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''Pseudorhabdosynochus justinella'' is a diplectanid monogenean parasitic on the gills of the red grouper, ''Epinephelus morio''. It as been described by Kritsky, Bakenhaster and Adams in 2015. 〔 〕 ==Description== ''Pseudorhabdosynochus justinella'' is a small monogenean. The species has the general characteristics of other species of ''Pseudorhabdosynochus'', with a flat body and a posterior haptor, which is the organ by which the monogenean attaches itself to the gill of is host. The haptor bears two squamodiscs, one ventral and one dorsal. The sclerotized male copulatory organ, or "quadriloculate organ", has the shape of a bean with four internal chambers, as in other species of ''Pseudorhabdosynochus''.〔Kritsky, D. C. & Beverley-Burton, M. 1986: The status of ''Pseudorhabdosynochus'' Yamaguti, 1958, and ''Cycloplectanum'' Oliver, 1968 (Monogenea: Diplectanidae). Proceedings of the Biological Society of Washington, 99, 17-20. (PDF ) 〕 The vagina includes a sclerotized part, which is a complex structure. The description by Kritsky, Bakenhaster & Adams in 2015 includes the following: Body fusiform, dorsoventrally flattened, with a slight constriction at level of male copulatory organ (MCO); peduncle with small tegumental scales having rounded anterior margins. Cephalic region broad, with two terminal and two bilateral poorly developed lobes, three bilateral pairs of head organs, two bilateral groups of cephalic-gland cells at level of pharynx. Four eyespots lacking lenses immediately anterior to pharynx; members of posterior pair larger, slightly closer together than those of anterior pair; accessory chromatic granules small, irregular in outline, uncommon in cephalic region. Pharynx ovate to subspherical, muscular; esophagus short to nonexistent; intestinal ceca blind, extending posteriorly to level of peduncle, with ends slightly diverging. Peduncle broad, tapered posteriorly. Haptor subtrapezoidal, with dorsal and ventral anteromedial lobes containing respective squamodiscs and lateral lobes having hook pairs 2–4, 6, 7. Dorsal and ventral squamodiscs similar, subequal, each with 10–12 (usually 11) U-shaped rows of rodlets; innermost row usually closed. Ventral anchor with elongate superficial root, slightly shorter deep root having lateral swelling, slightly curved shaft, and moderately long recurved point extending just past level of tip of superficial root. Dorsal anchor with subtriangular base, poorly defined superficial root, elongate deep root, arcing shaft, recurved point extending past level of tip of superficial root. Ventral bar robust, with medial constriction, tapered ends, longitudinal medioventral groove. Paired dorsal bar with spatulate medial end. Hook with elongate slightly depressed thumb, delicate point, uniform shank; FH loop nearly shank length. Testis subspherical, lying sinistroposterior to germarium; proximal vas deferens not observed. Seminal vesicle a fusiform dilation of distal vas deferens, lying just posterior to MCO; ejaculatory bulb pyriform; large vesicle (prostatic reservoir?) lying to right of MCO. MCO reniform, quadriloculate, with short tapered cone, distal tube with delicate wall continuous with distal filament; distal filament with bulbous end; walls of chambers comparatively delicate, often collapsed. Germarium pyriform, lying at midlength of trunk, with dorsoventral distal loop around right intestinal cecum; ootype lying slightly to left of body midline and surrounded by well-developed Mehlis’ gland; uterus banana-shaped when empty, delicate. Common genital pore ventral, dextral to distal chamber of MCO. Vaginal pore sinistroventral at level of seminal vesicle; vaginal vestibule with delicate wall; vaginal sclerite with small distal funnel, sigmoid tube leading to thick-walled ovate to subspherical chamber; proximal vaginal canal arising from chamber, extending to subovate seminal receptacle near body midline immediately anterior to ootype and Mehlis’ gland. Bilateral and common vitelline ducts not observed; vitellarium dense, absent in regions of other reproductive organs, otherwise extending in bilateral fields of trunk from level of MCO to anterior limit of peduncle; bilateral fields confluent posterior to testis. Egg ovate (often collapsed due to staining and mounting procedures), lacking filaments. Measurements: Body 511 µm (420–661; n = 28) long, width at level of germarium 157 µm (114–202; n = 30). Haptor 152 µm (131–176;n = 27) wide; squamodisc 55 µm(43–61; n = 41) long, 68 µm (57–76; n = 42) wide. Ventral anchor 39 µm (36–42; n = 15) long; dorsal anchor 36 µm (34–38; n = 17) long. Ventral bar 67 µm (63–77; n = 14) long; dorsal bar 55 µm (51–59; n = 16) long. Hook 11–12 µm (n = 21) long. Pharynx 34 µm (29–43; n = 29) wide. MCO 62 µm (56–68; n = 28) long. Testis 64 µm (51–82; n = 22) long, 65 µm (50–77;n = 22) wide. Germarial bulb 34 µm (26–43; n = 19) wide. Egg 118–119 µm (n = 1) long, 54–55 µm (n = 1) wide.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pseudorhabdosynochus justinella」の詳細全文を読む スポンサード リンク
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