
Fig. 1
Squalonchocotyle euzeti n. sp. from Dalatias licha off Algeria. A, holotype, whole body. Due to the slender body, only limited anatomy is represented. Asterisk, level of seminal receptacle (outline of seminal receptacle drawn) and ovary. B – G, sclerites. H – J, extremities of sclerites.
For A – J, numbers of sclerites are indicated. K, hamuli of various specimens. A – J, holotype; K, paratypes.

Fig. 2
Squalonchocotyle euzeti n. sp. Anatomy of anterior part of reproductive system
Table 1
“Small” species of Squalonchocotyle. Measurements in various publications
| Species | S. abbreviata | S. centrophori | S. cerfontaini | S. mitsukurii | S. cerfontaini | S. spinacis | S. squali | S. squali | S. squali | S. squali | S. tropai | S. tropai |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Source | Cerfontaine, 1899 | Maillard, 1970 | Maillard, 1970 | Kitamura et al., 2006 | This paper | Goto, 1894 | MacCallum, 1931 | Price, 1942 | Dillon & Hargis, 1968 | Martorelli et al., 2008 | Tendeiro & Valdez, 1955 | Maillard, 1966 |
| Name in source | Onchocotyleabbreviata | Squalonchocotylecentrophori | Squalonchocotylecerfontaini | Squalonchocotylemitsukurii | S. cerfontaini | Onchocotylespinacis | Squalonchocotyle squali | Erpocotyle squali | Erpocotyle squali | Squalonchocotyle squali | Erpocotyle tropai | Squalonchocotyletropai |
| Host name in source | Acanthias vulgaris | Centrophorusgranulosus | Dalatias licha | Squalus mitsukurii | Dalatias licha | Spinax sp | Squalus acanthias | Squalus acanthias | Squalus lebruni | Squalus acanthias | Squalus fernandinus | Squalus fernandinus |
| Host valid name | Squalus acanthias Linnaeus, 1758 | Centrophorus granulosus (Bloch et Schneider, 1801) | Dalatias licha (Bonnaterre, 1788) | Squalus mitsukurii Jordan et Snyder, 1903 | Dalatias licha (Bonnaterre, 1788) | Squalus acanthias Linnaeus, 1758 | Squalus acanthias Linnaeus, 1758 | Squalus acanthias Linnaeus, 1758 | Squalus acanthias Linnaeus, 1758 | Squalus acanthias Linnaeus, 1758 | Squalus acanthias Linnaeus, 1758 | |
| Locality | East Atlantic (Roscoff, France) | Mediterranean (Sète, France) | Mediterranean (Sète, France) | Pacific (Japan) | Mediterranean (Sète, France) MNHN 711 H, Ti 52 | Pacific (Japan) | Several | Atlantic (USA) | Pacific (New Zealand) | Atlantic (Argentina) | Indo-Pacific (Angola) | Mediterranean (Sète, France) |
| n | 7 | 2 | 13 | 1 | several | 13 | 56 | 11 | 2 | 4 | ||
| Total body length | 7,000 – 8,000 | 3,300 – 7,500 | 3,000 | 3,200 – 7,500 | 3,533 | 8,000 – 9,000 | 7,000 – 10,000 | 3,400 – 7,000 | 4,310 – 6,650 | 4,760 – 6,960 | 1,420 – 1,690 | 1,700 – 2,300 |
| Body proper width | 1,000 – 1,500 | 350 | 500 – 1,200 | 407 | – | 1,500 | 765 – 935 | 620 – 1,060 | 62 – 87 | 680 – 690 | 330 – 450 | |
| Anterior sucker diameter | 340 – 420 | 200 | 220 – 228 | 190 – 270 | 200 – 250 | |||||||
| Length | 190 – 350 | 170 | ||||||||||
| Width | 250 – 430 | 218 | ||||||||||
| Pharynx diameter | 120 – 130 | 75 | 50 – 120 | |||||||||
| Pharynx length | 120 | 70 – 120 | 130 | 84 – 117 | 57 – 67 | |||||||
| Pharynx width | 60 | 60 – 120 | 122 | 61 – 69 | 40 – 60 | |||||||
| Haptor length | 900 – 1,400 | 1,000 – 2,800 | 1,147 | 1,300 | 1,120 – 1,260 | 400 – 510 | 546 | |||||
| Haptor width | 700 – 1,000 | 800 – 1,700 | 1240 | 830 – 1,250 | 600 – 660 | 336 | ||||||
| Anterior sclerite length | 650 – 770 | 560 – 650 | 230 – 300 | 654 | 280 | 500 – 600 | 325 – 480 | 570 – 910 | 300 – 350 | |||
| Median sclerite length | 680 – 800 | 580 – 690 | 230 – 300 | 683 | 280 | 500 – 600 | 366 – 480 | 570 – 910 | 290 – 360 | |||
| Posterior sclerite length | 660 – 770 | 560 – 630 | 190 – 238 | 650 | 280 | 430 – 600 | 337 – 494 | 570 – 910 | 310 – 330 | |||
