Bull. Natl. Mus. Nat. Sci., Ser. A, 35(2), pp. 137–155, June 22, 2009

Cryptogonimidae (Trematoda, Digenea) from Fishes ofJapanese and Adjacent Waters
Masaaki Machida
Department of Zoology, National Museum of Nature and Science,
3–23–1 Hyakunincho, Shinjuku-ku, Tokyo, 169–0073 Japan
Meguro Parasitological Museum, 4–1–1 Shimomeguro, Meguro-ku, Tokyo, 153–0064 Japan

Abstract Eighteen species of cryptogonimid digeneans (Trematoda) were obtained from fishesof Japanese and adjacent waters. Two new genera are proposed: Mehravermis gen. nov. for M.
velasquezae sp. nov. and Opistognathotrema gen. nov. for O. philippinense sp. nov. Ten new
species are described: Latuterus karemlal sp. nov. from Lutjanus gibbus (Lutjanidae), Metadena
plectorhinchi sp. nov. from Plectorhinchus gibbosus (Haemulidae), M. pterocaesionis sp. nov. from
Pterocaesio diagramma (Caesionidae), Mehravermis velasquezae sp. nov. from Opistognathus sp.
(Opistognathidae), Opistognathotrema philippinense sp. nov. from Opistognathus sp., Siphoderinaakamachi sp. nov. from Etelis coruscans (Lutjanidae) and Pristipomoides sieboldii (Lutjanidae), S.
marangsi sp. nov. from Lutjanus quinquelineatus, S. nemipteri sp. nov. from Nemipterus virgatus(Nemipteridae), S. ryukyuensis sp. nov. from Lutjanus kasmira and L. quinquelineatus, and S.
xenocephali sp. nov. from Xenocephlus elongatus (Uranoscopidae). Eight previously known
species are recorded: Metadena lutiani (Yamaguti, 1942), M. rooseveltiae (Yamaguti, 1970), M.
sheni Miller et Cribb, 2008, Perlevilobus platycephali (Shen, 1989), Neometadena ovata (Yamaguti, 1952), Siphoderina elongata (Gu et Shen, 1979), S. onaga (Yamaguti, 1970) and S. ulaula(Yamaguti, 1970).
Key words : Digenea, Cryptogonimidae, new genus, new species, marine fish, Japan, Palau,
Philippines, Indonesia.

This paper deals with 18 species of the family
Cryptogonimidae (Trematoda, Digenea) fromfishes of Japanese and adjacent waters. Digeneans obtained were washed in saline, fixed in
AFA under slight pressure, stained with Heidenhain’s hematoxylin and mounted in Canada balsam. The specimens are deposited in the National
Museum of Nature and Science, Tokyo (NSMT)and the Meguro Parasitological Museum (MPM).
Measurements are given in millimeters unlessotherwise indicated.
Latuterus karemlal sp. nov.
(Fig. 1)

Type host. Lutjanus gibbus (Forsskål) (Lutjanidae).
Site. Upper intestine.
Type locality. Palau, western Caroline Is.,

11-VIII-1994.
Specimens. Holotype and 6 paratypes,
NSMT-Pl 4671.
Etymology. The specific name karemlal isfrom the Palauan local name of the host.
Description. Based on seven specimens. Body
oval, 0.87–1.38 long by 0.70–1.16 wide; length/
width ratio 1.1–1.3. Tegument with fine spines.
Oral sucker subterminal, 0.09–0.180.16–0.27,
without circumoral spines; prepharynx 0.04–0.10
long; pharynx well-developed, 0.10–0.130.12–
0.22; esophagus 0.01–0.09 long, bifurcating midway between suckers or closer to acetabulum;
caeca voluminous, arcuate, terminating near posterior end of body. Acetabulum 0.07–0.110.08–
0.14, embedded in ventrogenital sac. Ventrogenital sac surrounded by circular muscle and provided anteriorly with glandular cells. Sucker ratio 1 :0.45–0.51. Forebody 38–45% of body length.

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Testes consisting of nine spherical or ovoid
lobes; in holotype four lobes along right caecum,
partly overlapping it, from postacetabular level tonear posterior end of caecum, three lobes alongleft caecum, and the remaining two lobes situated
one behind another between right and left lobes;
in paratypes nine lobes gather together, without
column, intercaecal, from postacetabular level tolevel of caecal termination. Seminal vesicle tubular, anterior or antero-lateral to acetabulum; pars
prostatica 15–25 m m long. Ventrogenital sac surrounded by circular muscle and provided anteriorly with glandular cells. Genital pore median,on anterior border of acetabulum.
Ovary with ten or so oval lobes, 0.13–0.24
0.21–0.41 as a whole, usually posterior to acetabulum with seminal receptacle in between. Oviductarising from mid-anterior edge of ovary, receiving short duct from seminal receptacle, giving off
Laurer’s canal, then joining vitelline reservoir before entering Mehlis’ gland. Laurer’s canal winding, opening dorsally near posterior border ofacetabulum. Mehlis’ gland submedian, just anterior to ovary. Seminal receptacle saccular, 0.11–
0.200.06–0.13, immediately posterior, posterolateral or occasionally dorsal to acetabulum.
Uterus filling whole body except anterior, central
and posterolateral region, extending posteriorly
almost to end of body, connecting genital atriumby short metraterm. Eggs thin-shelled, 16–18
9–10 m m. Vitelline follicles in available spaceanterior to bifurcal level. Vitelline reservoir
between acetabulum and ovary. Excretory vesicle
Y-shaped; stem broad, bifurcating dorsal to ovary;arms wide, extending to prepharyngeal level; poreterminal.
Remarks. Two other species of Latuterus
have been described from Lutjanus bohar:
Latuterus tkachi Miller et Cribb, 2007 from theGreat Barrier Reef and L. maldivensis Miller et
Cribb, 2007 from Maldives. The present new
species differs from both in that: an esophagus isdistinct, the posterior extent of the testes lies atthe level of the caecal termination, an ovary consists of ten or so lobes, and a uterus almost
reaches the posterior end of the body.

Metadena lutiani (Yamaguti, 1942)(Fig. 2)Siphoderina lutiani Yamaguti, 1942: 375–376, fig. 24.
Pseudosiphoderoides lutiani: Yamaguti 1971: 238.
Metadena lutiani: Miller and Cribb 2008a: 63–64.

Material. Four specimens from the intestineof Lutjanus bohar (Forsskål) (Lutjanidae), Palau,
western Caroline Is., 1-VIII-1980, NSMT-Pl 2395;
and 3 specimens from the intestine of L. bohar,
Koniya, Kagoshima Pref., 3-III-1991, NSMT-Pl
4128.
Description of NSMT-Pl 2395. Body ovoid,
1.67–1.98 long by 1.10–1.28 wide; length/width
ratio 1.4–1.6. Tegument spinose. Dermal glandscattered all over, densely in anterior half ofbody. Oral sucker 0.14–0.190.20–0.22, without
circumoral spines; prepharynx 0.05 long; pharynx 0.11–0.130.12–0.15; esophagus 0.06–0.09
long; caeca passing ventral to testes, terminatingnear middle of posttesticular region. Acetabulum
0.11–0.130.13–0.15, embedded in ventrogenital sac, whose mouth is usually covered withglandular cells. Sucker ratio 1 : 0.65–0.70. Forebody 25–30% of body length. Testes globular or
subglobular, symmetrical, near middle of hindbody; right testis 0.31–0.430.32–0.49; left
testis 0.32–0.420.29–0.54. Posttesticular space
21–30% of body length. Seminal vesicle broad
tubular, almost straight or curved, bipartite, extending posteriorly near anterior border of ovary.
Pars prostatica very small, whose distal end connects metraterm to form short genital atrium.
Genital pore median, on anterior edge of ventrogenital sac. Ovary consisting of a dozen or more
lobes, 0.27–0.340.35–0.40, equatorial or slightly postequatorial. Oviduct arising from central
region of ovary, running forward, receiving shortduct from seminal receptacle near anterior margin of ovary, branching Laurer’s canal at thesame point where the duct from seminal receptacle is received, then turning backward to join
vitelline reservoir, entering Mehlis’ gland. Seminal receptacle saccular, tapering posteriorly, 0.25
0.11–0.15, between acetabulum and ovary. Laurer’s canal opening middorsally near posterior
margin of ovary. Uterus reaching posteriorly toCryptogonimidae from Fishes

