Description

DESCRIPTION General: (based on 9 males and 4 females) Relatively small robust worms, trunk more of less cylindrical, body wall thick, aspinose (Figs 18, 22). Main lacunar canals with regular lateral branches. Proboscis conical, truncated, in 2 parts; anterior proboscis with rooted hooks, posterior proboscis wider with spines (Fig. 20); Roots of hooks flask shaped with rounded larger posterior ends with scalloped edges, anterior spines with much reduced flask shaped roots, posterior spines with basal discs (Fig. 19). Proboscis armature similar in both sexes, 18 - 22 rows of 4 - 5 hooks, about same number of irregular rows 2 - 3, usually 2 spines; male, longest hooks 20, 21, 22, shortest hooks 15, 15, 19; spines 5, 10 long. Neck unarmed, conical, widest at junction with broader trunk. Proboscis receptacle attached anteriorly at junction between anterior and posterior proboscis, with cerebral ganglion near mid region (Fig. 24). Lemnisci long, slender, equal, inserted at base of neck, extend beyond anterior testis in male (Fig. 18). Genital pore, male and female, terminal. Male: (Based on 9 specimens) Trunk 4 - 7 (4.9) mm long 440 - 970 (650) wide. Proboscis 265 - 535 (424) long, 230 - 605 (347) wide; anterior proboscis 160 - 385 (247), posterior proboscis 95 - 150 (129). Neck 20 - 200 (126) long, 230 - 770 (443) wide. Proboscis receptacle 350 - 680 (504) long, 135 - 235 (187) wide. Lemnisci 1535 - 3145 (2150) long, 80 - 150 (112.9) wide. Testes ovoid, tandem, usually contiguous, in mid third of trunk; anterior testis 850 - 1190 (1059) long, 180 - 610 (322) wide; posterior testis 765 - 1375 (1080) long, 180 - 680 (368) wide. Cement glands 8 globular, in cluster, 175 - 460 (279) in diameter. Saefftigen’s pouch 375 - 690 (500) long (Fig. 23). Female: (based on 4 specimens, none with proboscis fully extended) Trunk 15 - 22 (18.5) mm long, 765 - 1020 (850) wide. Proboscis 360 - 535 (448) wide; lengths of anterior and posterior proboscis not determined. Neck 85 - 135 (110) long, 435 - 440 (438) wide. Proboscis receptacle 500 - 800 (650) long, 265 - 295 (285) wide. Lemnisci 2940 - 3095 (3018) long, 150 wide. Reproductive tract, 300 - 650 (484) long, about 20 - 29.5 % of trunk length (Fig. 21). Eggs not seen. Cystacanth: (single specimen) proboscis 330 long, 247.5 wide; anterior proboscis 220, posterior proboscis 110 long.

Common Names

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Acanthocephala

Class: Archiacanthocephala

Order: Gigantorhynchida

Family: Giganthorhynchidae

Genus: Mediorhynchus

Species: Mediorhynchus ayeri Smales, 2014