Cardicola tantabiddii, 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 : 39-42

Cardicola tantabiddii n. sp.

( Figs 39–42 )

Type host: Siganus fuscescens (Houttuyn) , Black Spinefoot ( Perciformes : Siganidae ). Site in host: Atrium and ventricle (heart). Type locality: Tantabiddi, Ningaloo Reef (21°54.6’S 113°58.4’E), Western Australia. Material examined: ex S. fuscescens, Ningaloo Reef (WA) , Aug. 2003, three specimens (nos. QM G 225238–225240) (one specimen sequenced for ITS2). Collector: M.J. Nolan.

Etymology Specific name for the location from which this species was collected.

Description

Based on three whole mounts. With features of genus. Body elliptical, 1262–1306 (1280) x 382–395 (388), 3.3 times longer than wide, widest level with intestinal bifurcation ( Figure 39 ). Tegumental spine rows 8 wide; number of spines per row increasing in number from anterior and posterior ends toward middle of body, 5–7 anteriorly, 8–11 mid­body, 8–4 posteriorly, 8 in most. Nerve chords conspicuous; nerve commissure 83–96 (92) or 7–8% of body length from anterior end. Oral sucker vestigial, spherical, 19–25 (23) x 24, delimited posteriorly by fine membrane, bearing unknown number of concentric rows of fine spines ( Figure 40 ). Mouth 6–7 (7) from anterior end. Oesophagus sinuous, narrow anteriorly, wide posteriorly, surrounded by gland cells from posterior margin of nerve commissure to anterior margin of right anterior caecum, cells obscure oesophagus medially, 601–638 (614) or 46–50% of body length. Intestine X­ or H­shaped; anterior caeca unequal, right anterior caecum 104–198 (162) long, left anterior caecum 134–238 (170) long, length 10–19% of body length, irregular in outline, ventral to oesophageal gland cells, left anterior caecum wider than right caecum; posterior caeca not clear (although exact outline not seen, can be discerned from testis and vitelline follicles by colour of intestinal contents), assumed convoluted by comparison to anterior most regions, posterior extremities expanded. Testis mostly intercaecal, irregular in shape, 311–369 (345) or 24–28% of body length x 250–257 (255) or 63–67% of body width, 1.2–1.5 times longer than wide. Vas deferens originating at centre of posterior margin of testis, passing posteriorly sinuously, expands distally to form seminal vesicle. Seminal vesicle tubular, width consistent, 56–70 (61) or 4–6% of body length from posterior end, 106–112 (109) x 16–19 (17), 5.8–6.6 times longer than wide ( Figure 41 ). Ejaculatory duct not seen; prostatic cells not seen. Male genital pore opening sub­marginally. Ovary rectangular, extending laterally and posteriorly to intercaecal field, extending dorsoanteriorly to posterior margin of testis, 103–144 (131) or 8–12% of body length x 257–276 (269) or 67–71% of body width; 140–147 (144) or 11% of body length from posterior end. Oviduct originating at centre of posterior margin of ovary, expanding to form oviducal seminal receptacle posterior to ovary, narrowing anteriorly to anterior margin of seminal vesicle, joining with vitelline duct lateral to posterior margin of seminal vesicle. Oviducal seminal receptacle ovoid, 64–83 (74) x 27–45 (38), 1.8–2.4 times longer than wide. Vitelline duct seen near anterior margin of testis, collecting ducts seen extending laterally from main medial duct, passing posteriorly, ventral to testis and vas deferens, expanding to form vitelline reservoir level with anterior margin of ovary, continuing posteriorly ventral to ovary, oviducal seminal receptacle and oviduct. Oötype elliptical to lanceolate, lateral to posterior margin of seminal vesicle, 24–35 (32) x 14–22 (20). Mehlis’ gland extends anteriorly to joining of vitelline and oviducts, laterally to posterior margin of seminal vesicle and posteriorly to level of male genital pore. Uterus convoluted, passing posterosinistrally from oötype, loops dorso­anteriorly anterior to anterior margin of excretory vesicle, posterior to posterior margin of oviducal seminal receptacle passes sinistrally across midline, dorsal to vitelline duct and vas deferens, at posterior margin of ovary passing postero­dextrally to anterior margin of seminal vesicle, here passes anterosinistrally to join metraterm ( Figure 42 ). Metraterm thin, tubular, 32–48 (42) x 8. Female genital pore opening sinistrally, posteriorly to posterior margin of oviducal seminal receptacle, anteriorly to anterior margin of seminal vesicle and antero­dextrally to male pore. Eggs ovoid, 16–29 (23) x 10–22 (16) (n=10). Vitellarium follicular, anteriorly extending past nerve commissure, laterally past lateral nerve chords, and 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 cuneate, 5–8 (6) wide; collecting ducts seen extending anteriorly from anterior margin of vesicle. Excretory pore terminal.

Remarks

Cardicola tantabiddii n. sp. is distinguished from its congeners by possessing the combination of a body 3.3 times longer than wide, the nerve commissure 7–8% of the body length from the anterior end, an oesophagus that extends about 50% of the body length, an irregularly shaped testis that is mostly intercaecal, an elongate tubular seminal vesicle 5.8–6.6 times longer than wide and 4–6% of the body length from the posterior end and a male genital pore that opens posteriorly to the oötype. This species also differs in having a rectangular ovary that extends laterally but not posteriorly to the intercaecal field and that is positioned 11% of the body length from the posterior end, an oviducal seminal receptacle that is entirely anterior to the seminal vesicle and a uterus that is entirely posterior to both the posterior caeca and the ovary.

Cardicola tantabiddii n. sp. most closely resembles C. parilus n. sp. in that both species are from Siganus fuscescens from Ningaloo Reef, and possess convoluted posterior caeca, a testis that is irregular in shape and mostly intercaecal and a uterus that extends posteriorly from the oötype before looping anteriorly. Cardicola tantabiddii n. sp. differs in having a seminal vesicle 4–6% of the body length from the posterior end, a male genital pore that opens posteriorly to the oötype, an ovary that is rectangular, medial and 11% of the body length from the posterior end, an oviducal seminal receptacle that is anterior to the seminal vesicle and a small tubular metraterm. In contrast, C. parilus n. sp. possesses a seminal vesicle 10–14% of the body length from the posterior end, a male genital pore that opens laterally to the oötype, an ovary that is transversely oblanceolate, mostly dextrally orientated and 22–32% of the body length from the posterior end, an oviducal seminal receptacle that extends posteriorly past the posterior margin of the seminal vesicle and a large retort­shaped metraterm.

Figures

FIGURES 39–42. Cardicola tantabiddii n. sp. from the atrium and ventricle (heart) of Siganus fuscescens of Ningaloo Reef, Western Australia. 39. Adult, whole mount, ventral view. Oesophagus obscured medially by gland cells. Posterior caecal outline not seen, assumed convoluted by coloration of intestinal contents. 40. Anterior region, ventral view, showing vestigial oral sucker delimited by fine membrane. 41. Male terminal genitalia, ventral view. Seminal vesicle tubular, thin. 42. Female terminal genitalia, ventral view. Vitelline duct and vitelline reservoir omitted from figure as they obscure the path of the oviduct, oviducal seminal receptacle and uterus as they pass posteriorly. Scale­bars: 39,41,42, 250 m; 40, 100 m.