139

Fig. 1. Latuterus karemlal sp. nov. Entire worm, ventral view (holotype, NSMT-Pl 4671).
Fig. 2. Metadena lutiani (Yamaguti, 1942). Entire worm, ventral view (NSMT-Pl 2395).

level of caecal termination. Eggs 16–1810–11
m m. Vitelline follicles filling most area fromesophageal level to ovarian level. Excretory vesicle Y-shaped, stem very wide, bifurcating in ovarian zone; arms extending to oral sucker; pore terminal.
Measurements of NSMT-Pl 4128. Body 2.55–
2.83 long by 1.30–1.54 wide; length/width
ratio 1.7–2.1. Oral sucker 0.21–0.230.25–0.30;
prepharynx 0.07–0.10 long; pharynx 0.13–0.15
0.14–0.21; esophagus 0.06–0.07 long; caeca terminating near or slightly beyond middle ofposttesticular space. Acetabulum 0.14–0.21
0.15–0.17. Sucker ratio 1 : 0.55–0.62. Forebody
26–30% of body length. Right testis 0.55–0.65
0.47–0.50; left testis 0.57–0.620.40–0.50.
Ovary 0.32–0.400.42–0.55. Seminal receptacle
0.26–0.340.21–0.27. Eggs 18–219–11 m m.
Remarks. Yamaguti (1942) described thisspecies based on a single macerated specimen
from Lutjanus vaigiensis of Japan; I therefore redescribed the species as above on my non-macerated specimens. My specimens differ somewhat
from the original description. Yamaguti (1942)
stated that his specimen 1.0 long, had an irregularly indented ovary, and an excretory vesicle

branching just behind the intestinal bifurcation.
My specimens are much larger, have a lobed
ovary, and excretory vesicles bifurcating in theovarian zone. Because of his only specimen(MPM Coll. No. 23196) in poor condition, shapeof the ovary and branching position of the excretory vesicle cannot be confirmed. My specimensshow that the distinctive features of Metadena
lutiani are: the body is ovoid; the testes are globular, arranged symmetrically; the ovary is lobate;
and the vitelline follicles fill most area from theesophageal level to the ovarian level.
Metadena rooseveltiae (Yamaguti, 1970)
Pseudosiphoderoides rooseveltiae Yamaguti, 1970: 105,
fig. 147.
Metadena rooseveltiae: Miller and Cribb 2008a: 63–64.

Material. Three specimens from the pyloric
caeca of Pristipomoides argyrogrammicus (Valenciennes) (Lutjanidae), Ishigaki-jima, Okinawa
Pref., 15-III-1975, NSMT-Pl 1372a; 1 specimen
from the pyloric caeca of P. argyrogrammicus,
Nago, Okinawa Pref., 8-VI-1991, NSMT-Pl
4178; and 6 specimens from the pyloric caeca of
P. argyrogrammicus, Palau, western Caroline Is.,

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16-VIII-1994, NSMT-Pl 4694.
Brief description and remarks. Body 2.82–
3.98 long by 1.32–1.78 wide; length/width
ratio 2.0–2.5. Oral sucker 0.19–0.250.23–0.33.
Prepharynx 0.04–0.09 long. Pharynx 0.12–0.21
0.12–0.19. Esophagus 0.10–0.24 long. Acetabulum 0.16–0.230.17–0.27. Sucker ratio 1 : 0.74–
0.96. Forebody 31–38% of body length. A longitudinal series of two or three horizontally elongate slits (0.08–0.12 long) is observed in front of
the acetabulum. Many glandular cells are attached to the slits, whose anterior or posterior
margin is provided with irregular-shaped protuberances. Testes slightly diagonal. Right testis
0.32–0.520.45–0.56; left testis 0.33–0.55
0.35–0.56. Posttesticular space 22–30% of bodylength. Ovary with 2–11 incisions, 0.17–0.29
0.46–0.59. Seminal receptacle 0.26–0.590.12–
0.33. Eggs 19–229–10 m m. This species was
initially described by Yamaguti (1970) from Rooseveltia brighami (Pristipomoides zonatus) of

Hawaii. Yamaguti (1970) stated that “in front of
the acetabulum a longitudinal series of 3–4 (usually 3) transversely elongated cuticular pads,
whose anterior and posterior margins are incised
into 3–5 minute rounded papillae” Actually the“pads” are protuberances on the margins of theslits as described above. The slits seem to be secretory in function.
Metadena sheni Miller et Cribb, 2008
(Figs. 3–4)
Siphoderoides lutiani Shen, 1990: 88–89, fig. 83.
Metadena lutiani (Shen, 1990), preoccupied by M. lutiani(Yamaguti, 1942).
Metadena sheni Miller et Cribb, 2008a: 63–64.

Material. Ten specimens from the pyloric
caeca and upper intestine of Lutjanus vitta (Quoyet Gaimard) (Lutjanidae), Nago, Okinawa Pref.,19-V-1993, NSMT-Pl 4395.
Description. Body fusiform with rounded

Figs. 3–4. Metadena sheni Miller et Cribb, 2008.—3. Entire worm, ventral view (NSMT-Pl 4395). 4. Terminal
genitalia, ventral view. Abbreviations: A, acetabulum; E, egg; G, genital pore; M, metraterm; P, pad; PP, pars
prostatica; S, seminal vesicle; V, ventrogenital sac.

Cryptogonimidae from Fishes

ends, 2.22–3.23 long by 0.91–1.28 wide; length/
width 2.3–3.1. Tegument spinose. Dermal glanddeveloped in anterior half of body and exterior to
testicular region. Oral sucker subterminal, 0.14–
0.210.16–0.26, without circumoral spines.
Prepharyux 0.05–0.15 long. Pharynx 0.08–0.13
0.08–0.14. Esophagus 0.02–0.10 long, bifurcating midway between suckers. Caeca passing almost along interior sides of testes, terminatingnear posterior end of body. Acetabulum 0.09–
0.120.11–0.14, embedded in ventrogenital sac,which is covered anteriorly with bowl-shaped
pad 53–5689–128 m m. The pad surrounded anteriorly by glandular cells. Sucker ratio 1 : 0.44–
0.72. Forebody 21–30% of body length. Testes
longitudinally elongate, diagonal, sometimes anterior edge of fore testis in contact with ovary;right testis 0.55–0.790.32–0.50; left testis 0.48–
0.850.30–0.38. Seminal vesicle swollen, bipartite, almost straight or curved, extending to ovary.
Pars prostatica very small, joining metraterm toform genital atrium. Genital pore median, nearanterior edge of acetabulum. Ovary consisting of
15–30 lobes, 0.27–0.500.42–0.57 as a whole,
39–49% of body length from anterior end.
Oviduct arising from central region of ovary, running forward, receiving short duct from seminal
receptacle, giving off Laurer’s canal at the same
point where the duct from seminal receptacle isreceived, then turning backward, joining vitelline
reservoir, entering Mehlis’ gland. Seminal receptacle saccate, 0.25–0.350.12–0.25, immediately
anterior to ovary. Laurer’s canal opening middorsally near posterior margin of ovary. Uterus extending near posterior end of body. Metraterm
very short. Eggs 17–1910–11 m m. Vitelline
follicles predominantly exterior and dorsal tocaeca, extending from midway between intestinal
bifurcation and acetabulum or nearer acetabulum
to anterior edge of posterior testis. Excretory
vesicle Y-shaped, bifurcating near level of posterior border of ovary; arms extending nearprepharynx or oral sucker; pore terminal.
Remarks. This species resembles the abovementioned Metadena lutiani, but differs from itby having a fusiform body; testes longitudinally141

elongate, extracaecal, arranged diagonally; andvitelline follicles predominantly lying dorsal andexterior to caeca, not extending inward. Shen
(1990) initially described this species from Lutjanus erythopterus of Hainan Island, China. His
description was somewhat insufficient; I therefore redescribe it based on my specimens.
Metadena plectorhinchi sp. nov.
(Figs. 5–6)

