Aptorchis glandularis Tkach et Snyder, 2008

Type host:

Northwestern red-faced turtle, Emydura australis Gray, 1841

Localities

Type locality: Lake Argyle Spillway, Ord River, Western Australia, 16° 07.371'S, 128° 44.271'E

Other localities: Bell Creek, King Leopold Ranges Conservation Reserve, Kimberley Region, Western Australia, 17° 10.159’S, 125° 21.521’E; King River Pool, King River, Kimberley Region, Western Australia 15° 39.770’S, 128° 05.237’E; Miner’s Pool, Drysdale Station, Drysdale River, Kimberley Region, Western Australia, 15° 40.810’S, 126° 24.270’E.

Type specimens:

Holotype: Queensland Museum (QM) no. G228979. Paratypes: QM no. G228980 - 228982; Harold W. Manter Laboratory no. HWML48613 (a lot of three specimens).

GenBank numbers: EU334367, EU334368

Description (from Tkach and Snyder, 2008)

Measurements based on 13 adult specimens, 7 of them from type locality and 6 from 3 other localities; measurements of holotype in text; measurements of entire series used in description in Table I. Body elongate, widest near level of testes; body length 3,913, body width at level of ventral sucker 1,000. Body width 25.6% of body length. Tegument thick, spination heaviest anterior of ventral sucker; spines decrease in size and density as they extend to posterior end and disappear a short distance posterior to level of testes. Ventral surface with 3 rows of glandular protrusions in hindbody. Each row contains 6 glands in the holotype and 6 or 7 glands in other specimens of the type series, total number of glands 18 to 21. Oral sucker rounded, subterminal, 235 long x 360 wide, slightly smaller than rounded ventral sucker, 284 x 297. Ventral sucker situated in anterior half of body at 36.3% of body length, its surface aspinose.

Prepharynx 151 long, widening posteriorly. Muscular pharynx, 185 long x 170 wide. Esophagus 240, surrounded by group of glandular cells. Intestinal bifurcation 776 from anterior end of body. Ceca nearly reach posterior end of body, terminating 128 from end.

Testes 2, opposite, spherical to subspherical, postovarian, ventral to ceca in posterior third of body, closer to posterior body end than to ventral sucker. Left testis 204 long x 194 wide, right testis 204 x 177. Testes intracecal with lateral margins occasionally overlapping ceca. Cirrus sac very large, 1,013 long, tortuous, passing intracecally, dorsal to and within margins of ventral sucker. In some specimens middle part of cirrus sac forms a loop (Fig. 2). Base of cirrus sac well posterior of posterior margin of ventral sucker. Cirrus sac with bipartite internal seminal vesicle, very large pars prostatica. Everted cirrus not observed. Genital pore ventral, submedian, dextral or sinistral, anterior to ventral sucker, 1,136 from anterior end of body.

Ovary spherical, 153 long x 157 wide, situated midway between posterior portion of cirrus sac and anterior margin of testes. Seminal receptacle thick-walled, 119 long x 120 wide, immediately posterior to and slightly overlapping ovary. Vitellarium begins 215 posterior of ventral sucker, consists of small, irregularly shaped follicles, arranged in mostly extracecal lateral fields that merge at posterior end of body forming “U”. Ootype and Mehlis' gland just posterior to ovary and ventral to seminal receptacle. Laurer's canal not visible in total mounts. Uterus ventral to other organs, mostly intra- and post-cecal, with occasional extracecal loops. Metraterm approximately as long as cirrus sac. Metraterm passes dorsal to cirrus sac before opening into genital atrium. Eggs operculate, 28 x 16. Excretory pore dorsal, subterminal; excretory vesicle Y-shaped, reaches the level of ootype.

Illustrations

Aptorchis glandularis. A - Ventral view of holotype not showing ventral glands, B - ventral view of holotype showing arrangement of ventral glands, C - immature specimen showing arrangement of ventral glands, position of excretory pore and shape of excretory vesicle. Scale bars: A, B = 1,000 µm, C = 500 µm.

Authors: Vasyl V. Tkach, Scott D. Snyder, Yuriy Kuzmin