Cardicola parilus, 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 : 36-39

Cardicola parilus n. sp.

( Figs 35–38 )

Type host: Siganus fuscescens (Houttuyn) , Black Spinefoot ( Perciformes : Siganidae ).

Site in host: Atrium and ventricle (heart).

Type locality: Ningaloo Reef (21°54.6’S 113°58.4’E), Western Australia .

Material examined: ex S. fuscescens, Ningaloo Reef (WA) , Aug. 2003, five specimens (nos. QM G 225232–225236 ) (another four specimens sequenced for ITS2) .

Collector: M.J. Nolan.

Etymology

Specific name from “ Parilis ” (L. equal, like), for the almost identical morphology of this species and C. lafii n. sp. from S. fuscescens off Lizard Island.

Description

Based on five whole mounts. With features of genus. Body lanceolate, 803–1024 (958) x 141–241 (194), 4.0–5.9 times longer than wide ( Figure 35 ). Tegumental spine rows 6–11 (8) wide; number of spines per row increasing from anterior and posterior ends toward middle of body, 5–8 anteriorly, 8–11 mid­body, 8–4 posteriorly, 8 in most. Nerve chords conspicuous; nerve commissure 77–90 (86) or 8–11% of body length from anterior end. Oral sucker vestigial, ovoid to spherical, 21–27 (24) x 21–27 (24), delimited posteriorly by fine membrane, bearing unknown number of concentric rows of fine spines. Mouth 6–13 (8) from anterior end ( Figure 36 ). Oesophagus sinuous, narrow anteriorly, widening posteriorly, surrounded by gland cells from posterior margin of nerve commissure to anterior margins of anterior caeca, 369–570 (467) or 39–58% of body length. Intestine X­ or H­shaped; anterior caeca unequal, right anterior caecum 70–198 (124) long, left anterior caecum 101–148 (117) long, length 10–18% of body length, wider than posterior pair, left anterior caecum dorsal to oesophagus; posterior caeca convoluted, unequal, right posterior caecum 305–564 (416) long, left posterior caecum 292–500 (417) long, length 29–54% of body length, 2.8–4.7 times longer than anterior pair, terminal extremities expanded. Testis mostly intercaecal, terminating anteriorly to termination of posterior caeca, 193–230 (210) or 20–24% of body length x 90–144 (126) or 37–81% of body width, 1.3–2.3 times longer than wide. Vas deferens originating at centre of posterior margin of testis, passing posteriorly sinuously, expanding distally to form seminal vesicle. Seminal vesicle elongate, tubular, 99–130 (121) or 10–13% of body length from posterior end, 55–128 (102) x 10–35 (25), 3.0–6.0 times longer than wide ( Figure 37 ). Ejaculatory duct dorso­anteriorly directed, convoluted; prostatic cells not seen. Male genital pore opening anteriorly to posterior margin of seminal vesicle. Ovary mostly dextrally orientated, anteriorly extending laterally to intercaecal field, extending dorso­anteriorly to posterior margin of testis, 55–132 (75) or 6–14% of body length x 67–144 (115) or 39–77% of body width, 180–315 (270) or 22–32% of body length from posterior end. Oviduct originating dorso­anteriorly to posterior margin of ovary, dextral, immediately expanding to form oviducal seminal receptacle, narrowing posteriorly to anterior margin of seminal vesicle, continuing posteriorly as narrow tube, joining with vitelline reservoir lateral to seminal vesicle. Oviducal seminal receptacle tear­shaped, dorsal to ovary, 29–93 (66) x 19–42 (33), 1.3–2.5 times longer than wide. Vitelline duct seen just posterior to anterior margin of testis, passing posteriorly ventral to testis, vas deferens and ovary, expands to form vitelline reservoir level with anterior margin of ovary, continues posteriorly ventral to oviducal seminal receptacle and oviduct. Oötype elliptical, lateral to male genital pore, surrounded by Mehlis’ gland, 19–48 (32) x 13–29 (18) wide. Mehlis’ gland extending anteriorly to joining of vitelline duct and oviducts, extending posteriorly to level of posterior margin of seminal vesicle. Uterus convoluted, passing posteriorly from oötype, looping antero­dorsally anterior to anterior margin of excretory vesicle, lateral to seminal vesicle passes posteriorly past oötype, passing anteriorly again dorsal to oötype, oviduct, Mehlis’ gland and vitelline reservoir, both dorsal and ventral to oviducal seminal receptacle, at posterior margin of ovary passes sinistrally across midline to enter metraterm. Metraterm retort­shaped, 35–118 (72) x 6–103 (38), dorsal to left posterior caecum anteriorly. Female genital pore opening laterally to posterior margin of oviducal seminal receptacle, anteriorly to anterior margin of seminal vesicle, antero­dextrally to male pore ( Figure 38 ). Eggs triangular to rounded in shape, 16–35 (25) x 10–22 (14) wide (n=23). Vitellarium follicular, anteriorly extending past nerve commissure, posteriorly extending 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, 4–14 (9) in diameter. Excretory pore terminal.

Remarks

The present material clearly belongs in the genus Cardicola . Cardicola parilus n. sp. is distinguished by the combination of a body 4.0–5.9 times longer than wide, posterior caeca that are convoluted and 2.8–4.7 times longer than the anterior pair, a testis that is mostly intercaecal, elliptical in shape and whose length extends 20–24% of the body length. The species differs further in having an ovary that is anteriorly intercaecal, mostly dextral in orientation and that is positioned 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 well developed retort­shaped metraterm.

m.

This species closely resembles C. lafii n. sp., from the atrium and ventricle of S. fuscescens , off Lizard Island. These species appear to differ in only three morphological characters; the width of the tegumental spines rows, the length/width ratio of the seminal vesicle and the distribution of the vitelline follicles. Cardicola parilus n. sp. possesses ventro­lateral transverse rows of tegumental spines 6–11 wide, a seminal vesicle 3.0–6.0 times longer than wide and a vitelline follicle distribution that extends anteriorly past the nerve commissure and posteriorly to the level of the metraterm. In contrast, C. lafii n. sp. possesses rows of tegumental spines 13–21 wide, a seminal vesicle 1.8–2.2 times longer than wide and vitelline follicles that fill the space from the posterior margin of the nerve commissure to the ovary.

Figures

FIGURES 35–38. Cardicola parilus n. sp. from the atrium and ventricle (heart) of Siganus fuscescens of Ningaloo Reef, Western Australia. 35. Adult, whole mount, ventral view. 36. Anterior region, ventral view, showing vestigial oral sucker delimited by fine membrane. 37. Male terminal genitalia, ventral view. Ejaculatory duct directed dorsally. 38. Female terminal genitalia, ventral view. Vitelline duct and vitelline reservoir omitted from figure as they obscure the path of the oviducal seminal receptacle and uterus as they pass posteriorly. Scale­bars: 35, 100 m; 36–38, 100