Type host. Plectorhinchus gibbosus (Lacepède)(Haemulidae).
Site. Intestine.
Type locality. Nago, Okinawa Pref., 2-XII1996.
Specimens. Holotype and 19 paratypes,
NSMT-Pl 4993.
Etymology. The specific name plectorhinchi
is derived from the generic name of the host.
Description. Based on 20 specimens. Body
oval, 0.99–1.57 long by 0.53–0.79 wide; length/
width ratio 1.6–2.2. Tegument spinose. Dermal
gland developed in forebody. Oral sucker
71–107122–166 m m; prepharynx 25–64 m mlong; pharynx subglobular, 89–12287–115 m m;esophagus short, 25–64 m m long, bifurcatingnear anterior end of middle third of forebody;
caeca relatively wide, passing ventral to testes,
terminating near posterior end of body. Acetabulum 64–9266–89 m m, embedded in shallow
ventrogenital sac. Forebody 53–62% of bodylength. Sucker ratio 1 : 0.48–0.62. In front of theacetabulum is a longitudinal series of three small
glandular pits, whose orifice is 10–25 m m wide.
Anteriormost pid at a distance of 92–192 m mfrom anterior edge of acetabulum.
Testes spherical to ovoid, symmetrical, a shortdistance posterior to acetabulum; right testis
0.15–0.210.12–0.19; left testis 0.12–0.22
0.13–0.21. Posttesticular space 15–32% of bodylength. Seminal vesicle tubular, largely preacetabular, beginning from acetabular level, firstrunning forward, straight, swollen, then turning
backward, gradually slender, highly convoluted,
finally uniting pars prostatica 25–5032–52 m m.

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Masaaki Machida

Genital pore median, on anterior edge of ventrogenital sac.
Ovary median, 4–8 lobes, 0.11–0.230.18–
0.29, partly overlapping testes ventrally. Oviductarising from near center of ovary, giving off Laurer’s canal just before connecting seminal receptacle, joining vitelline reservoir, entering Mehlis’
gland. Laurer’s canal opening dorsally near midanterior border of ovary. Seminal receptacle 65–14860–115 m m, immediately anterodextral toacetabulum. Uterus filling available space ofhindbody, then passing sinistral to acetabulum,
joining genital atrium by short metraterm
15–18 m m long. Eggs thick-shelled, 19–2310–12 m m. Vitelline follicles rather ramified, between some distance posterior to intestinal bifurcation and postacetabular level. Excretory vesicle
Y-shaped, bifurcating in ovarian zone to form
arms extending to near oral sucker; pore terminal.

Remarks. This species differs from all othersin Metadena by having an acetabulum consistently posterior to the midbody, and a midventral longitudinal row of three small glandular pits infront of the acetabulum.
Metadena pterocaesionis sp. nov.
(Figs. 7–8)

Type host. Pterocaesio diagramma (Bleeker)(Caesionidae).
Site. Pyloric caeca and upper intestine.
Type locality. Nago, Okinawa Pref., 26-XI1996.
Other locality. Koniya, Kagoshima Pref., 20XI-1989.
Specimens. Holotype and 5 paratypes, NSMTPl 4964; 1 paratype, NSMT-Pl 3806.
Etymology. The specific name pterocaesionis
is derived from the generic name of the host.

Figs. 5–6. Metadena plectorhinchi sp. nov. —5. Entire worm, ventral view (holotype, NSMT-Pl 4993). 6. Terminal genitalia, ventral view.
Figs. 7–8. Metadena pterocaesionis sp. nov. —7. Entire worm, ventral view (holotype, NSMT-Pl 4964). 8. Terminal genitalia, ventral view. Abbreviations: A, acetabulum; E, mouth of embedded acetabulum; G, genital
pore; GP, glandular pit; M, metraterm; P, pad; PP, pars prostatica; S, seminal vesicle; V, ventrogenital sac.

Cryptogonimidae from Fishes

Description. Based on seven specimens.
Body elongate, 4.19–5.65 long by 0.78–1.14
wide; length/width ratio 4.4–5.8. Tegument withfine spines. Dermal gland scattered all over. Oral
sucker 0.20–0.240.29–0.33, without circumoral
spines; prepharynx 0.05–0.10 long; pharynx
0.11–0.150.11–0.14; esophagus 0.07–0.15 long,bifurcating midway between suckers; caeca narrow, passing ventral to testes, terminating near
middle of posttesticular space. Acetabulum
0.09–0.130.10–0.16, embedded in ventrogenital sac. Sucker ratio 1 : 0.36–0.49. Forebody
15–19% of body length.
Testes globular, diagonal in middle of posterior half of body; right testis 0.19–0.500.32–
0.66; left testis 0.25–0.490.33–0.68. It is not
fixed which side of testis is anterior. Posttesticular space 15–24% of body length. Seminal vesicle long slender, slightly winding, maybe bipartite, beginning from some distance anterior toovary; pars prostatica 50–6422–33 m m; uniting
metraterm to form short genital atrium. Mouth ofembedded acetabulum provided anteriorly withsmall pad. The pad enclosed anteriorly by glandular cells. Genital pore opening dorsal to thepad.
Ovary with 13–20 lobes, 0.29–0.460.34–
0.60 as a whole, median, equatorial. Oviductarising from center of ovary, running anterodiagonally, receiving short duct from seminal receptacle, giving off Laurer’s canal at the same point
where the duct from seminal receptacle is received, turning posterodiagonally, joining
vitelline reservoir, then entering Mehlis’ gland.
Seminal receptacle saccular, 0.12–0.560.06–
0.30, posterodorsal to ovary. Laurer’s canal opening middorsally near posterior margin of ovary.
Uterine coils descending to near posterior end ofbody, then ascending, passing ventral to seminal
vesicle. Eggs 17–209–10 m m. Vitellaria consisting of 7–10 bunches of follicles on each side,sometimes partly confluent, extending from alevel between acetabulum and ovary to a level
between ovary and anterior testis. Excretory vesicle Y-shaped, bifurcating posterior to ovary; arms
reaching pharyngeal or prepharyngeal level; pore143

terminal.
Remarks. Oshmarin et al. (1961) described
Disacanthus longus as a new genus and species
from Pristipomoides thypus (typus?) (Lutjanidae)
in the Gulf of Tonkin. Yamaguti (1971) reduced
Disacanthus to a junior synonym of Pseudosiphoderoides and transferred D. longus to
the genus Pseudosiphoderoides as P. longus.
Miller and Cribb (2008a) proposed Pseudosiphoderoides to a junior synonym of Metadena and placed P. longus in Metadena as M.
longa. Yamaguti (1970) described Pseudosiphoderoides opakapaka (now Metadena
opakapaka) from Pristipomoides microlepis of
Hawaii. He did not compare his species with M.
longa. Both species are from fishes of Pristipomoides and there is no significant difference between the two. I consider M. opakapaka synonymous with M. longa. M. longa is the only one in
Metadena to possess an elongate body. The present new species is the second with an elongate
body, but differs from M. longa in having a moreanterior acetabulum, longer distance between theacetabulum and ovary, caeca passing ventral to
the testes, a seminal receptacle dorsoposterior tothe ovary, the anterior extent of the vitelline follicles lying midway between the acetabulum andovary, and smaller eggs.
Perlevilobus platycephali (Shen, 1989)
Paraisocoelium platycephali Shen, 1989: 153–154, fig. 1.
Perlevilobus platycephali: Miller and Cribb 2008a: 67.

