Ligophorus pilengas Sarabeev et Balbuena, 2004 parasite in collection sequenced outlined

Type host

Planiliza haematocheila (Temminck & Schlegel, 1845)

Type locality

Sea of Azov, Utlyukskiy Estuary

Other localities

Black Sea, Sevastopol; Black Sea, Balaklava Bay; Black Sea, Kerch channel (Naberezhnoe); Black Sea, Karantinnaya Bay, Sevastopol

Short description:

General internal morphology and haptoral armaments all conform to diagnose of genus Ligophorus sensu Euzet & Suriano (1977). Flattened specimens with body-size 572–1000 × 90–180 mkm. Anchors similar: distal part shorter than proximal part; distal and proximal parts form obtuse angle; distal part with straightened shaft; point almost at right angle. Ventral anchor roots of almost equal length (inner 10–13, outer 8–11 mkm); inner root of dorsal anchor longer than outer (16–20 vs. 6–12 mkm). Proximal part of the ventral anchors at the point where the roots bifurcate has high individual variability in the shape, sometimes with deep fissure between roots. Ventral anchor: inner length 38–44; distal part length 23–25; shaft length 21–24; point length 9–10; inner length of proximal part 30–33; outer length of proximal part 21–23; span between roots 18–20 mkm. Dorsal anchor: inner length 40–42; distal part length 21–23; shaft length 19–21; point length 9-10; inner length of proximal part 27–30; outer length of proximal part 21–23; span between roots 17–20 mkm. Marginal hooks typical for genus (Euzet & Suriano, 1977): total length 12–13, shaft length 6–7, sickle length 5–6 mkm. Dorsal bar, 5–8 high, 40–46 wide, scale-beam shaped, usually curved. Ventral bar, 8–10 high, 44–51 wide, with two digitiform anterior processes, 5–6 long, span between them 7–9; middle part slightly protruded anterior; ventral side of ventral bar with 2 wide, wing-shaped laminae attached to each anterior process and entirely surrounding lateral margins of ventral median knoll.
Copulatory organ consists of copulatory tube, 108–120 long, 2 mkm wide; expanded base double-chambered, receives the seminal and prostatic reservoir ducts. Accessory piece, 32–40 long, 3–4 mkm wide, not articulated with tube, forms deep gutter, with U-shaped cross-section partly enclosing copulatory tube, bifurcates into 2 parts 2/3 of distance from its distal end. Lower bifurcation is thinner and rather longer than upper (8–12 vs. 7–11 mkm) and slightly deflected (span between bifurcations 1–4 mkm). Upper bifurcation connects with tegument around male genital pore by crimped ligament. Two proximally directional rod-shaped processes beginning from upper bifurcation serve for the insertion of the distal end of the muscular sheath surrounding copulatory tube up to its distal expansion. Vaginal armament is typical for genus, forming hollow, narrow tube with solid walls, 45–75 mkm long.

Nucleotide sequences

Outlines of haptor structures

Dorsal anchors

Dorsal bars

Ventral anchors

Ventral bars

Specimens in collection