Braya yantschi, 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 : 55-56

Braya yantschi n. sp.

( Figs 51–54 )

Type host: Chlorurus microrhinos (Bleeker) , Steephead Parrotfish ( Perciformes : Scaridae ).

Site in host: Atrium (heart).

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

Material examined: ex C. microrhinos, Heron Island ( QLD), May. 2003, Feb. 2005, five specimens (nos. QM G 225251–225255 ) (eight specimens sequenced for ITS2) .

Prevalence of infection: Three of six C. microrhinos off Heron Island infected with thirteen specimens.

Collector: M.J. Nolan.

Etymology Specific name for our good friend Mr Jonathan Yantsch for his efforts in the field.

Description

Based on five whole mounts. With features of genus. Body elliptical, 1413–1600 (1550) x 310–393 (355), 3.6–5.1 times longer than wide ( Figure 51 ). Tegumental spine rows 8–34 (18) wide; number of spines per row increasing from anterior and posterior ends toward middle of body, 4–10 anteriorly, 8–10 mid­body, 10–7 posteriorly. Nerve chords conspicuous; nerve commissure 65–96 (80) or 4–6% of body length from anterior end. Oral sucker with anterior margin rounded, posterior margin cuneate, 23–31 (27) x 26–33 (29), delimited posteriorly by fine membrane ( Figure 52 ). Mouth 3–13 (9) from anterior end. Oesophagus narrow anteriorly and posteriorly, widening medially, surrounded by gland cells medially and posteriorly to level intestinal bifurcation, 450–780 (615) or 29–55% of body length. Intestine X­shaped; anterior caeca unequal, right anterior caecum 167–200 (186) long, left anterior caecum 147–200 (167) long, length 10–13% of body length, irregular in outline, may possess diverticules, ventral to oesophageal gland cells; posterior caeca sinuous, unequal, right posterior caecum 462–555 (509) long, left posterior caecum 490–590 (540) long, length 31–37% of body length, 2.5–3.8 times longer than anterior pair, irregular in outline. Testis originating in anterior half of intercaecal field, extending laterally and posteriorly to field, extending posteriorly further sinistrally than dextrally, rectangular with irregular margins, 240–416 (355) or 17–26% of body length x 176–304 (268) or 73–94% of body width, 0.8–2.1 times longer than wide, containing dorso­ventral muscle fibres. Vas deferens seen anterior to anterior margin of testis, passing posteriorly sinuously, ventral to testis, expanding distally to form seminal vesicle. Seminal vesicle lanceolate, sinuous, 51–127 (89) or 3–8% of body length from posterior end, 143–179 (159) x 34–70 (54), 2.3–4.2 times longer than wide. Male genital pore opening dorso­medially at posterior end of body, sub­terminally ( Figure 53 ). Ovary entirely posterior to intercaecal field, abutting posterior margin of testis, dextral to medial in orientation, rectangular to ovoid, margins very irregular, 68–199 (136) or 4–12% of body length x 85–204 (137) or 26–66% of body width; 170–359 (294) or 11–23% of body length from posterior end. Oviduct originating at centre of posterior margin of ovary, passing posteriorly then antero­dextrally, looping ventro­sinistrally, expanding to form oviducal seminal receptacle, narrowing level with anterior margin of seminal vesicle, passing posteriorly then antero­sinistrally to oötype. Oviducal seminal receptacle elliptical to ovoid, 114–196 (162) x 37–65 (47), 3.0–4.3 times longer than wide, dextrally orientated. Vitelline duct seen anterior to posterior margin of testis, straight, narrow anteriorly, expanding slightly to form vitelline reservoir lateral to ovary, posteriorly narrowing again, passing posteriorly ventral to testis, vas deferens, ovary, oviduct and oviducal seminal receptacle. Oötype elliptical to ovoid, antero­sinistrally directed, lateral to anterior margin of seminal vesicle and oviducal seminal receptacle, 52–73 (61) x 33–41 (37). Mehlis’ gland not seen. Uterus sinuous, passing antero­sinistrally from oötype, dorsal to vas deferens, then postero­dextrally to posterior margin oötype, lateral to oötype passes anteriorly along midline, dorso­sinistrally to oviducal seminal receptacle and vitelline duct, to posterior margin of ovary, here passes antero­sinistrally across midline, dorsal to ovary, then anteriorly past sinistral posterior margin of testis, dorsal to testis loops posteriorly to join metraterm. Metraterm muscular, narrow, straight, 122–171 (147) x 23–29 (25). Female genital pore sinistral, opening posteriorly to female genitalia, anterosinistrally to male pore ( Figure 54 ). Eggs ovoid, 18–29 (24) x 13–23 (18) (n=26). Vitellarium follicular, extending anteriorly to posterior margin of nerve commissure, laterally past the lateral nerve chords, extending posteriorly past 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 obovate, 8 wide. Excretory pore subterminal.

Remarks

The new species agrees well with the characters of Braya n. gen. and is here described as a new species in that genus. Braya yantschi n. sp. differs from B. psittacus n. sp. in the combination of straight posterior caeca that extend 31–37% of the body length, a testis that extends laterally to the intercaecal field (on both sides) and has a width 73–94% of the body width and a uterus that extends anteriorly past the posterior margin of the testis. In contrast, Braya psittacus n. sp. has convoluted posterior caeca that extend 47–69% of the body length, a testis that extends laterally to the intercaecal field sinistrally and has a width 52% of the body width and a uterus that is entirely posterior to the testis.

Figures

FIGURES 51–54. Braya yantschi n. sp. from the atrium (heart) of Chlorurus microrhinos off Heron Island. 51. Adult, whole mount, ventral view. Specimen rolled ventrally sinistrally, anteriorly and posteriorly. Although broken anterior to intestinal bifurcation major morphological components undamaged. 52. 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. 53. Male terminal genitalia, ventral view. Posterior margin of worm rolled ventrally. 54. 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: 51, 250 m; 52–54, 200 m.