Material. Three specimens from the pyloric
caeca of Inegocia guttata (Cuvier) (Platycephalidae), Palawan, the Philippines, 12-XI-1988,
NSMT-Pl 3564.
Measurements and remarks. Body 2.64–
3.79 long by 0.45–0.53 wide; length/width ratio
5.5–8.3. Oral sucker 0.14–0.150.13–0.16;
prepharynx 0.03–0.05 long; pharynx 0.05–
0.060.06–0.07; esophagus 0.19–0.32 long.
Acetabulum 0.07–0.090.10. Sucker ratio
1 : 0.65–0.77. Forebody 36–40% of body length.
Anterior testis 0.18–0.310.24–0.26; posterior
testis 0.23–0.350.22–0.27. Posttesticular space

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22–30% of body length. Ovary 0.16–0.20
0.21–0.22. Seminal receptacle 0.10–0.140.16–
0.24. Eggs 16–199–10 m m. This species was
originally described by Shen (1989) from Platycephalus indicus (Platycephalidae) in Jiaozhou
Bay, China. My specimens agree fairly well withthe original description. They have an ovoid tofunnel-shaped oral sucker, and a slightly lobed to
distinctly trilobed ovary. The anterior extent of
the vitelline follicles lies between the intestinal
bifurcation and acetabulum.
Genus Mehravermis nov.
Diagnosis. Body linguiform, spinose. Dermal gland densely developed in forebody. Eyespot pigment present. Oral sucker subterminal,
without circumoral spines. Prepharynx relatively
short. Pharynx moderately developed. Esophagus
short. Caeca reaching near posterior extremity.
Acetabulum smaller than oral sucker, a little anterior to midbody. Testes globular, smooth, diagonal, partly overlapping caeca, anterior to middleof hindbody. Seminal vesicle long, tubular, convoluted anterior to acetabulum; pars prostatica
distinct. Distal end of pars prostatica uniting metraterm to form short genital atrium. Genital pore
median, near anterior edge of acetabulum. Ovary
acinous, almost midbody, partly overlapping anterior testis. Egg without filament. Seminal receptacle saccate, between acetabulum and ovary.
Laurer’s canal opening dorsally in ovarian zone.
Uterus extending to near posterior end of body.
Vitelline follicles almost confluent, extending
from near intestinal bifurcation to posterior
testis. Excretory vesicle Y-shaped, arms reachingnear intestinal bifurcation. Parasitic in marine
teleosts.
Type and only species: Mehravermis velasquezae sp. nov.
Remarks. Mehravermis closely resembles
Mehrailla Srivastava 1939, but differs from it byhaving globular testes arranged diagonally, aseminal vesicle largely anterior to the acetabulum, vitelline follicles that extend from near theintestinal bifurcation to the posterior margin of
the rear testis, and eggs without a filament.
Mehrailla is found in a stromateid fish off India,
whereas Mehravermis occurs in an opistognathid
off the Philippines.
Mehravermis velasquezae sp. nov.
(Figs. 9–10)

Type host. Opistognathus sp. (Opistognathidae).
Site. Intestine.
Type locality. Palawan, the Philippines, 12XI-1988.
Specimens. Holotype and 9 paratypes, NSMTPl 3558a.
Etymology. The name Mehravermis indicatesthe close relationship of this genus with Mehrailla
Srivastava, 1939, and velasquezae is named inhonor of the late Prof. Carmen C. Velasquez inrecognition of her contributions to the field of
trematodology.
Description. Based on 10 specimens. Body
linguiform, rounded anteriorly, tapering posteriorly, 1.95–3.25 long by 0.95–1.23 wide; length/
width ratio 2.1–2.8. Tegument spinose. Dermal
gland densely developed in forebody. Eyespot
pigment present. Oral sucker subterminal, rounded, 0.20–0.280.27–0.32, without spines; prepharynx 0.03–0.13 long; pharynx 0.08–0.120.13–
0.22; esophagus short, 0.01–0.08 long, bifurcating nearer oral sucker than acetabulum; caecawide, reaching near posterior end of body. Acetabulum small, 0.09–0.110.10–0.13, embedded in weakly developed ventrogenital sac. Sucker ratio 1 : 0.36–0.42. Forebody 35–44% of bodylength.
Testes globular, diagonal, anterior to midlineof hindbody; right testis usually posterior to left
testis, 0.20–0.330.30–0.36; left testis 0.23–
0.300.24–0.34. Posttesticular space 25–38% ofbody length. Seminal vesicle tubular, long, extending from near or well into acetabular level to
midway between intestinal bifurcation and acetabulum; largely preacetabular; sinuous; connecting pars prostatica 0.07–0.180.07–0.18,

Cryptogonimidae from Fishes

immediately anterior to acetabulum. Distal endof pars prostatica joining metraterm to form
short genital atrium. Genital pore median, nearanterior edge of acetabulum.
Ovary acinous, 0.16–0.330.44–0.55, a shortdistance posterior to acetabulum, partly overlapping anterior testis. Oviduct arising from centerof ovary, running forward, giving off Laurer’s
canal just before uniting short duct from seminal
receptacle, turning backward, joining vitelline
reservoir, entering Mehlis’ gland. Seminal receptacle saccular, 0.12–0.180.15–0.21, between
acetabulum and ovary. Laurer’s canal short,curved, opening dorsally near center of ovary.
Uterus forming transverse coils, reaching nearposterior end of body, then running forward dextral or sinistral to ovary. Metraterm very short.
Eggs 21–2312–13 m m. Vitellaria ramiform,
almost confluent from midway between intestinal
bifurcation and acetabulum to posterior marginof rear testis. Excretory vesicle Y-shaped; arms
reaching near intestinal bifurcation; pore terminal.
Remarks. This species closely resembles
Mehrailla ovocaudatum Srivastava, 1939 (typeand only species of the genus), but differs from itby having round testes that are diagonal, a seminal vesicle largely anterior to the acetabulum,
vitelline follicles intruding to the median line,
and eggs without a filament.
Genus Opistognathotrema nov.
Diagnosis. Body linguiform, spinose. Dermal gland developed in anterior half of body.
Eyespot pigment present. Oral sucker large; orifice surrounded by sphincter latero-posteriorly.
Prepharynx short. Pharynx well-developed.
Esophagus short. Caeca passing outside of testes,
opening through separate ani near posterior endof body. Acetabulum smaller than oral sucker, atanterior 1/3 of body length. Testes globular, diagonal, almost middle of hindbody. Seminal vesicle
tubular, bipartite, largely in acetabular zone. Pars
prostatica distinct, immediately anterior to acetabulum. Distal end of pars prostatica joining

