Cardicola coeptus, Nolan & Cribb, 2006

Nolan, Matthew J. & Cribb, Thomas H., 2006, Cardicola Short, 1953 and Braya n. gen. Digenea: Sanguinicolidae) from five families of tropical Indo-Pacific fishes (, Zootaxa 1265 (1), pp. 1-80 : 19-22

Cardicola coeptus n. sp.

( Figs 15–18 )

Type host: Siganus punctatus (Schneider) , Goldspotted Rabbitfish ( Perciformes : Siganidae ).

Other hosts: Siganus vulpinus (Schlegel and Müller) , Foxface ( Perciformes : Siganidae ).

Site in host: Atrium and ventricle (heart) and gills.

Type locality: Heron Island, southern Great Barrier Reef (23º26’S 151º54’E), Queensland .

Material examined: ex S. punctatus, Heron Island ( QLD), Feb. 2002, Feb. 2005, twenty specimens (nos. QM G 225218–225222 ) (eight specimens sequenced for ITS2); ex S. vulpinus, Heron Island ( QLD), Feb. 2002, one specimen (no QM G 225223 ) (another one specimen sequenced for ITS2) .

Prevalence of infection: Five of sixteen S. punctatus from Heron Island infected with twenty specimens; two of thirteen S. vulpinus from Heron Island infected with two specimens

Collector: M.J. Nolan.

Etymology

Specific name from “ Coeptus ” (L. begin, commence, undertake) as this new species provided the starting point of the present study.

Description

Based on twelve whole mounts. With features of genus. Body elliptical, 1239–1457 (1329) x 321–417 (371), 3.2–4.1 times longer than wide, anterior and posterior ends rounded ( Figure 15 ). Tegumental spine rows 10–29 (19) wide, number of spines per row increasing from anterior and posterior ends toward middle of body, 4–7 anteriorly, 8–11 mid­body, 8–5 posteriorly, with 7–9 in most. Nerve chords conspicuous; nerve commissure 90–135 (113) or 7–10% of body length from anterior end. Oral sucker vestigial, cuspidate anteriorly, rounded posteriorly, 25–33 (28) x 24–40 (31), delimited posteriorly by fine membrane, bearing unknown number of concentric rows of fine spines ( Figure 16 ). Mouth 6–19 (12) from anterior end. Oesophagus sinuous, narrow anteriorly, widening posteriorly to posterior margin of nerve commissure, surrounded by gland cells medially, 700–940 (817) or 56–67% of body length. Intestine X­shaped; anterior caeca unequal, right anterior caecum 100–210 (162) long, left anterior caecum 100–200 (155) long, length 8–14% of body length, left anterior caecum dorsal to oesophagus; posterior caeca sinuous, unequal, right posterior caecum 400–580 (477) long, left posterior caecum 350–560 (461) long, length 28–38% of body length, 2.3–4.8 times longer than anterior pair, terminal extremities expanded. Testis square to rectangular with irregular margins, extending anteriorly and laterally to intercaecal field, terminating anteriorly to termination of posterior caecum, 241–273 (254) or 18–22% of body length x 180–295 (227) or 44–92% of body width, 0.9–1.1 times longer than wide. Vas deferens originating at posterior margin of testis, medially, passing posteriorly sinuously, expanding distally to form seminal vesicle. Seminal vesicle elliptical, 151–173 (161) or 11–13% of body length from posterior end, 96–177 (127) x 16–67 (41), 1.8–9.2 times longer than wide ( Figure 17 ). Ejaculatory duct thin, straight, posteriorly directed; prostatic gland cells small. Male genital pore sinistral, sub­marginal. Ovary extending laterally to intercaecal field, extending dorso­anteriorly to posterior margin of testis, dorsal to vas deferens, 64–90 (71) or 4–7% of body length x 209–257 (228) or 62–69% of body width, 291–324 (312) or 22–25% of body length from posterior end. Oviduct originating at centre of posterior margin of ovary, looping dorso­dextrally, expanding to form oviducal seminal receptacle, narrowing level with termination of right posterior caecum, continuing posteriorly as narrow tube, joining with vitelline duct lateral to posterior margin of seminal vesicle. Oviducal seminal receptacle ovoid, 39–77 (61) x 29–48 (39), 1.3–1.8 times longer than wide, dorsal to right posterior caecum. Vitelline duct seen just posterior to posterior margin of testis, passing posteriorly, ventral to right posterior caecum, vas deferens, ovary, oviducal seminal receptacle and oviduct. Oötype spherical to ovoid, lateral to posterior margin of seminal vesicle, 32–71 (48) x 26–64 (38). Mehlis’ gland extending anteriorly past seminal vesicle, extending posteriorly past terminal genitalia. Uterus convoluted, passing postero­sinistrally from oötype, looping dorsally posterior to seminal vesicle, then passing anteriorly to anterior margin of seminal vesicle, here looping dorso­posteriorly to posterior margin of oötype, then passing anteriorly again, dorsal to vas deferens and oviduct, ventral to oviducal seminal receptacle, at posterior margin of oviducal seminal receptacle passes sinistrally across midline, looping posteriorly to join metraterm ( Figure 18 ). Metraterm tapering posteriorly, passing dorsally, 80–193 (122) x 13–58 (29). Female genital pore opening medially, posteriorly to oviducal seminal receptacle, anteriorly to seminal vesicle, antero­dextrally to male genital pore. Eggs ovoid, 22–45 (31) x 16–29 (22) (n=22). Vitellarium follicular, filling space from posterior margin of nerve commissure to posterior margin of oviducal seminal receptacle, anteriorly dorsal to lateral nerve chords, both dorsal and ventral to oesophagus, intestine and testis, posteriorly ventral to ovary. Excretory vesicle cuneate, 10–16 (12) in diameter; collecting ducts directed anteriorly, seen to extend to posterior extremity of Mehlis’ gland. Excretory pore terminal.

