Description

DESCRIPTION General: (based on 2 males, 4 females) Robust worms, medium sized, trunk cylindrical, thick, with shoulders, posterior third expanded in male, slightly tapering at posterior end in female, aspinose (Figs 9, 11). Main lacunar canals with regular lateral branches. Proboscis conical, truncated, in 2 parts; anterior proboscis with rooted hooks, posterior proboscis wider, with spines; hooks and spines embedded in cuticular papillae when proboscis not fully extended. Roots of hooks flask shaped with rounded larger posterior ends, spines slender with either reduced slender flask shaped roots or basal discs. Proboscis armature similar in both sexes, 22 - 24 rows of 5 - 6 hooks, about same number of irregular rows 5 - 6 spines (Fig. 10). Hook lengths, sequence of 2 longitudinal rows measured from anterior, 7 -; 18, 18; 16.5, 16; 22, 12; 13, 12; 13, 8 long; spines 5, 10 long (Figs 13, 14). Neck unarmed, conical, widest at junction with broader trunk. Proboscis receptacle attached anteriorly at junction between anterior and posterior proboscis, about twice as long as proboscis, with cerebral ganglion near mid region (Fig 16). Lemnisci long, slender, equal, inserted at base of neck (Fig. 9). Genital pore, male and female, terminal. Male: (Based on 2 specimens) Trunk 9.1, 11 mm long, 680, 850 wide. Proboscis 470 long, 370 wide; anterior proboscis 290, posterior proboscis 180. Neck 120 long, 300 wide. Proboscis receptacle 850 long, 320 at widest part. Lemnisci 2800 long, 100 wide. Testes ovoid, tandem, contiguous, in posterior third of trunk; anterior testis 680 long, 305 wide; posterior testis 985 long, 440 wide. Cement glands 8 globular, in cluster, each about 100 wide. Saefftigen’s pouch 600 long (Fig. 15). Female: (based on 4 specimens) Trunk 15 - 22 (18.75) mm long, 670 - 1105 (826) wide. Proboscis 415 - 770 (630) long; anterior proboscis 230 - 380 (350) long, posterior proboscis 185 - 385 (373) long; 315 - 375 (337) wide. Neck 105 - 170 (150) long, 370 - 450 (423) wide. Proboscis receptacle 670 - 750 (707) long, 215 - 220 (217) wide. Lemnisci 7500 (1 measurement) long, 110 wide. Reproductive tract, 500, 600 long (Fig. 17). Eggs ovoid, with concentric shells and thin outer membrane; 49.5 - 56.1 (52.8) long, 26.4 - 29.7 (28.0) wide (Fig. 12).

Common Names

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Acanthocephala

Class: Archiacanthocephala

Order: Gigantorhynchida

Family: Giganthorhynchidae

Genus: Mediorhynchus

Species: Mediorhynchus amini Smales, 2014