1.6 mm ......... Pallisentis garuai (Sahay et al., 1971) Jain & Gupta, 1979 Trunk spines Y–shaped, in 16–20 circles in males and 25–30 circles in females; no muscles band between neck and proboscis; cement gland less than 0.6 mm long, 10–12 nuclei............................ Palllisentis guptai Gupta & Fatma, 1986 Trunk spines Y–shaped, in 28–33 circles in males and 24–42 circles in females; muscles band between neck and proboscis; cement gland less than 0.6 mm long, 7–8 nuclei........................... Palllisentis unnaoensis Gautam et al., 2019 22. Males with Saefftigen’s pouch.......................................................................... 23 Males lacking Saefftigen’s pouch.........................................................................28 23. Trunk spines appearing continuous with collar spines........................ Pallisentis magnum Saeed & Bilqees, 1971 Trunk spines well separated from collar spin............................................................... 24 24. Proboscis hooks 10 per circles, each embedded in thickened cuticular rim; trunk spines with cuticular comb like thickening; males with additional circles of post-testicular trunk spines; testes pre–equatorial....................................................................................................... Pallisentis kalariai Khan & Bilqees, 1985 Proboscis hooks 8–10 per circle; no cuticular thickening at base of proboscis hooks or trunk spines; no post–testicular trunk spines; testes not pre-equatorial......................................................................... 25 25. Female trunk spines in 36–73 circles extending to just anterior to posterior end; additional circles of trunk spines at posterior end of female absent; female reproductive system less than 600 long; Female gonopore ventro-terminal...................................................................................... Pallisentis gomtii Gupta & Verma, 1980 Female trunk spines 55–73 circles extending anterior to posterior end; additional 3–4 circles of trunk spines present at posterior end of female; female reproductive system more than 600 long; female gonopore centro–terminal............................................................................................... .. Pallisentis himachalensis n. sp. Female trunk spines in 10–20 circles, extending only to anterior third of trunk; lemnisci unequal; testes small, less than 1.0 mm long.............................................................................................. 26 Female trunk spines in 10–20 circles, extending only to anterior third of trunk; lemnisci equal; testes large, more than 1.0 mm long................................................................................................27 26. Proboscis hooks 8 per circle; female trunk spines in 11 circles, 24–30 in each circle testes post–equatorial; cement gland 208 long with 18 nuclei............................................ Pallisentis chongqingensis Daoyuan & Zikun, 1993 27. Proboscis hooks 8 per circle; testes equatorial; cement gland 2.2–3. 0 mm long...................................................................................................... Pallisentis sindensis Khan & Bilqees, 1987 Proboscis hooks 10 per circle; testes post equatorial; cement gland short, 0.7–1.6 long....................................................................................................... Pallisentis gaboes , Van Cleave, 1928 28. Proboscis hooks 6–7 per circle......................................................................... 29 Proboscis hooks 8–12 per circle......................................................................... 30 29. Proboscis hook 6 per circle; anterior hooks 89–119 long; cement gland with 16 giant nuclei............................................................................................... Pallisentis umbellatus Van Cleave, 1928 Proboscis hook seven per circle; anterior hooks 60–70 long; cement gland with 10–12 nuclei.................................................................................. Pallisentis pesteri (Tadros, 1966) Chowhan et al., 1987 30. Cement glands with 12–14 giant nuclei; lemnisci equal...................................................... 31 Cement glands with 23–25 giant nuclei; lemnisci unequal.................................................... 32 31. Proboscis hooks 8 per circle; collar spines in 6–7 circles in 8–13 circles each with 29–40 spines; trunk spines in 8–13 circles each with 30–41 spines with sclerotized, large, variably shaped beds; testes longer than 0.7 mm ............................................................................................... Pallisentis celatus Van Cleave, 1928 Proboscis hooks 10–12 per circle; collar spines in 15–17 circles each with 18–20 spines; trunk spines in 21–22 (males), 67 (females) circles each with 16–20 simple triangular spines; testes 0.28 mm –0.42 long....... Pallisentis colisai Sarkar, 1954 32. Female gonopore terminal............................................................................. 33 Female gonopore ventro–terminal....................................................................... 34 33. Proboscis hooks 62–64, 49–54,36–46, 24–28 long (from anterior); trunk spines in 25–26 circles, each with 10 spines; female gonopore terminal.................................................... Pallisentis singaporensis Khan & Ip, 1988 34. Proboscis in male 218–281 long; cement gland not more than 1600 long with 18–29 nuclei; anterior testis 489–842 long; posterior testis 437–832 long.................................................... Pallisentis nandai Sarkar, 1953 Proboscis in male 166–218 long; cement gland 884–2500 long with 15–25 nuclei; anterior testis 575–1200 long; posterior testis 520–1100 long........................................................... Pallisentis paranandai Sarkar, 1953