Braya jexi, 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 : 58-59

Braya jexi n. sp.

( Figs 55–58 )

Type host: Scarus frenatus (Lacepède) , Bridled Parrotfish ( Perciformes : Scaridae ).

Site in host: Atrium (heart).

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

Material examined: ex S. frenatus, Heron Island ( QLD), May. 2003, Feb. 2005, three specimens (nos. QM G 225256–225258 ) (another five specimens sequenced for ITS2) .

Prevalence of infection: Five of eleven S. frenatus off Heron Island infected with eight specimens .

Collector: M.J. Nolan.

Etymology

Specific name for our good friend and colleague Mr Aaron R. Jex of the School of Molecular and Microbial Sciences (UQ).

Description

Based on three whole mounts. With features of genus. Body lanceolate, anterior margin emarginate, posterior margin truncate, 1387–1761 (1518) x 232 x 122–161 (142), 7.6 times longer than wide ( Figures 55 ). Tegumental spine rows 8–24 (16) wide; number of spines per row increasing from anterior and posterior ends toward middle of body, 4 anteriorly, 9–10 mid­body, 10–8 posteriorly. Nerve chords conspicuous; nerve commissure 114–161 (135) or 8–9% of body length from anterior end. Oral sucker transversely rhomboidal, 20–21 (21) x 26 x 23, delimited posteriorly by fine membrane ( Figure 56 ). Mouth 7–10 (9) from anterior end. Oesophagus narrow anteriorly and posteriorly, widest and deepest medially, surrounded by gland cells medially and posteriorly to intestinal bifurcation, 525–688 (607) or 38–39% of body length. Intestine X­shaped; anterior caeca unequal, right anterior caecum 104–155 (130) long, left anterior caecum 110–167 (195) long, length 8–9% of body length, irregular in outline, ventral to oesophageal gland cells, anterior extremities expanded; posterior caeca sinuous, convoluted, unequal, right posterior caecum 368–412 (390) long, left posterior caecum 478–485 (483) long, length 28–34% of body length, 2.9–4.3 times longer than anterior pair, posterior extremities may be expanded. Testis originating at posterior of intercaecal field, extending largely laterally and posteriorly to field, rectangular with irregular lateral margins, anterior margin rounded, posterior margin truncate, 307 or 22% of body length x 80 or 66% of body depth, 3.8 times longer than deep, containing dorso­ventral muscle fibres. Vas deferens narrow, passing posteriorly sinuously, then dorsally, expanding distally to form seminal vesicle. Seminal vesicle lanceolate, sinuous (dorso­ventral view), oblanceolate (lateral view), 75–90 (81) or 5–6% of body length from posterior end (taken from point where narrows to thin tube before male genital pore), 121–183 (145) x 39 x 54, 4.7 times longer than wide. Male genital pore opening terminally and medially at posterior end of body ( Figure 57 ). Ovary entirely posterior to intercaecal field, abutting or slightly overlapping posterior margin of testis, dextral in orientation, irregular in shape, 49–98 (72) or 3–6% of body length x 106 or 46% of body width x 62–106 (84) or 51–66% of body depth; 298–416 (344) or 21–24% of body length from posterior end. Oviduct originating at posterior margin of ovary, dextrally, passing posteriorly then dorso­dextrally, expanding to form oviducal seminal receptacle, narrowing lateral to anterior margin of seminal vesicle, then passing antero­sinistrally ventrally, joining with vitelline duct lateral to anterior margin of seminal vesicle ( Figures 58 ). Oviducal seminal receptacle ovoid to oblanceolate, 114–163 (130) x 28 x 36, 5.8 times longer than wide, dorsal to vas deferens. Vitelline duct seen anterior to posterior margin of testis, passing posteriorly dextrally, narrow, straight, ventral to testis, vas deferens (in part), ovary, oviducal seminal receptacle and oviduct. Oötype elliptical to ovoid, antero­sinistrally directed, ventrally, lateral to anterior margin of seminal vesicle and posterior margin of oviducal seminal receptacle, 41–65 (50) x 41 x 21–23 (22). Mehlis’ gland extends anteriorly to anterior margin of oötype, extending posteriorly past anterior margin of seminal vesicle. Uterus convoluted, sinuous, passing antero­sinistrally from oötype, dorsal to vas deferens, then postero­dextrally to just anterior of joining of oviduct and vitelline duct, lateral to oviducal seminal receptacle passes anteriorly along midline, dorsal to vitelline duct and vas deferens, lateral to origin of oviduct passes antero­sinistrally across midline to sinistral posterior margin of ovary, here loops posteriorly, lateral to anterior margin oviducal seminal receptacle joins metraterm. Metraterm narrow, convoluted proximally, straight distally, 147–163 (155) x 16 x 13–24 (19). Female genital pore sinistral, opening posteriorly to female genitalia, antero­sinistrally to male pore. Eggs ovoid, 21–31 (25) x 15–21 (18) (n=16). Vitellarium follicular, extending anteriorly to posterior margin of nerve commissure, laterally past the lateral nerve chords, extending posteriorly to posterior margin of testis, anteriorly dorsal to lateral nerve chords, both dorsal and ventral to oesophagus, intestine and testis, posteriorly ventral to ovary. Excretory vesicle obovate to spherical, 8 wide, collecting ducts seen extending anteriorly from anterior margin of vesicle. Excretory pore subterminal, opening anteriorly to male genital pore.

Remarks

Braya jexi n. sp. agrees well with the characters of Braya n. gen. and is easily distinguished by having the combination of a body 7.6 times longer than wide, an oesophagus that extends almost 40% of the body length, anterior and posterior caeca that are straight and that extend 8–9% and 28–34% of the body length (respectively), a testis that is almost entirely posterior to the intercaecal field (although overlapping the posterior margin of the right posterior caecum), an ovary occupying 46% of the body width, an oviducal seminal receptacle 5.8 times longer than wide, a uterus that extends anteriorly lateral to the ovary (instead of being entirely postovarian as in P. psittacus n. sp.) and vitelline follicles that extend posteriorly to the anterior margin of the ovary (instead of past the posterior margin as in P. psittacus n. sp. and P. yantschi n. sp.).

Figures

FIGURE 55. Braya jexi n. sp. from the atrium (heart) of Scarus frenatus off Heron Island. Adult, whole mount. A. Lateral view. B. Dorso­ventral view. Scale­bars: 250 m.

FIGURES 56–58. Braya jexi n. sp. 56. 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. 57. Male terminal genitalia. A. Ventral view. B. Lateral view. Sperm has moved away from the wall of the seminal vesicle to give the appearance of a double wall (and thus illustrate a cirrus­sac); this is not the case. The male terminal genitalia of Braya n. gen. species consists of a seminal vesicle only. 58. Female terminal genitalia. A. 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. B. Lateral view; ovary, oviducal seminal receptacle, and oötype figured only. Scale­bars: 200 m.