145

metraterm to form short genital atrium. Genital
pore median, near anterior edge of acetabulum.
Ovary acinous, near midbody. Uterus extending
from acetabulum to posterior end of body. Seminal receptacle saccate, between acetabulum andovary. Laurer’s canal opening near center ofovary. Vitelline follicles extending along caecafrom midway between acetabulum and ovary to
middle of posttesticular space. Excretory vesicle
Y-shaped, arms reaching near intestinal bifurcation. Parasitic in marine teleosts.
Type and only species: Opistognathotrema
philippinense sp. nov.
Remarks. Opistognathotrema differs fromclosely related Mehravermis by possessing anoral sucker with sphincter, caeca opening throughseparate ani at the posterior end of the body, aseminal vesicle largely lateral or dorsal to the acetabulum, and vitelline follicles in lateral fields
extending from a level midway between the acetabulum and ovary to the midlevel of theposttesticular space.
Opistognathotrema philippinense sp. nov.
(Figs. 11–12)

Type host. Opistognathus sp. (Opistognathidae).
Site. Intestine and rectum.
Type locality. Palawan, the Philippines, 12XI-1988 and 22-VIII-1990.
Specimens. Holotype, NSMT-Pl 3558b and 9paratypes, NSMT-Pl 3558b and 3960.
Etymology. The name Opistognathotrema isderived from the generic name of the host, andphilippinense indicates the type locality.
Description. Based on 10 specimens. Body
linguiform with rounded ends, 1.87–2.95 longby 0.80–1.05 wide; length/width ratio 2.2–2.8.
Tegument spinose. Dermal gland developed inanterior half of body. Eyespot pigment present.
Oral sucker subterminal, 0.27–0.350.33–0.44,
orifice surrounded by well-developed sphincter
latero-posteriorly. Prepharynx 0.03–0.10 long;pharynx 0.10–0.150.14–0.21; esophagus short,
up to 0.06 long; caeca broad, passing outsides of146

Masaaki MachidaFigs. 9–10. Mehravermis velasquezae gen. et sp. nov. — 9. Entire worm, ventral view (holotype, NSMT-Pl
3558a). 10. Terminal genitalia, ventral view.
Figs. 11–12. Opistognathotrema philippinense gen. et sp. nov. — 11. Entire worm, ventral view (holotype,
NSMT-Pl 3558b). 12. Terminal genitalia, ventral view. Abbreviations: A, acetabulum; G, genital pore; M,
metraterm; P, pars prostatica; S, seminal vesicle; U, uterus.

testes, opening through separate ani at posterior
end of body. Acetabulum 0.14–0.190.16–0.21,
embedded in weakly developed ventrogenital sac.
Sucker ratio 1 : 0.41–0.52. Forebody 28–39% of
body length.
Testes globular, diagonal; right testis usuallybehind left one, 0.16–0.320.18–0.33; left testis
0.15–0.280.17–0.31. Posttesticular space 28–
35% of body length. Seminal vesicle tubular, usually constricted into two portions, beginning frompostacetabular level, passing lateral or dorsal toacetabulum, then connecting saccate pars prostatica 55–9030–50 m m, which lies in front ofacetabulum. Distal end of pars prostatica joining
metraterm to form short genital atrium. Genital
pore median, near anterior edge of acetabulum.
Ovary acinous, 0.17–0.290.30–0.46, near
midbody, attached to or partly overlapping anterior testis. Oviduct arising from center of ovary,running forward, joining short duct from seminal
receptacle, giving off Laurer’s canal, turning
backward, uniting vitelline reservoir, entering
Mehlis’ gland. Seminal receptacle saccular, 0.12–
0.290.09–0.20, between acetabulum and ovary.
Laurer’s canal slightly curved, opening dorsallynear center of ovary. Uterus descending between
testes, reaching near posterior end of body, thenascending between testes again, ventral to ovary
and seminal receptacle, finally lateral to acetabulum. Metraterm up to 40 m m long. Eggs 19–2211–12 m m. Vitelline follicles extending along
caeca from about midway between acetabulum
and ovary to middle of posttesticular space. Excretory vesicle Y-shaped; arms extending to nearintestinal bifurcation; pore terminal.
Remarks. This species was found with theabove-mentioned Mehravermis velasquezae froman unidentified Opistognathus species. It differs

Cryptogonimidae from Fishes

from the related M. velasquezae by possessing
an oral sucker with sphincter, caeca opening
through separate ani at the posterior end of thebody, an acetabulum lying a short distance posterior to the intestinal bifurcation, a seminal vesiclelargely lateral or dorsal to the acetabulum, andvitelline follicles extending into the lateral fields
from a level midway between the acetabulum andovary to the midlevel of the posttesticular space.
Neometadena ovata (Yamaguti, 1952)
Paracryptogonimus ovatus Yamaguti, 1952: 173–175, fig. 4.
Neoparacryptogonimus ovatus: Hafeezullah 1975: 54.
Neometadena ovata: Miller and Cribb 2008a: 65–66.

Material. One specimen from the intestine of
Lutjanus monostigma (Cuvier) (Lutjanidae),
Palawan, the Philippines, 8-XI-1988, NSMT-Pl
3539; 1 specimen from the intestine of L. argentimaculatus (Forsskål), Palawan, 11-XI-1988,
NSMT-Pl 3554; and 8 specimens from the intestine of L. argentimaculatus, Palawan, 12-XI1988, NSMT-Pl 3561.
Measurements. Body 1.52–2.63 long by 1.02–
1.55 wide; length/width ratio 1.5–1.8. Oral sucker 0.17–0.240.23–0.36 with 64–83 circumoral
spines. Circumoral spines 14–16 m m long. Pharynx 0.14–0.210.16–0.28. Acetabulum 0.19–
0.280.20–0.30. Sucker ratio 1 : 0.80–1.10. Forebody 24–33% of body length. Right testis 0.23–
0.400.16–0.36; left testis 0.17–0.370.17–
0.34. Posttesticular space 25–36% of bodylength. Ovary 0.13–0.260.37–0.55. Eggs 16–
199–10 m m. This species was originally described by Yamaguti (1952) from an unknown
marine fish of Macassar (=Ujung Pandang), Indonesia.
Siphoderina elongata (Gu et Shen, 1979)(Fig. 13)
Paracryptogonimus elongatus Gu et Shen, 1979: 347–
348, fig. 6.
Siphoderina elongata: Miller and Cribb 2008a: 68–69.

Material. Five Specimens from the intestineof Nemipterus sp. (Nemipteridae), Palawan, the147

Fig. 13. Siphoderina elongata (Gu et Shen,
1979). Posterior end of body, showing ani oneither side of excretory pore, ventral view
(NSMT-Pl 5187). Abbreviations: A, anus; E,
excretory pore; U, uterus.

Philippines, 8-XI-1988, NSMT-Pl 3535; 4 specimens from the pyloric caeca of Nemipterus sp.,
Lombok, Indonesia, 20-I-1994, NSMT-Pl 5174;
and 1 specimen from the pyloric caeca of Nemipterus sp., Lombok, 23-I-1994, NSMT-Pl 5187.
Brief description of NSMT-Pl 3535. Body
2.77–3.17 long by 0.55–0.66 wide; length/width
ratio 4.4–5.8. Tegument spinose. Eyespot pigment present. Oral sucker 0.17–0.210.22–0.24,
with 25–27 circumoral spines. Prepharynx 0.06–
0.14 long. Pharynx 0.10–0.110.10–0.13. Esophagus 0.02–0.09 long. Caeca passing exterior totestes, opening through separate ani near posterior end of body. Acetabulum 0.10–0.120.11–
0.13, embedded in ventrogenital sac. Mouth ofventrogenital sac provided with semicircular padanteriorly. Glandular cells attached to the pad.
Sucker ratio 1 : 0.48–0.53. Forebody 20–24% ofbody length. Right testis 0.33–0.400.15–0.21;
left testis 0.33–0.390.15–0.20. Posttesticularspace 15–17% of body length. Seminal vesicle
tubular, bipartite. Ovary 0.22–0.290.25–0.33,
41–46% of body length from anterior end. Seminal receptacle 0.22–0.300.13–0.16, anterior toovary. Eggs 16–1810–11 m m.
Measurements of NSMT-Pl 5174 and 5187.
Body 3.45–5.49 long by 0.72–1.03 wide; length/
width ratio 4.4–5.4. Oral sucker 0.21–0.26
0.19–0.24, with prominent 25–27 circumoral
spines. Prepharynx up to 75 m m long. Pharynx
0.08–0.130.09–0.10. Esophagus 0.02–0.09 long.
Acetabulum 0.12–0.150.13–0.16, embedded in
ventrogenital sac. Sucker ratio 1 : 0.60–0.71.

