Identification and Prevalence of Globocephalus samoensis (Nematoda: Ancylostomatidae) among Wild Boars (Sus scrofa coreanus) from Southwestern Regions of Korea

Abstract

This study describes the first record of Globocephalus samoensis (Nematoda: Ancylostomatidae) recovered in wild boars from southwestern regions of Korea. Gastrointestinal tracts of 111 Korean wild boars (Sus scrofa coreanus) hunted from mountains in Suncheon-si, Gwangyang-si, and Boseong-gun between 2009 and 2012 were examined for their visceral helminths. G. samoensis, as identified by morphological characteristics of the head and tail, were recovered from the small intestine of 51 (45.9%) wild boars. Worms were found from 7 of 28 wild boars (25.0%) from Suncheon-si, 40 of 79 (50.6%) from Gwangyang-si, and all 4 (100%) from Boseong-gun. The length of adult females was 7.2±0.5 mm, and the thickest part of the body measured the average 0.47±0.03 mm, while those of males were 6.52±0.19 and 0.37±0.02 mm, respectively. The buccal cavity was equipped with a pair of large and bicuspid subventral lancets near the base of the capsule. The average length of spicules of males was 0.45±0.02 mm. By the present study, G. samoensis is recorded for the first time in southwestern regions of Korea. Additionally, morphological characteristics and identification keys provided in the present study will be helpful in the faunistic and taxonomic studies for strongylid nematodes in both domestic and wild pigs. The infection of G. samoensis apparently did not elicit pathologic lesions, as revealed by macroscopic observation during the autopsy of all wild boars in this study.

Keywords: Globocephalus samoensis; Korea; nematode; prevalence; wild boar.

Fig. 1.

Light micrographs of Globocephalus samoensis isolated from the small intestine of Korean wild boars (Sus scrofa coreanus) from South Korea. (A) Whole body view of an adult male. (B) Whole body view of an adult female. (C) Lateral view of the anterior end of a male, showing the buccal cavity (BCV), buccal capsule (BCP), and bicuspid lancets (L). (D) Lateral view of the middle body of female, showing the vulva (V). (E) Lateral view of the posterior end of a female, showing the anus (A) and spike (S). (F) Bursa of a male, showing the dorsal ray (DR). (G) An egg of G. samoensis. (H) Lateral view of the posterior end of a male, showing the 2 spicules (Sp) and gubernaculum (G). Bars=100 μm, except for A and B.

Fig. 2.

Scanning electron micrographs of Globocephalus samoensis isolated from the small intestine of a Korean wild boar (Sus scrofa coreanus) from South Korea. (A) Anterior end of a female, illustrating 1 of the 2 cervical papillae (white arrow) and an excretory pore (white arrow head). (B) Enlarged enface view of the anterior end showing the 2 bicuspid lancets (white arrow). (C) Enlarged view of the cervical papillae. (D) Enlarged view of the vulva. (E) Posterior end of female, showing the anus (white arrow). (F) Enface posterior end of a male, showing the copulatory bursa.

Fig. 3.

Identification key to the closely related genera of the superfamily Ancylostomatoidea (redrawn after Anderson, 2009).

Fig. 4.

Identification key to the closely related specises of Globocephalus from pigs and geographical distribution.