Selfcoelum Dronen, Gardner & Jiménez, 2006

Dronen, Norman O. & Blend, Charles K., 2015, Updated keys to the genera in the subfamilies of Cyclocoelidae Stossich, 1902, including a reconsideration of species assignments, species keys and the proposal of a new genus in Szidatitreminae Dronen, 2007, Zootaxa 4053 (1), pp. 1-100 : 31-32

Key to the species of Selfcoelum Dronen, Gardner & Jiménez, 2006

1a. Rudimentary oral sucker absent......................................................................... 2

1b. Rudimentary oral sucker present....................................................................... 17

2a. Uterine loops commonly overlapping ceca laterally, sometimes approaching the body wall.......................... 3

2b. Uterus largely intercecal............................................................................... 7

3a. Eggs relatively large, greater than 128 µm x 74 µm......................................................... 4

3b. Eggs relatively small, less than 126 µm x 70 µm........................................................... 6

4a. Cirrus sac surpassing level of intestinal bifurcation overlapping ceca posteriorly; ovary near mid-level of intertesticular space or more anterior............................................... S. limnodromi Dronen, Gardner & Jiménez, 2006

4b. Cirrus sac not surpassing level of intestinal bifurcation not overlapping ceca posteriorly; ovary in close proximity to posterior testes below mid-level of intertesticular space.............................................................. 5

5a. Intertestiscular space relatively long, 1,200 µm, about 7% of body length; maximum egg size 175 µm x 93 µm.......................................................................................... S. turusigi ( Yamaguti, 1939)

5b. Intertestiscular space relatively short, 560 µm, about 4% of body length; eggs 165 µm x 85 µm................................................................................................... S. brasilianum ( Stossich, 1902)

6a. Body relatively long, 16,900–19,100 µm; intertesticular space relatively short, 550 µm, about 5% of body length.................................................................................... S. ovopunctatum ( Stossich, 1902)

6b. Body relatively short, 13,000 µm; intertesticular space relatively long, 1,400–1,500 µm, 10–12% of body length........................................................................................... S. lobatum ( Khan, 1935)

7a. Cirrus sac not surpassing level of intestinal bifurcation, not overlapping ceca posteriorly............................ 8

7b. Cirrus sac surpassing level of intestinal bifurcation, overlapping ceca posteriorly.................................. 9

8a. Intertesticular space relatively long, 1,080 µm, about 11% of body length; ratio of width of ovary to mean testicular width 1:1.5............................................................................ S. exile ( Stossich, 1902)

8b. Intertesticular space relatively short, 580 µm, about 4% of body length; ratio of width of ovary to mean testicular width 1:2.6............................................................................. S. vicarium ( Arnsdorff, 1908)

9a. Eggs relatively small, less than 113 µm long.............................................................. 10

9b. Eggs relatively large, more than 116 µm long............................................................. 12

10a. Body unusually small, 5,600 µm long; intertesticular space relatively short, about 295 µm, approximately 5% of body length................................................................................ S. lahillei ( Dollfus, 1948)

10b. Body relatively large, more than 10,000 µm long; intertesticular space relatively long, more than 800 µm, 8–9% of body length.................................................................................................. 11

11a. Body relatively large, 14,000–27,500 µm long; pharynx unusually large, 705–1,049 µm wide... S. goliath ( Witenberg, 1923)

11b. Body relatively small, 11,200 µm; pharynx relatively small, 200 µm wide................... S. makii ( Yamaguti, 1933)

12a. Cirrus sac relatively long; 1,000 µm or more, about 10–11% of body length..................................... 13

12b. Cirrus sac relatively short; 800 µm or less, 5% of body length or less.......................................... 14

13a. Esophagus relatively short; cirrus sac largely situated posterior to intestinal bifurcation........ S. orientale ( Skrjabin, 1913)

13b. Esophagus relatively long; cirrus sac largely situated anterior to the intestinal bifurcation....... S. odeningi ( Dubois, 1965)

14a. Intertesticular space relatively extensive with 5–9 uterine loops present........................................ 15

14b. Intertesticular space relatively unextensive with 1–2 uterine loops present...................................... 16

15a. Anterior extent of vitelline fields reaching to or nearly to the posterior margin of the pharynx; eggs 60–75 µm wide................................................................................. S. lamothei Blend & Dronen, 2008

15b. Anterior extent of vitelline fields terminating near level of intestinal bifurcation; eggs 80 µm or more wide........................................................................................ S. problematicum ( Stossich, 1902)

16a. Posterior most uterine loops encircling posterior testis reaching nearly to posttesticular space..................................................................................................... S. toratsugumi ( Morishita, 1924)

16b. Posterior most uterine loops terminating anterior to posterior testis............... S. orientale eurhinus (Tubangui, 1932)

17a. Uterine loops commonly overlapping ceca laterally, sometimes approaching the body wall......................... 18

17b. Uterus largely intercecal............................................................................. 21

18a. Ventral sucker present....................................................... S. sinhaladvipa ( Fernando, 1950)

18b. Ventral sucker absent................................................................................ 19

19a. Intertesticular space relatively long, 1,000 µm or more, 10% of body length or more.......... S. obliquum ( Harrah, 1921)

19b. Intertesticular space relatively short, 900 µm or less, 8% of body length or less................................... 20

20a. Pharynx unusually large, 500 µm or more wide...................................... S. japonicum ( Kurisu, 1932)

20b. Pharynx relatively small, 150–280 µm wide........................................... S. allahabadi ( Khan, 1935)

21a. Ventral sucker present........................................................... S. theophili ( Dollfus, 1948)

21b. Ventral sucker absent................................................................................ 22

22a. Oral sucker (about 1,000 µm wide) and pharynx (about 1,700 µm wide) unusually large..................................................................................................... S. paradoxum (Marcó del Pont, 1926)

22b. Oral sucker (300 µm wide or less) and pharynx (400 µm wide or less) relatively small............................ 23

23a. Oral sucker unusually small, about 40 µm wide; pharynx/oral sucker ratio about 1:6.9........... S. capellum ( Khan, 1935)

23b. Oral sucker relatively large, about 300 µm wide; pharynx/oral sucker ratio about 1:1.2........... S. noohi ( Wesley, 1943)