Affecauda rugosa, Hall, Kathryn A. & Cribb, Thomas H., 2004

Hall, Kathryn A. & Cribb, Thomas H., 2004, Revision of Affecauda Hall & Chambers, 1999 (Digenea: Gyliauchenidae Fukui, 1929), including the description of two new species from fishes of the Indo­West Pacific, Zootaxa 778, pp. 1-12 : 3-6

Affecauda rugosa n. sp. ( Fig. 1 )

Type­host: Zebrasoma veliferum (Bloch, 1797) , Acanthuridae ; sailfin tang.

Site: intestine.

Type­locality: Noumea, New Caledonia (21°30'S 165°30'E, 22 Nov. 1997).

Prevalence: 2 of 3 (66.7%).

Intensity: 0.66.

Deposition of specimens: holotype QM G222106.

Etymology: This species is named from the Latin rugosus (= wrinkled) and refers to the presence of tegumental annulations along most of the body, which gives the appearance of wrinkles.

Description: Based on 2 whole­mount preparations of 1 mature, complete worm and 1 immature, fractured worm. Measurements in Table 1 . Body elongate, extremely slender for entire length, rounded at ends, pronounced curvature dorsoventrally ( Figure 1 ); pale creamy­yellow in life. Tegument distinctly annulated from level of oesophagus to immediately anterior to ventral sucker. Ventral sucker longitudinally elongate, at posterior extremity of body; peduncle inconspicuous. Pharynx elongate, barrel­shaped, subterminal, surrounds mouth. Oesophagus long, sigmoid, with single loop, posterior chamber developed, invested with glands along entire length; lining thick. Oesophageal bulb smaller than pharynx, ovoid, discrete. Caeca of equal lengths, terminate posterior to level of genital aperture.

A. rugosa A. salacia

n = 1 n = 4

Feature Measurement Mean Min Max body length 1456 1504 1456 1536 ratio of oesophageal bulb to ventral sucker (length) 0.28 0.64 0.67 0.60 ratio of oesophagus to body (length) 0.28 0.50 0.51 0.49 ratio of caeca to body (length) 0.26 0.16 0.15 0.17

Testes 2, entire, ovoid, tandem, contiguous, in posterior third of body. Vasa efferentia not observed. Cirrus­sac present, spherical, ventral to caeca, encased in muscular capsule contiguous with pars prostatica and anterior portion of seminal vesicle. Seminal vesicle external, unipartite, frequently obscured by uterus. Pars prostatica large, cylindrical, tapering anteriorly, thickly surrounded by prostate gland cells, which partially penetrate cirrus­sac. Ejaculatory duct short, simple, expanding distally; everted cirrus not observed. Genital atrium large, convoluted. Genital pore irregularly elliptical, median, ventral to caeca.

Ovary ovoid, pretesticular, sinistral, overlapping anterior testis; oviduct associated with swollen insemination chamber. Seminal receptacle canalicular, globular, dorsal to ovary. Ootype anterior to ovary. Mehlis’ gland not observed. Laurer’s canal proceeds posterodorsally, opening dorsal to ovary. Vitellarium follicular; follicles largely restricted to anterior half of body, extend from posterior margin of pharynx to anterior margin of ovary; dorsal, ventral and lateral fields confluent. Vitelline reservoir globular, posterior to ovary. Uterus entirely pre­ovarian. Eggs unembryonated in utero; opercula not observed. Opening of uterus unspecialised, enters genital atrium sinistral to cirrus­sac.

Excretory vesicle saccular; lining not observed; pore opens on small, but distinct dorsosubterminal papilla. Primary collecting ducts arise anterolaterally; 1 pair only. Lymphatic system not observed.

Comments: Affecauda rugosa is immediately distinguished from the type­species, A. annulata , by the difference in the posterior body shape. Specimens of A. annulata have a distinctively elongate, extremely narrow body posterior to the gonads, at the terminus of which is the ventral sucker; this condition is not seen in A. rugosa . Further, the annulations on the tegument of A. rugosa are more extensive than those of A. annulata , commencing immediately posterior to the level of the pharynx and terminating immediately anterior to the ventral sucker on the ventral surface and immediately anterior to the excretory pore on the dorsum. The seminal vesicle of A. rugosa is unipartite, rather than bipartite, and the ovary is pretesticular and sinistral to the midline, in contrast to the intertesticular position in A. annulata . This combination of morphological features makes A. rugosa clearly distinct from A. annulata .

Although only 1 mature specimen of this species has been recovered, the condition of this specimen is excellent and it is gravid. The morphology of this specimen is clearly different from that of A. annulata , and accordingly we believe that this new species description is justified. The collection of additional material for incorporation into this description is highly desirable, as is the fixation of material in ethanol for use in DNAbased studies.

Figures

FIGURE 1. Affecauda rugosa n. sp. from the intestine of Zebrasoma veliferum. Lateral view of holotype. Scale bar = 500 µm.

Tables

TABLE 1. Measurements of Affecauda rugosa n. sp and Affecauda salacia n. sp. All measurements are presented in micrometres (µm). Ratios calculated to 2 decimal places.

body width	192	299 272 320
pharynx length	154	135 128 141
pharynx width	90	135 122 148
oesophageal bulb length	58	116 116 116
oesophageal bulb width	90	137 122 148
ventral sucker length	205	182 173 193
ventral sucker width	128	150 141 161
oesophagus length	408	748 748 748
caeca length	385	242 218 263
length from pharynx to oesophageal bulb	231	227 225 231
length from oesophageal bulb to ventral sucker	931	873 815 950
anterior testis length	128	161 128 193
anterior testis width	109	138 122 154
posterior testis length	141	148 128 167
posterior testis width	103	119 109 128
ovary length	90	66 64 71
ovary width	83	66 64 71
seminal receptacle length seminal receptacle width cirrus length	– – 128	141 141 141 122 122 122 220 199 238
cirrus width	83	128 122 135
egg length	61	70 64 74
egg width	39	43 39 51
excretory papilla length	51	59 51 67
ratio of pharynx to oesophageal bulb (length)	2.66	1.16 1.10 1.22
ratio of pharynx to ventral sucker (length)	0.75	0.74 0.74 0.73