Remarks

Cardicola coeptus n. sp. agrees well with the characters of Cardicola and is easily distinguished from the 14 reported species by having the combination of a body 1239–1457 (1329) x 321–417 (371), an oral sucker, a sinuous oesophagus that extends 56–67% of the body length, a testis that extends laterally to the intercaecal field, a seminal vesicle positioned anterior to the oötype and a male genital pore that opens laterally to the oötype. This species also differs from its congeners in having an ovary that is almost entirely intercaecal (extending laterally but not posteriorly to the intercaecal field) and medial, and 64–90 (71) x 209–257 (228), an oviducal seminal receptacle that is anteriorly intercaecal and 1.3–1.8 times longer than wide, a vitelline duct that joins with the oviduct posterior to the posterior margin of the seminal vesicle, a convoluted uterus that extends anteriorly as far as the posterior termination of the intercaecal field and a female genital pore that opens between the oviducal seminal receptacle and the oötype sinistrally.

The present material most closely resembles C. milleri n. sp. from Lutjanus bohar off Lizard Island. These species share a combination of characters, including, an oral sucker, a sinuous oesophagus, an intestine that is irregular in outline, posterior caeca that extend less than 38% of the body length, a testis that extends laterally but not posteriorly to the intercaecal field, a seminal vesicle positioned laterally or anterior to the oötype, a male genital pore that opens laterally to the oötype, an ovary width no more than 69% of the body width and 29% of the body length from the posterior end and a female genital pore that opens anterior to the oötype. These species differ however, in at least five characters. Cardicola milleri n. sp. possesses oesophageal gland tissue that extends posteriorly to the intestinal bifurcation, a testis that extends anteriorly to the intercaecal field (albeit only slightly), an ovary that extends posteriorly to the intercaecal field, an oviducal seminal receptacle that is entirely posterior to the intercaecal field and vitelline follicles that extend posteriorly to the anterior margin of the oviducal seminal receptacle. In contrast, C. coeptus n. sp. possesses oesophageal gland tissue that extends posteriorly to the anterior margins of the anterior caeca, a testis that does not extend anteriorly to the intercaecal field, an ovary that does not extend posteriorly to the intercaecal field, an oviducal seminal receptacle that is anteriorly intercaecal and vitelline follicles that extend posteriorly to the posterior margin of the oviducal seminal receptacle.

Figures

FIGURES 15–18. Cardicola coeptus n. sp. from the atrium and ventricle (heart), and the gills of Siganus punctatus off Heron Island. 15. Adult, whole mount, ventral view. Mehlis’ gland not seen in this specimen. 16. Anterior region, ventral view, showing vestigial oral sucker delimited by fine membrane. Although spines seen on sucker exact number of concentric rows not clear, spines illustrated to show their presence only. 17. Male terminal genitalia, dorsal view. 18. Female terminal genitalia, dorsal view. Vitelline duct omitted from figure as it obscures the path of the uterus as it passes posteriorly. Scale­bars: 15, 250 m; 16–18, 100 m.