| Appendix length | 400 | 800 – 1,900 | 537 | 765 – 935 | 641 – 925 | 740 – 1,350 | 440 – 450 | 300 – 370 | ||||
| Appendix width | 200 | 250 – 500 | 185 | 255 – 340 | 100 – 210 | 200 – 220 | 200 – 230 | |||||
| Hamulus length | 47 – 61 | 63 – 70 | 55 – 65 | 85 | 40 | 72 | 72 | 61 – 72 | 50 – 70 | 37.5 – 42.5 | ||
| Hamulus outer length | 8 – 16 | 59 | 14 – 18 | |||||||||
| Hamulus inner length | 15 – 23 | 61 | 12 – 14 | |||||||||
| Testes number | 30 – 40 | 100 – 150 | 25 – 40 | 25 | 60 | 40 – 60 | 30 – 69 | numerous | few | |||
| Cirrus bulb | ||||||||||||
| Cirrus length | 650 | 350 | 200 – 370 | 75 – 100 | ||||||||
| Cirrus width | 40 | 60 – 110 | 40 – 50 | |||||||||
| Egg, proper length | 100 | 125 – 360 | 320 | 285 – 340 | 210 – 247 | 250 – 350 | 230 | 220 | ||||
| Egg, filament number & length | 2 | 2 | 2 | 2 | 2; 50 – 60 | 2 | ||||||
| Seminal receptacle length | ||||||||||||
| Seminal receptacle length | 210 – 350 | 241 | 400 – 550 | |||||||||
| Seminal receptacle width | 75 – 160 | 155 | 100 – 150 |
Table 2
“Large” species of Squalonchocotyle. Measurements in various publications and comparison with the new species S. euzeti.
| Species | S. borealis | S. borealis | S. laymani | S. euzeti n. sp. | S. euzeti n. sp. |
|---|---|---|---|---|---|
| Source | Van Beneden, 1853 | Cerfontaine, 1899 | Yamaguti, 1958 | This paper | This paper |
| Name in original description | Onchocotyle borealis | Squalonchocotyle borealis | Squalonchocotyle laymani | ||
| Host name in original description | Scimnus glacialis | Scimnus glacialis | Mustelus manazo | Dalatias licha | Dalatias licha |
| Host valid name | Somniosus microcephalus (Bloch et Schneider, 1801) | Somniosus microcephalus (Bloch et Schneider, 1801) | Mustelus manazo Bleeker, 1855 | Dalatias licha (Bonnaterre, 1788) | Dalatias licha (Bonnaterre, 1788) |
| Locality | Atlantic, North Sea (Belgium) | Atlantic, North Sea (Belgium) | Pacific (Japan) | Mediterranean (Algeria) | Mediterranean (Algeria) |
| n | 6 | 5 | Holotype | 31 paratypes | |
| Total body length | 25,000 – 30,000 | 20,000 (unflattened) | 8,500 – 14,000 | 18,463 | 12,921±3,289 (7,326 – 21,830, n=32) |
| Body proper width | 3,000 – 4,000 | 1,200 – 1,400 | 1,628 | 1,078±239 (777 – 1,813, n = 32) | |
| Anterior sucker diameter | 310 – 390 | ||||
| Anterior sucker length | 306 | 286 (201 – 410, n = 20) | |||
| Anterior sucker width | 366 | 343 (261 – 448, n = 20) | |||
| Pharynx diameter | 70 – 110 | ||||
| Pharynx length | 194 | 179 (112 – 246, n = 21) | |||
| Pharynx width | 149,2 | 164 (119 – 216, n = 21) | |||
| Haptor length | 4,051 | 2,428 (1,758 – 4,051, n = 12) | |||
| Haptor width | 3,552 | 2,450 (1,610 – 3,552, n = 12) | |||
| Anterior sclerite length | 2,228****** | 750 – 920 | 1,638 | 1,763 (1,130 – 2,906, n = 20) | |
| Median sclerite length | 600 – 620 | 1,675 | 1,851 (1,171 – 2,909, n = 20) | ||
| Posterior sclerite length | 600 – 620 | 1,586 | 1,749 (1,089 – 2,738, n = 20) | ||
| Appendix length | 800 – 1,100 | 1,029 | 872 (522 – 1,186, n = 10) | ||
| Appendix width | 400 – 530 | 306 | 207 (142 – 336, n = 10) | ||
| Hamulus length | 40 – 50 | ||||
| Hamulus outer length | 83****** | 87 | 70 (59 – 87, n=13) | ||
| Hamulus inner length | 66****** | 74 | 63 (44 – 74, n = 13) | ||
| Testes number | numerous | 100 or more | 82 | 82 (69 – 96, n = 10) | |
| Cirrus length | 130 – 150 | 307 | 421 (307 – 551, n = 7) | ||
| Cirrus width | 120 – 150 | ||||
| Eggs proper length | 250 | 450 | 539 (463 – 644, n = 5) | ||
| Egg filament number and length | 2; 100 – 150 | 2 | |||
| Seminal receptacle length | 250 – 420 | 410 | 667 (522 – 858, n = 11) |

Fig. 3
Squalonchocotyle euzeti n. sp.
Anatomy of median part of reproductive system