148

Masaaki Machida

Forebody 12–17% of body length. Right testis
0.56–0.900.32–0.40; left testis 0.52–0.70
0.30–0.39, anterior to right testis. Posttesticularspace 17–22% of body length. Ovary 0.28–
0.350.56–0.75, 32–41% of body length fromanterior end. Seminal receptacle 0.24–0.58
0.13–0.43. Eggs 17–199–10 m m.
Remarks. Gu and Shen (1979) originally described this species from Nemipterus virgatus ofHainan Island, China. My specimens were foundfrom the same genus of host, but somewhat differ
from the original description. They have a larger
sucker ratio, the posterior extent of the vitelline
follicles lying between the level of anterior andmiddle of the fore testis, and caeca opening
through separate ani near the posterior end of the
body. Gu and Shen (1979) did not mention ani intheir description. The presence of ani is a distinctive feature of this species.
Siphoderina onaga (Yamaguti, 1970)
Paracryptogonimus onaga Yamaguti, 1970: 102–103, fig.
143.
Siphoderina onaga: Miller and Cribb 2008a: 68–69.

Material. Two specimens from the pyloric
caeca of Etelis coruscans Valenciennes (Lutjanidae), Nago, Okinawa Pref., 9-VI-1988,
NSMT-Pl 3448.
Brief description and remarks. Body 11.2–
12.5 long by 3.55–3.65 wide; length/width ratio
3.2–3.4. Dermal glands developed in anterior
part of body. Oral sucker 0.37–0.490.49–0.52,
with 49 circumoral spines; prepharynx 0.12–0.24
long; pharynx 0.18–0.210.22–0.23; esophagus
0.40–0.55 long, bifurcating midway between
pharynx and acetabulum; caeca passing alongouter margins of testes, ending a short distancefrom posterior end of body. Acetabulum 0.39–
0.450.44–0.48. Sucker ratio 1 : 0.90–0.91.
Forebody 19–22% of body length. Testes elliptical, with lateral depressions, situated diagonallyin middle of hindbody; right testis anterior,
2.18–2.630.78–0.88; left testis 2.45–2.83
0.75–0.95. Posttesticular space 20–24% of bodylength. Ovary acinous, 0.84–0.970.92–1.14,

38–41% of body length from anterior end of
body. Seminal receptacle 1.03–1.180.50–0.63.
Eggs 21–268–10 m m. Vitellaria consisting ofseveral rosette-shaped clusters, extending along
caeca from a short distance posterior to acetabulum to anterior border of front testis. Excretoryarms reaching near posterior margin of oral sucker. This species was initially described by Yamaguti (1970) from Etelis carbunculus of Hawaii.
His specimens were 2.2 to 6.9 long by 0.9 to 2.0
wide. With the exception of being considerablylarger worms with correspondingly larger organs,
my specimens agree well with the original description such as the number of circumoral
spines, an acetabulum slightly smaller than theoral sucker, elongate testes, the distribution ofvitellaria, egg size, etc.
Siphoderina ulaula (Yamaguti, 1970)
Paracryptogonimus ulaula Yamaguti, 1970: 103, fig. 144.
Siphoderina ulaula: Miller and Cribb 2008a: 68–69.

Material. Six specimens from the pyloric
caeca of Pristipomoides argyrogrammicus (Valenciennes) (Lutjanidae), Nago, Okinawa Pref.,8-VI-1991, NSMT-Pl 4178; and 7 specimensfrom the pyloric caeca of P. argyrogrammicus,
Nago, 5-X-1994, NSMT-Pl 4740.
Measurements. Body 3.40–5.25 long by
1.65–2.30 wide; length/width ratio 1.9–2.8. Oral
sucker 0.11–0.240.18–0.36, with 44–57 circumoral spines. Prepharyx 0.04–0.13 long. Pharynx
0.10–0.130.11–0.18. Esophagus 0.11–0.27 long.
Acetabulum 0.15–0.210.18–0.26. Sucker ratio
1 : 0.56–1.16. Forebody 19–25% of body length.
Right testis 0.64–0.840.53–0.70. Left testis
0.65–0.990.53–0.75. Posttesticular space 30–
40% of body length. Ovary 0.41–0.620.65–
0.88. Eggs 20–2410–12 m m. This species was
initially described by Yamaguti (1970) from
Etelis marshi (Lutjanidae) of Hawaii.
Siphoderina akamachi sp. nov.
(Fig. 14)Type host.

Etelis coruscans Valenciennes

Cryptogonimidae from Fishes(Lutjanidae).
Other host. Pristipomoides sieboldii (Bleeker) (Lutjanidae).
Site. Pyloric caeca and upper intestine.
Type locality. Koniya, Kagoshima Pref., 8III-1991.
Other locality. Nago, Okinawa Pref., 7-XII1995; 29-XI-1996.
Specimens. Holotype and 6 paratypes, NSMTPl 4153; 5 paratypes, NSMT-Pl 4804; 3 paratypes,
NSMT-Pl 4983.
Etymology. The specific name akamachi isfrom the Japanese local name of the host.
Description. Based on 15 specimens. Body
elongate, 3.75–5.70 long by 1.03–1.40 wide, broad
anteriorly and almost rounded posteriorly;
length/width ratio 3.4–4.9. Tegument thick, withfine spines. Dermal glands developed all over.
Cephalic glands gathering around oral sucker andmidway between suckers. Oral sucker 0.15–
0.270.26–0.41, with 62–68 circumoral spines;

Fig. 14. Siphoderina akamachi sp. nov. Entire
worm, ventral view (holotype, NSMT-Pl4153).

149

prepharynx 0.03–0.15 long; pharynx 0.13–0.17
0.12–0.17; esophagus 0.07–0.15 long, bifurcating midway between pharynx and acetabulum;
caeca narrow, passing ventral to testes, terminating a short distance from posterior end of body.
Acetabulum 0.13–0.180.13–0.19, embedded in
ventrogenital sac. Ventrogenital sac surroundedby glandular cells. Forebody 17–24% of bodylength. Sucker ratio 1 : 0.40–0.58.
Testes with shallow and deep incisions, usuallywider than long, tandem, slightly separated; anterior testis 0.36–0.670.79–1.14; posterior testis
0.44–0.680.71–1.00. Posttesticular space 19–
32% of body length. Seminal vesicle a wide sinuous tube, indistinctly bi- or tri-partite, extending
from anterior edge of ovary to a short distanceposterior to acetabulum; pars prostatica 25–50
m m long, near posterior border of acetabulum.
Genital pore immediately in front of acetabulum.
Ovary acinous, 0.34–0.600.54–0.75, preequatorial. Oviduct arising from center of ovary,
ascending, uniting duct from seminal receptacle,
dividing Laurer’s canal, turning backward, receiving vitelline reservoir, entering Mehlis’
gland. Seminal receptacle 0.35–0.680.15–0.29,
tapering posteriorly to connect oviduct, immediately anterior to ovary, in contact with posterior
portion of seminal vesicle. Laurer’s canal long,descending, opening mid-dorsally near posteriorborder of ovary. Uterus reaching near posterior
end of body, then ascending laterad to ovary andventrad to seminal vesicle; metraterm 50 m m long.
Eggs thin-shelled, 18–218–10 m m. Vitelline follicles partly rosette-shaped, largely in extracaecal
fields, from acetabular level to near anterior margin of fore testis. Excretory vesicle Y-shaped, bifurcating just posterior to ovary; arms reachingsides of oral sucker or prepharynx; pore terminal.
Remarks. Velasquez(1961)
described
Pseudallacanthochasmus grandispinus as a new
genus and species from an unidentified species ofLutjanus off the Philippines. Miller and Cribb(2008b) reduced Pseudallacanthochasmus to ajunior synonym of Siphoderina and P. grandispinus was placed in Siphoderina as S. grandispinus.
The present new species is most similar to S.

