Hypocreadium toombo n. sp. (Digenea: Lepocreadiidae) in the yellowspotted triggerfish Pseudobalistes fuscus (Perciformes: Balistidae) and additional lepocreadiids parasitizing fishes from the waters off New Caledonia
Author
Bray, Rodney A.
Author
Justine, Jean-Lou
text
Zootaxa
2006
1326
37
44
journal article
10.5281/zenodo.273585
f2b78bf7-4c7a-4c18-9138-3961afe6a19c
11755326
273585
Hypocreadium toombo
n. sp.
(
Figs 1–2
)
Typehost:
Pseudobalistes fuscus
(Bloch & Schneider)
,
Balistidae
, yellowspotted triggerfish.
Site:
Intestine.
Typelocality:
Récif
Toombo
,
New Caledonia
(
22°26’S
,
166°33’E
,
13/12/2005
).
Typespecimens:
Holotype
MNHN JNC1680–D1;
paratypes
, MNHN JNC1680 D2–5, BMNH 2006.8.23.1–5.
FIGURES 1–2
.
Hypocreadium toombo
n. sp.
1.
Ventral view of holotype, uterus in bold outline.
2.
Terminal genitalia. Abbreviations: Ej, Ejaculatory duct; Ep, Excretory pore; Esv, External seminal vesicle; Isv, Internal seminal vesicle; Mt, Metraterm; Ov, Ovary; Pp, Pars prostatica; T, testis; Ut, Uterus.
Scale bars
: 1, 1 mm; 2, 200 μm.
Note on the host:
the specimen studied was
55 cm
in total length, the maximum recorded for this species (
Randall 2005
;
Froese & Pauly 2006
), and
4.7 kg
in weight.
Prevalence:
50%, 1/2, intensity 20; a second, smaller (
30 cm
,
0.80 kg
) fish, caught at Ilôt Signal, off Nouméa,
30/05/2006
, did not harbour this digenean.
Etymology:
This species is named after the reef from where the host was collected.
Description:
Based on
10 specimens
. Body almost circular, slightly longer than wide, flattened, distinct anterior notch present, 1,572–2,310 × 1,446–2,160 (2,026 × 1,863); width 89.3–97.4 (92.0) % of bodylength (
Figure 1
). No tegumental spines seen. Preoral lobe distinct, 27–54 (36) long. Oral sucker subglobular, with ventral aperture, 124–173 × 138–188 (149 × 167). Ventral sucker rounded, equatorial, 178–264 × 188–260 (230 × 228). Suckerlength ratio 1:1.32–1.78 (1.54); suckerwidth ratio 1:1.14–1.49 (1.36). Forebody 651–983 (860) long, 40.7–44.5 (42.4) % of bodylength. Prepharynx not seen. Pharynx broadly oval, 85–131 × 94–134 (109 × 117). Pharynx/oral sucker ratio 1:1.37–1.53 (1.43). Oesophagus distinct, 84–157 (111). Intestinal bifurcation in midforebody, 308–463 (402) from ventral sucker. Caeca narrow, irregularly arcuate around gonads, converge posteriorly, then turn anteriorly, terminating just posterior to testes; nearest approach to posterior extremity 282–556 (368).
Testes 2, irregularly oval, symmetrical, 234–362 × 211–345 (316 × 272), in anterior hindbody, separated by 165–260 (220). Posttesticular region 529–782 (663) long, 28.7–35.3 (32.7) % of bodylength. External seminal vesicle bi or tripartite, at level of ventral sucker, 145–389 × 71–145 (230 × 112). Cirrussac large, 417–632 × 195–251 (541 × 222), claviform, reaching from point dextrolateral to ventral sucker diagonally across posterior forebody, surrounded by glandcells; length 23.9–29.6 (26.7) % of bodylength. Internal seminal vesicle oval, in proximal end of cirrussac. Pars prostatica large, vesicular, folded, lined with large anuclear celllike bodies (
Figure 2
). Ejaculatory duct muscular, long, complexly folded, lined with tessellated surface of distinct protruding bosses, becoming larger distally. Genital atrium distinct. Genital pore just sinistral to intestinal bifurcation or just postbifurcal, 247–399 (337) from ventral sucker.
Ovary more or less oval, intertesticular, 172–257 × 130–196 (214 × 162), usually contiguous with sinistral testis, but separated by up to 38, separated by uterus from dextral testis, 12–92 (36) from ventral sucker. Postovarian region 528–820 (675) long, 30.9–35.5 (33.3) % of bodylength. Seminal receptacle large, saccular, between sinistral testis and ventral sucker. Laurer’s canal opens dorsally to ovary or between ovary and closest testis. Mehlis’ gland anterior to ovary. Uterus passes between ovary and dextral testis into postovarian region, then anteriorly, narrowing dorsally to ventral sucker, then widens to form metraterm. Metraterm passes anteriorly, with thick muscular wall and sheath of glandcells, often dilated with eggs, 442–708 (587) long. Postuterine distance 407–613 (506), 22.9–26.5 (25.0) % of bodylength. Eggs tanned, operculate, 63–79 × 33–39 (70 × 36). Vitellarium follicular; follicles numerous, surround gonads, well separated from bodymargins, contiguous or nearly so prebifurcally, contiguous or not immediately postbifurcally where follicles may form continuous narrow band dorsal to terminal genitalia, contiguous posteriorly, lateral, dorsal and median to caeca but not ventral; previtelline distance 194–287 (256), 8.97–14.9 (12.7) % of bodylength; postvitelline distance 157–252 (208), 7.72–11.4 (10.3) % of bodylength.
Excretory pore dorsal to posterior extension of uterus, between caeca. Extent of vesicle obscured by eggs, arms of excretory system reach into forebody laterally to level of oesophagus or pharynx.