Pseudorhabdosynochus malabaricus Justine & Sigura, 2007, n. sp.
Creators: name: Justine, Jean-Lou
name: Sigura, Aude
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Monogenea
Dactylogyridea
Diplectanidae
Pseudorhabdosynochus
Pseudorhabdosynochus malabaricus

description: Pseudorhabdosynochus malabaricus n. sp.
(Figs 6–8)
Type host: Epinephelus malabaricus Bloch & Schneider (Serranidae).
Type locality: Lagoon off Nouméa, New Caledonia.
Site: Between secondary gill lamellae.
Type specimens: Holotype, JNC 1536A107, off Ouen Toro, Nouméa, New Caledonia (22°19'S, 166°27'E, 18.v.2005).
Material examined: 9 specimens: 8 ‘carmine’ (c), 1 ‘picrate’ (p), all from JNC 1536.
Material deposited: Holotype (c) and 6 paratypes (5 c, 1 p), MNHN; 1 paratype (c), BMNH 2007.6.1.4; 1 paratype (c), USNPC 99869.
Prevalence: 50% (1/2).
Intensity: See Table 1. A rare species (5% of the diplectanids).
Etymology: From the host name.
Description: Body very wide; length h 630, c 543 (450–650, n = 7), width h 390, c 317 (240–410, n = 7). Tegument scaly; posterior region with scales on ventral and dorsal faces from squamodiscs to level of ovary and testis. Anterior region with 3 pairs of head organs and 2 pairs of eye-spots; distance between outer margins of anterior eye-spot pair h 51, c 43 (37–51, n = 8), of posterior eye-spot pair h 44, c 40 (29–50, n = 8).
Haptor differentiated from rest of body, wider than body, width h 390, c 331 (270–420, n = 7), provided with 2 similar squamodiscs, 2 pairs of lateral hamuli, 3 bars and 14 marginal hooklets. Squamodiscs round in shape, made up of rows of rodlets; central row often dislocated; central rows forming almost closed ovals; rodlets adjacent and of similar width in all rows except last row with very thin, separated rodlets; ventral and dorsal squamodiscs similar, but ventral slightly larger; ventral squamodisc length c 63 (54–69, n = 6), width c 77 (74–79, n = 6), with 11–12 (n = 6) rows of rodlets and 1–2 closed ovals, total number of rodlets h 147; dorsal squamodisc, length h 65, c 64 (59–68, n = 6), width 79, c 71 (68–79, n = 6), with 10–12 (n = 6) rows of rodlets and 0–1 closed oval, total number of rodlets h 133. Ventral hamulus with thick handle and distinct guard, outer length h 62, c 58 (53–63, n = 13), p 61 (n = 2), inner length h 42, c 42 (39–45, n = 14), p 42 (n = 2). Dorsal hamulus with indistinct guard, outer length h 48, c 48 (45–50, n = 16), p 49 (n = 2), inner length h 31, c 30 (27–32, n = 16), p 29 (n = 2). Dorsal (lateral) bars straight, with flattened medial extremity and thick cylindrical lateral extremity, length h 118, c 113 (103–124, n = 15), p 128 (n = 2), maximum width h 23, c 24 (19–31, n = 15), p 26 (n = 2). Ventral bar flat, with slightly constricted median portion and pointed extremities, length h 140, c 132 (92–156, n = 7), p 150, maximum width h 17, c 17 (14–19, n = 7), p 20; groove visible on its ventral side.
Pharynx subspherical, length h 53, c 52 (43–75, n = 8), width h 54, c 49 (42–60, n = 8). Oesophagus apparently absent, such that intestinal bifurcation immediately follows pharynx. Caeca simple, terminate blindly at level of posterior margin of vitelline field.
Testis subspherical, intercaecal, length h 110, c 101 (83–110, n = 3), width h 110, c 90 (80–110, n = 3). Vas deferens emerges from antero-sinistral part of testis, enlarges into seminal vesicle; seminal vesicle in middle region of body, coiled, transforms into duct; duct forms bends then connects with quadriloculate organ; terminal portion of duct enlarged. Prostatic reservoir connects with quadriloculate organ. Quadriloculate organ with fourth (posterior) chamber slightly more sclerotised than 3 anterior chambers; first chamber with very thin anterior wall; fourth chamber ends in short sclerotised cone, prolonged by sclerotised tube; end of tube prolonged by thin unsclerotised filament of variable length. Inner length of quadriloculate organ h 57, c 52 (45–57, n = 7), p 75; cone length h 11, c 11 (10–11, n = 8), p 11; tube length h 15, c 16 (15–18, n = 8), p 16; tube diameter h 3, c 3 (n = 8), p 3; filament length h 4, c 0–19 (n = 8), p 5.
Ovary subequatorial, intercaecal, pre-testicular, encircles right caecum. Ovary width h 100, c 92 (74–114, n = 4). Oviduct passes medially to form oötype, surrounded by Mehlis’ gland; oötype short, opens into uterus. Uterus dextral. Unsclerotised vagina inconspicuous. Duct from sclerotised vagina to oötype inconspicuous. Vitelline fields extend posteriorly from posterior to pharyngeal level in 2 lateral bands, confluent in post-testicular region and terminate anterior to peduncle. Bilateral connections from vitelline fields to oötype inconspicuous. Egg in utero oval, 115–124 × 56–65 (n = 2), with wall thicker at one extremity suggesting presence of filament in mature egg.
Sclerotised vagina (nomenclature of parts according to Justine 2007a; see Figure 20). Sinistral, a complex sclerotised structure; aspect changes according to specimen and orientation (Figure 7). Sclerotised vagina comprises anterior trumpet, followed by primary canal, big spherical primary chamber and small spherical secondary chamber; primary canal tubular, with posterior region slightly thinner than anterior region; primary canal with one coil (or bend) at midlength; primary canal connects to primary chamber on its ventral side; connection is oblique within wall (Figure 7 E); primary chamber spherical with heavily sclerotised wall; internal wall, inserted laterally, visible in certain specimens (Figure 7 C,F); secondary chamber ventral and adjacent to primary chamber, resulting in very short secondary canal; secondary chamber spherical, with wall less sclerotised than primary chamber; accessory structure, weakly sclerotised, ventral, connected to secondary chamber and directed anteriorly; total length of sclerotised vagina (measured from extremity of trumpet to posterior extremity, i.e. not taking in account curved length along bend and coil of canal) h 38, c 38 (34–44, n = 8), p 38; primary chamber external width h 13, c 13 (12–14, n = 8), p 16; primary chamber internal width h 9, c 9 (8–10, n = 8), p 12; secondary chamber external width h 8, c 8 (7–8, n = 8), p 9; primary chamber internal width h 5, c 5 (5–6, n = 8), p 6. Orientation of sclerotised vagina: trumpet always anterior. Differential diagnosis. See after P. m a t e r n u s n. sp.
description: Published as part of Justine, Jean-Lou & Sigura, Aude, 2007, Monogeneans of the malabar grouper Epinephelus malabaricus (Perciformes, Serranidae) off New Caledonia, with a description of six new species of Pseudorhabdosynochus (Monogenea: Diplectanidae), pp. 1-44 in Zootaxa 1543 on pages 11-14, DOI: 10.5281/zenodo.177917