150

Masaaki Machida

grandispinus, but differs from it by having anoral sucker with 62 to 68 circumoral spines,
transversely elongate testes with incisions, anacinous ovary, vitelline follicles extending in thelateral fields from the acetabular level to the anterior margin of the fore testis, and larger eggs.
Siphoderina marangsi sp. nov.
(Figs. 15–16)

Type host. Lutjanus quinquelineatus (Bloch)(Lutjanidae).
Site. Pyloric caeca.
Type locality. Palawan, the Philippines, 17XI-1988.
Specimens. Holotype and 14 paratypes,
NSMT-Pl 3600.
Etymology. The specific name marangsi isfrom the Philippine local name of the host.
Description. Based on 15 specimens. Body
oval, 0.80–1.17 long by 0.47–0.82 wide; length/
width ratio 1.2–1.8. Tegument with fine spines.
Dermal gland sparsely scattered in forebody.
Eyespot pigment dispersed near pharyngeal level.
Oral sucker usually cup-shaped, 0.11–0.19

0.15–0.23, with 23–28 circumoral spines. Circumoral spines prominent, slender, 33–397–9 m m.
Prepharynx 0.02–0.08 long; pharynx globular,
0.05–0.070.06–0.11; esophagus 0.02–0.10 long,bifurcating midway between pharynx and acetabulum; caeca passing ventral to testes, terminatingnear posterior end of body. Acetabulum 0.04–
0.080.05–0.08, embedded in ventrogenital sac.
Sucker ratio 1 : 0.31–0.47. Forebody 32–42% ofbody length.
Testes almost ovoid, symmetrical, near middleof hindbody; right testis 0.20–0.350.14–0.31;
left testis 0.20–0.330.13–0.31. Posttesticularspace 14–25% of body length. Seminal vesicle
tubular, convoluted, extending from ovarian to bifurcal level. At a short distance anterior to acetabulum, distal end of seminal vesicle uniting
small bulbous pars prostatica 37–5025–40 m m,which joins metraterm to form short genital atrium. Ventrogenital sac provided anteriorly withseed leaf-like pad. Genital pore median, near anterior edge of acetabulum.
Ovary with 5–8 lobes, 0.10–0.230.14–0.32,
median, between anterior portions of testes.
Oviduct arising from center of ovary, running

Figs. 15–16. Siphoderina marangsi sp. nov. — 15. Entire worm, dorsal view (holotype, NSMT-Pl 3600). 16.
Terminal genitalia, ventral view. Abbreviations: A, acetabulum; G, genital pore; M, metraterm; P, pad; PP,pars prostatica; S, seminal vesicle; U, uterus.

Cryptogonimidae from Fishes

forward to receive duct from seminal receptacle,
then backward, giving off Laurer’s canal, receiving vitelline reservoir, entering Mehlis’ gland.
Seminal receptacle subglobular, 0.07–0.170.05–
0.13, submedian, between acetabulum and ovary.
Laurer’s canal opening middorsally at mid- to
postovarian level. Uterus filling most of available
space of hindbody; metraterm 15–20 m m long.
Vitelline follicles in lateral fields, extending frompharyngeal to preovarian level. Eggs 16–198–
10 m m. Excretory vesicle Y-shaped, bifurcatingnear postovarian level; broad arms extending tonear prepharyngeal level; pore terminal.
Remarks. The present new species is distinguishable from all others in Siphoderina by combination of the oval body, the oral sucker withprominent 23 to 28 circumoral spines, the ovary
consisting of five to eight lobes, and the vitelline
follicles in the lateral fields, extending from thepharyngeal level to the preovarian level.

151

Siphoderina nemipteri sp. nov.
(Figs. 17–18)

Type host. Nemipterus virgatus (Houttuyn)(Nemipteridae).
Site. Intestine.
Type locality Owase, Mie Pref., 16-X-1986.
Specimens. Holotype and 9 paratypes,
NSMT-Pl 3299.
Etymology. The specific name nemipteri isderived from the generic name of the host.
Description. Based on 10 specimens. Body
elongate, 2.08–4.00 long by 0.59–1.08 wide;
length/width ratio 3.4–4.9. Tegument with finespines. Dermal gland densely developed in forebody. Eyespots at prepharyngeal-pharyngeal
level. Oral sucker cup- or barrel-shaped, retractable, 0.14–0.240.15–0.23. Circumoral
spines indistinct, maybe 28–35 in number.
Cephalic glands converging at the base of oral
sucker; their ducts extending anteriorly, opening

Figs. 17–18. Siphoderina nemipteri sp. nov. — 17. Entire worm, ventral view (holotype, NSMT-Pl 3299). 18.
Terminal genitalia, ventral view. Abbreviations: A, acetabulum; F, transversal fiber; G, genital pore; P, pad; V,mouth of ventrogenital sac.

152

Masaaki Machida

between circumoral spines. Prepharynx up to
0.11 long. Pharynx 0.05–0.110.05–0.10. Esophagus 0.05–0.15 long. Intestinal bifurcation midway between suckers. Caeca narrow, passing ventral to testes, ending near middle of posttesticularspase. Acetabulum 0.11–0.170.12–0.20, embedded in ventrogenital sac. Ventrogenital sac
with semicircular pad anteriorly and thick walllatero-posteriorly. The pad provided anteriorly
with glandular cells. The wall 0.03–0.12 thick inlateral side, enclosed by glandular cells and connecting lateral body margin by transversal fibers.
Sucker ratio 1 : 0.81–0.95. Forebody 20–27% ofbody length.
Testes subglobular, diagonal or occasionallytandem; anterior testis 0.27–0.650.30–0.71,
posterior testis 0.30–0.900.38–0.70, in middleof hindbody. Posttesticular space 18–29% of
body length. Seminal vesicle tubular, convoluted,
extending posteriorly near ovary; distal end of
seminal vesicle uniting small pars prostatica
which joins metraterm to form short genital atrium. Genital pore median, on anterior edge of acetabulum.
Ovary acinous, usually 20–30 small lobes surrounding a central large lobe, 0.19–0.380.42–
0.78 as a whole, 29–46% of body length from anterior end. Oviduct arising from anterior borderof central lobe, running anterosinistrally, branching Laurer’s canal, receiving duct from seminal
receptacle at the same point where Laurer’s canalbranches, then passing anterodextrally, connecting vitelline reservoir, entering Mehlis’ gland.
Laurer’s canal convoluted, opening middorsallyin ovarian zone. Seminal receptacle transversely
elongate, 0.20–0.380.05–0.15, immediately anterior to ovary. Uterus filling available space ofhindbody. Eggs slender, thin-shelled, 18–228–
10 m m; two specimens with larger eggs 26–28
10–12 m m. Vitelline follicles usually in lateralfields, occasionally intruding inward, extending
from a level midway between intestinal bifurcation and acetabulum to ovarian level. Excretory
vesicle Y-shaped; arms reaching near prepharynx
or oral sucker; pore terminal.
Remarks. The present new species is mostsimilar to Siphoderina elongata (Gu et Shen,
1979) from the same genus of host Nemipterus,
but differs from it by having an oral sucker with28 to 35 circumoral spines, a ventrogenital sac
with thick wall, caeca ending blindly near the
middle of the posttesticular space, and vitelline
follicles extending from a level midway between
the intestinal bifurcation and acetabulum to theovarian level.
Siphoderina ryukyuensis sp. nov.
(Fig. 19)

