Hypocreadium

Bray, Rodney A., Cribb, Thomas H. & Justine, Jean-Lou, 2009, New observations on the genus Hypocreadium Ozaki, 1936 (Digenea: Lepocreadiidae) in the Indo-West Pacific region, including the description of one new species, Zootaxa 2110, pp. 22-40 : 38-39

Key to the species and forms of Hypocreadium

1 Body oval; width less than 70% of length; ovary more or less pretesticular............................................................... 2

- Body closer to circular or wider than long; ovary inter- or post-testicular................................................................. 3

2 Genital pore anterior to intestinal bifurcation; uterus reaches posteriorly to ovary; sucker-ratio 1:1.22 ....................... ...................................................................................................................................... H. symmetrorchis Ozaki, 1936

- Genital pore posterior to intestinal bifurcation; uterus pre-ovarian; sucker-ratio 1:0.51–0.89 ...................................... ..................................................................................................................... H. biminensis ( Sogandares-Bernal, 1959)

3 Anterior notch distinct ................................................................................................................................................ 4

- Anterior notch absent or indistinct ............................................................................................................................... 6

4 Vitelline fields in forebody confluent or nearly so; caecal endings directed distinctly anteriorly ................................. ................................................................................................................................... H. toombo Bray & Justine, 2006

- Vitelline fields distinctly separated in forebody; caecal endings usually directed posteriorly, occasionally transverse or slightly anterior ........................................................................................................................................................ 5

5 Uterus always pre-ovarian; genital pore always at bifurcal level; ovary intertesticular................................................. ....................................................................................................................................... H. cavum Bray & Cribb, 1996

- Uterus may reach para- or post-testicularly; genital pore variable, between pharynx and bifurcal level; ovary inter to post-testicular ............................................................................ H. patellare Yamaguti, 1938 (various forms, see text)

6 Body pyriform.............................................................................................................................................................. 7

- Body oval to circular.................................................................................................................................................... 8

7 Narrow gap between vitelline fields and body margins, fields confluent anteriorly...................................................... ........................................................................................................................ H. lactophrysi ( Nahhas & Cable, 1964)

- Wide gap between vitelline fields and body margins, fields separated anteriorly ............................. H. picasso n. sp.

8 Vitelline fields confluent in forebody .......................................................................................................................... 9

- Vitelline fields separated in forebody ......................................................................................................................... 10

9 Body oval, width 84–91% of length; vitelline fields confluent in hindbody; uterus pre-ovarian .................................. .................................................................................................................................. H. galapagoensis ( Manter, 1945)

- Body probably circular (edges folded); vitelline fields separated in hindbody; uterus para-ovarian ............................ .......................................................................................................................................... H. spinosum ( Manter, 1940)

10 Vitelline fields widely separated in hindbody................................................................................................................. H. lamelliforme ( Linton, 1907) (this species is poorly known and the entry in this key is based on Fig. 77 in Linton (1907) from the grey triggerfish, Balistes capriscus Gmelin (as B. carolinensis Gmelin ) – the first host listed and considered type-host here; fig. 78 represents Dermadena lactophrysi Manter (see Manter, 1945); Fig. 76 also probably represents a Dermadena sp.)

- Vitelline fields confluent in hindbody ........................................................................................................................ 11

11 Caecal ends oriented anteriorly, uterus preovarian.......................................................... H. indicum ( Madhavi, 1972)

- Caecal ends oriented posteriorly, uterus postovarian ................................................................................................. 12

12 Body broadly oval, width, 126–149% of body-length ...................................... H. grandiquamis Bray & Cribb, 1996

- Body more nearly circular, width <114% of body-length .......................................................................................... 13

13 Caecal endings transversely oriented; ovary more or less lobed; eggs 51–56 × 32–44 ................................................. .................................................................................................................................. H. scaphosomum ( Manter, 1940)

- Caecal endings posteriorly oriented; ovary entire; eggs>64 × 40 ............................................................................. 14

14 Vitelline fields confluent in wide band in hindbody............................................................ H. balistes ( Nagaty, 1942)

- Vitelline fields slightly separated in hindbody .................................. H. myohelicatum Bravo-Hollis & Manter, 1957