Cardicola chaetodontis Yamaguti 1970

(Figs 43–46)

Material examined: ex Chaetodon aureofasciatus (Macleay), Lizard Island (QLD), Dec. 2000, one specimen (QM G 225242); ex C. citrinellus, Moorea (French Polynesia), Dec. 1999, one specimen (QM G 225243); C. lineolatus (Cuvier), New Caledonia, Nov. 1997, one specimen (QM G 225244); C. reticulatus (Cuvier), Moorea (French Polynesia), Dec. 1999, one specimen (QM G 225245); and C. unimaculatus (Bloch), Palau, Dec. 2001, one specimen (QM G 225246), Heron Island, Feb. 2005, one specimen. (Perciformes: Chaetodontidae).

Locality: 1. Heron Island; 2. Lizard Island; 3. Moorea; 4. Ningaloo Reef; 5. New Caledonia; 6. Palau; 7. Swain Reefs Complex.

Records: 1. Yamaguti (1970). 2. Present study.

Site in host: Heart (1,2), gills (1), blood vessels of the intestine (2).

Host: C. aureofasciatus (2), C. citrinellus (2), C. flavirostris (Günther) (2), C. fremblii (1), C. lineolatus (2), C. miliaris (1), C. reticulatus (2), C. ulietensis (Cuvier) (2) and C. unimaculatus (2), (Perciformes: Chaetodontidae).

Localities: Hawaii (1), Heron Island, southern Great Barrier Reef (23º26’S 151º54’E), Queensland (2), Lizard Island, northern Great Barrier Reef (14°40’S 145°27’E), Queensland (2), Palau (7°30’N 134°30’E) (2), Moorea (15°00’S 140°00’W) (2) and New Caledonia (21°30’S 165°30’E) (2).

Prevalence of infection: Refer Table 4.

Collectors: R.D. Adlard, R.A. Bray, T.H. Cribb, D.T.J. Littlewood, P. Sasal and M.J. Nolan.

Description

Based on five complete and partial mounts. With features of genus. Body elliptical, 899–1396 (1194) x 119–257 (196), 4.3–7.0 times longer than wide (Figure 43). Tegumental spine rows 5–8 (6) wide; width consistent along length, 5–6 spines per row. Nerve chords conspicuous; nerve commissure 87–111 (100) or 7–10% of body length from anterior end. Oral sucker vestigial, rhomboidal, 11–16 (13) x 8–19 (15) wide, delimited posteriorly by fine membrane, bearing unknown number of concentric rows of fine spines (Figure 44). Mouth 3 from anterior end. Oesophagus sinuous, width consistent along length, gland cells not seen, 332–475 (397) or 33–37% of body length. Intestine X­shaped; anterior caeca unequal, right anterior caecum 19–35 (30) long, left anterior caecum 30–64 (40) long, length 2–5% of body length; posterior caeca unequal, right posterior caecum 158–498 (337) long, left posterior caecum 163–546 (345) long, length 29–39% of body length, 5.4–12.5 times longer than anterior pair, terminal extremities slightly expanded. Testis ovoid with irregular margins, mostly intercaecal, 321–530 (450) or 36–38% of body length x 64–161 (107) or 41–66% of body width; 3.1–5.5 times longer than wide. Vas deferens originating dextrally, anteriorly to posterior margin of testis, passing posteriorly ventral to testis, expands distally to form seminal vesicle. Seminal vesicle sinistral, ovoid, 109–178 (146) or 10–15% of body length from posterior end, 32–56 (44) x 10–19 (14), 2.9–3.5 times longer than wide (Figure 45). Ejaculatory duct not seen; prostatic cells not seen. Male genital pore opening laterally to seminal vesicle. Ovary dextral to medial in orientation, posterior to intercaecal field and posterior margin of testis, dorsal to vas deferens, 80–225 (128) or 7–16% of body length x 45–170 (108) or 32–73% of body width; 193–282 (237) or 17–24% of body length from posterior end. Oviduct originating at posterior margin of ovary, dextrally, passing posteriorly as straight tube, expanding to form oviducal seminal receptacle anteriorly to anterior margin of seminal vesicle, joining with vitelline duct lateral to seminal vesicle, entering oötype anteriorly. Oviducal seminal receptacle small, ovoid, 32–48 (39) x 13–32 (19), 1.3–3.8 times longer than wide. Vitelline duct seen anteriorly to posterior margin of testis, passing posteriorly, ventral to vas deferens and ovary. Oötype elliptical, posterior to seminal vesicle, 22–96 (44) x 13–26 (20). Mehlis’ gland extending anteriorly to oviducal seminal receptacle, extending posteriorly past terminal genitalia. Uterus passing posteriorly from oötype, curving anterosinistrally, then medially, dorsal to vitelline duct, ventral to seminal vesicle and vas deferens, at posterior margin of ovary passes posteriorly, anterior to oviducal seminal receptacle loops anteriorly to join with metraterm (Figure 46). Metraterm thin, 32–128 (86) x 13–35 (22). Female genital pore opening anteriorly to oviducal seminal receptacle, antero­dextrally to male pore. Eggs ovoid, 19–33 (25) x 10–24 (17) (n=31). Vitellarium follicular, extending anteriorly past nerve commissure, extending laterally past lateral nerve chords, extending posteriorly to posterior margin of ovary, anteriorly dorsal to lateral nerve chords, both dorsal and ventral to oesophagus, intestine and testis, posteriorly ventral to ovary. Excretory vesicle 6 in diameter. Excretory pore terminal.

Remarks

Our specimens agreed well with the original description of Yamaguti (1970) with the exception of body shape adjacent to the male genital pore, the position of the male genital pore, the shape of the ovary and vitelline follicle distribution. Yamaguti (1970) stated that the right margin of the body, level with the male pore, “bulges out laterally in form of a dome” and that the ovary is bilobed. In contrast, this study found no such structure associated with the male pore that was situated near the left body wall while the ovary was found to be irregular in shape and dextral to medial in orientation. In contrast to the original description (Yamaguti 1970), vitelline follicle distribution in the present material was found to extend anteriorly to the nerve commissure.

Yamaguti (1970) originally described the anterior end of C. chaetodontis as having a “small dome­shaped projection on the ventral side of which opens the small cuticularized mouth aperture”. Examination of the present material suggests this structure to be analogous to an oral sucker (albeit vestigial).