Type host. Lutjanus kasmira (Forsskål) (Lutjanidae).
Other host. L. quinquelineatus (Bloch).
Site. Intestine.
Type locality. Koniya, Kagoshima Pref., 21XI-1989.
Other localities. Ishigaki-jima, Okinawa
Pref., 12-III-1973 and Nishinoomote, Kagoshima
Pref., 26-XI-1974.
Specimens. Holotype, NSMT-Pl 3811; and 7
paratypes, NSMT-Pl 1365, 1754 and 3811.
Etymology. The specific name ryukyuensis isfrom the locality, the Ryukyu Archipelago.
Description. Based on eight specimens.
Body fusiform with rounded ends, 1.57–2.55
long by 0.65–1.15 wide; length/width ratio 2.0–
2.8. Eyespot pigment in pharyngeal region. Dermal gland scattered in anterior half of body. Oral
sucker 0.12–0.200.14–0.21, with 19–25 circumoral spines; prepharynx 0.02–0.12 long; pharynx
0.07–0.120.08–0.11; esophagus 0.01–0.11
long; caeca usually passing interior sides oftestes, terminating near posterior end of body.
Acetabulum 0.07–0.110.08–0.12, embedded
in ventrogenital sac. Sucker ratio 1 : 0.49–0.61.
Forebody 23–33% of body length.
Testes longitudinally elongate, sometimes with
one to three depressions or incisions on exterior
surface, symmetrical or occasionally slightly diagonal; right testis 0.34–0.650.13–0.31; left
testis 0.33–0.580.15–0.33. Posttesticular space
13–25% of body length. Seminal vesicle bipartite, saccate, extending posteriorly anterior bor-

Cryptogonimidae from Fishes

der of ovary; pars prostatica 28–4022–30 m m;
genital pore median, near anterior edge of acetabulum.
Ovary acinous, 0.22–0.350.25–0.44, near
midbody. Oviduct arising from center of ovary,receiving duct from seminal receptacle, giving
off Laurer’s canal, joining vitelline reservoir, entering Mehlis’ gland. Seminal receptacle 0.12–
0.340.03–0.14, between acetabulum and ovary.
Laurer’s canal opening near posterior borderof ovary. Uterus running posteriorly along left
caecum, reaching near caecal ends, extending anteriorly along right caecum, both sides of ovary,connecting metraterm. Eggs 17–219–10 m m.
Vitelline follicles in lateral fields, extending froma level between intestinal bifurcation and acetabulum to near anterior edge of testes. Excretory
vesicle Y-shaped, bifurcating in ovarian region;arms reaching to oral sucker; pore terminal.
Remarks. The present new species can be
distinguished from all others in Siphoderina by

153

combination of the fusiform body; the oral sucker with 18 to 25 circumoral spines; the longitudinally elongate testes arranged symmetrically oroccasionally a little diagonally; the acinous
ovary; and the vitelline follicles in the lateralfields, extending from a level between the intestinal bifurcation and acetabulum to near the anterior edge of the testes.
Siphoderina xenocephali sp. nov.
(Fig. 20)Type host. Xenocephalus elongatus (Temminck et Schlegel) (Uranoscopidae).
Site. Intestine.
Type locality. Suruga Bay, 16-X-1973, 19–24III-1974.
Specimens. Holotype and 8 paratypes, MPM
Coll. No. 18234 and 18476.
Etymology. The specific name xenocephali isderived from the generic name of the host.

Fig. 19. Siphoderina ryukyuensis sp. nov. Entire worm, ventral view (holotype, NSMT-Pl 3811).
Fig. 20. Siphoderina xenocephali sp. nov. Entire worm, ventral view (holotype, MPM Coll. No. 18234).

154

Masaaki Machida

Description. Based on nine specimens. Body
elongate, rounded anteriorly and tapering posteriorly, 3.13–5.71 long by 0.87–1.25 wide; length/
width ratio 3.2–5.4. Tegument spinose. Dermal
gland densely developed in anterior half of body.
Oral sucker subterminal, 0.14–0.240.21–0.29,
with 44–51 circumoral spines. Cephalic glands
surrounding oral sucker, their ducts extending
anteriorly, opening between circumoral spines.
Prepharynx 0.03–0.17 long; pharynx 0.07–0.09
0.10–0.12; esophagus 0.06–0.29 long, bifurcating midway between suckers or closer to acetabulum; caeca narrow, terminating near middle ofposttesticular space. Acetabulum 0.15–0.21
0.15–0.22, embedded in ventrogenital sac. Ventrogenital sac surrounded by glandular cells andcircular muscle. Sucker ratio 1 : 0.70–0.85. Forebody 15–23% of body length.
Testes globular or subglobular, diagonal; righttestis 0.42–0.900.28–0.56; left testis 0.46–
0.780.36–0.54. It is not fixed which side of
testis is anterior. Posttesticular space 31–43% ofbody length. Seminal vesicle tubular, sinuous,
bipartite, extending posteriorly midway between
acetabulum and ovary or near ovary. Pars prostatica 80–90 m m long, whose distal end unites metraterm to form short genital atrium. Genital pore
median, on anterior edge of ventrogenital sac.
Ovary acinous, 0.30–0.460.53–0.74, attaching anterior edge of fore testis, lying 31–43% ofbody length from anterior end. Oviduct arisingfrom center of ovary, running forward, joining
short duct from seminal receptacle and giving off
Laurer’s canal, then curving backward to receive
vitelline reservoir, entering Mehlis’ gland. Seminal receptacle saccate, 0.11–0.260.25–0.40,
immediately anterior to ovary. Laurer’s canal
opening middorsally near posterior border ofovary. Uterus forming transverse loops, descending between testes, reaching near posterior end ofbody, then ascending between testes again, lateral
to ovary, mid-region between ovary and acetabulum. Metraterm very short. Eggs 19–239–11 m m. Vitelline follicles in lateral fields, between postacetabular level and midlevel of ovary.
Excretory vesicle Y-shaped, bifurcating immedi-

ately behind ovary; arms extending pharyngeal
level; pore terminal.
Remarks. The present new species is most
like S. onaga (Yamaguti, 1970) from Etelis coruscans, but differs from it by having caeca terminating near the middle of the posttesticularspace; a much longer posttesticular space; andvitelline follicles not forming bunch-like clusters.
The figure of S. onaga illustrated by Yamaguti(1970, Fig. 143A) shows the posttesticular spaceat a ratio of 19% of the body length.
Acknowledgements
I am grateful to the following fishermen’s cooperative associations for my field work: Owase,
Mie Pref.; Nishinoomote and Setouchi, Kagoshima Pref.; Nago and Ishigaki, Okinawa Pref. This
study was financially supported by the Watanabe
Memorial Foundation for the Advancement ofTechnology (No. 19–139).
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