Braya psittacus, 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 : 50-51

Braya psittacus n. sp.

( Figs 47–50 )

Type host: Scarus ghobban (Forsskål) , Bluebarred 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. ghobban, Heron Island ( QLD), Apr. 2005, Feb. 2005, three specimens (nos. QM G 225248–225250 ) (one specimen destroyed during dissection) (three specimens sequenced for ITS2) .

Locality: 1. Heron Island; 2. Lizard Island; 3. Ningaloo Reef.

Prevalence of infection: Three of six S. ghobban off Heron Island infected with seven specimens .

Collector: M.J. Nolan.

Etymology

Specific name from “ Psittacus ” (L. parrot), for the Australian common name of the hosts from which this genus is so far found.

Description

Based on three whole mounts. With features of genus. Body elliptical, 942–1226 (1105) x 206–458 (309), 2.7–5.6 times longer than wide, widest level with termination of the posterior caeca and testis ( Figure 47 ). Tegumental spine rows 11–32 (21) wide; number of spines per row increasing from anterior and posterior ends toward middle of body, 3–9 anteriorly, 9–11 mid–body, 9–4 posteriorly. Nerve chords conspicuous; nerve commissure 51–86 (69) or 5–7% of body length from anterior end. Oral sucker spherical to ovoid, 26–31 (29) x 21–26 (24), delimited posteriorly by fine membrane ( Figure 48 ). Mouth 10–11 (11) from anterior end. Oesophagus narrow anteriorly and posteriorly, widening medially, surrounded by gland cells from level of posterior margin of nerve commissure to intestinal bifurcation, 563–670 (617) or 55–60% of body length. Intestine X­shaped; anterior caeca unequal, right anterior caecum 180 long, relatively straight by comparison to left anterior caecum, left anterior caecum 130 long, anterior extremity expanded, ventral to oesophagus, length 14% of body length, irregular in outline, ventral to oesophageal gland cells; posterior caeca sinuous, convoluted, unequal, right posterior caecum 600–610 (605) long, left posterior caecum 440–850 (645) long, length 47–69% of body length, 3.4 times longer than anterior pair, posterior extremities expanded. Testis originating in posterior half of the intercaecal field, extending laterally and posteriorly to field sinistrally, irregular in shape, 240 or 20% of body length x 160 or 52% of body width, 1.5 times longer than wide, containing dorso­ventral muscle fibres. Vas deferens originates at the centre of the posterior margin of testis, narrow, passing posteriorly sinuously, expanding distally to form seminal vesicle. Seminal vesicle lanceolate, sinuous, 29–55 (39) or 2–6% of body length from posterior end (taken from point where narrows to thin tube before male genital pore), 90–150 (129) x 20–49 (38), 3.0–4.5 times longer than wide. Male genital pore opening dorso­sinistrally at posterior end of body ( Figure 49 ). Ovary mostly posterior to intercaecal field, irregular in shape, dorsal to termination of right posterior caecum and vas deferens, 52–57 (55) or 5–6% of body length x 68–82 (75) or 15–31% of body width; 187–227 (207) or 19–20% of body length from posterior end. Oviduct originating at centre of posterior margin of ovary, passing posteriorly then anterodextrally, looping dorso­sinistrally, expanding to form oviducal seminal receptacle, narrowing level with posterior narrowing of seminal vesicle, then passing anterosinistrally, joining with vitelline duct lateral to oviducal seminal receptacle and seminal vesicle. Oviducal seminal receptacle elliptical to oblanceolate, 104–147 (127) x 33–42 (37), 3.1–4.0 times longer than wide, dextrally orientated. Vitelline duct seen at intestinal bifurcation, narrow anteriorly, forming circle­like structure posterior to anterior margin of testis, expanding to form vitelline reservoir anterior to posterior margin of testis, posteriorly narrowing again, passing posteriorly ventral to left posterior caecum, testis, vas deferens, ovary and oviducal seminal receptacle, dorsal to distal portion of oviduct. Oötype elliptical to ovoid, antero­sinistrally directed, lateral to posterior margin of seminal vesicle and oviducal seminal receptacle, 37–54 (45) x 26–31 (28). Mehlis’ gland not seen. Uterus sinuous, passing antero­sinistrally from oötype, dorsal to seminal vesicle, then postero­dextrally to joining of oviduct and vitelline duct, level with posterior margin of oviducal seminal receptacle passes anteriorly along midline, dorsal to oviducal seminal receptacle, oviduct, oötype, vitelline duct and vas deferens, at sinistral posterior margin of ovary loops sinistrally across midline posterior to posterior margin of testis to join metraterm. Metraterm muscular, narrow, convoluted proximally, straight distally, 114–143 (129) x 11–13 (12). Female genital pore sinistral, opening posteriorly to female genitalia, antero­sinistrally to male pore ( Figure 50 ). Eggs ovoid, 15–29 (23) x 8–21 (17) (n=20). Vitellarium follicular, extending anteriorly to posterior margin of nerve commissure, laterally past the lateral nerve chords, extending posteriorly past posterior margin of ovary and testis, anteriorly dorsal to lateral nerve chords, both dorsal and ventral to oesophagus, intestine and testis, posteriorly ventral to ovary. Excretory vesicle obovate, 6–16 (10) wide; collecting ducts seen extending anteriorly from anterior margin of vesicle. Excretory pore subterminal.

Figures

FIGURE 47. Braya psittacus n. g., n. sp. from the atrium (heart) of Scarus ghobban off Heron Island. Adult, whole mount, ventral view. Scale­bar: 250 m.

FIGURES 48–50. Braya psittacus n. g., n. sp. 48. A,B. Anterior region, ventral view. Arrow indicates thin septum separating the vestigial oral sucker from body proper. Spines not seen on specimens due to small size of vestigial oral sucker. 49. A,B. Male terminal genitalia, ventral view. Seminal vesicle extends from arrow “a” to arrow “b”. 50. 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: 48A, 49A, 50, 200 m; 48B, 49B, 100 m.