Procyrnea excisiformis ( Yamaguti, 1935 )

Zhang, Shuqian, Song, Jie & Zhang, Luping, 2011, Three species of Procyrnea Chabaud, 1958 (Nematoda: Habronematoidea: Habronematidae) from raptors in Beijing, China, with descriptions of two new species, Journal of Natural History 45 (47 - 48), pp. 2915-2928 : 2923-2927

Procyrnea excisiformis ( Yamaguti, 1935)

( Figures 5 and 6 )

F H I J

Host

Asio otus (Linnaeus) .

Locality

Beijing, China (39 ◦ 54’ N, 116 ◦ 28’ E) .

Site of infection

Under the lining of the gizzard.

Prevalence

This was 11.1% (three of 27 birds), 30 specimens.

Voucher specimens

Ten males (HBNU-1124); 10 females (HBNU-1125).

Diagnosis

Body medium size with distinct transverse striations. Labial region consisting of two pseudolabia and dorsal and ventral labia. Pseudolabia wider distally than at base, amphids located on bases of pseudolabia, three small teeth on interior border of pseudolabia, each tooth with an indentation on anterior edge. Dorsal and ventral labia each consisting of two submedian lobes, with two papillae on each, and one median internal process. Lateral alae absent. Anterior part of body with serrated structure on surface. Buccal capsule laterally compressed. Oesophagus clearly divided into short anterior muscular part and long posterior glandular part. Muscular part 3.2–4.0% (3.7%) TBL in male; glandular part 26.0–33.3% (28.6%) TBL in male. Nerve ring located at posterior part of muscular oesophagus. Cervical papillae anterior to nerve ring. Excretory pore posterior to nerve ring.

Male (n = 6). Body length 7.4–9.3 (8.5) mm. Maximum width 330–408 (362). Buccal capsule 21–28 (25) long. Muscular oesophagus 291–358 (316) long and 49–58 (50) wide; glandular oesophagus 2.3–2.9 (2.4) mm long and 136–172 (149) wide. Nerve ring 184–206 (198) from anterior end; excretory pore 223–254 (237) from anterior end; cervical papillae 106–151 (137) from anterior end. Posterior end of body curved ventrally. Caudal alae well developed and symmetrical, 0.69–1.02 (0.85) mm long. Caudal alae with longitudinal striations on ventral surface and transverse striations on dorsal surface. Ventral surface of caudal region with prominent longitudinal ridges. Tail with rounded tip, 194–213 (200) long, with four pairs of symmetrically arranged pedunculate pre-cloacal papillae, two pairs of symmetrically arranged pedunculate post-cloacal papillae, and one single pedunculate papilla located anterior to cloaca. There are 10 sessile papillae located near the tail tip. Spicules unequal and dissimilar. Left spicule 1.0–1.2 (1.1) mm long, with two barbs on distal end. Right spicule 333–408 (360) long, its distal end slightly bent on ventral side. Ratio of right spicule: left spicule 1: 2.9–3.2 (3.0). Gubernaculum present, trowel shaped, 60–72 (66) long and 48–60 (55) wide.

Female (n = 5). Body length 10.3–13.0 (11.2) mm. Maximum width 368–490 (426). Buccal capsule 22–29 (26) long and 17–24 (21) wide. Muscular oesophagus 245–333 (280) long and 29–39 (33) wide; glandular oesophagus 2.7–3.2 (2.9) mm long and 137–172 (152) wide. Nerve ring 196–221 (203) from anterior end; excretory pore 221–255 (233) from anterior end; cervical papillae 108–123 (114) from anterior end. Vulva located 4.1–5.9 (4.7) mm from posterior end. Tail rounded, 220–230 (225) long. Eggs ellipsoid, thick shelled, embryonated, 39–46 (43) long, 24–27(25) wide.

Remarks

Yamaguti (1935) described Cyrnea excisiformis from Asio otus otus in Japan. In his original description, he described a barb on the distal end of the left spicule. However, in our materials, we observed two barbs rather than one barb on the distal end of the left spicule, which was confirmed by scanning electron microscope observations (see Figures 5H and 6F ). However, the other major characteristics including body length, cephalic structure, position of vulva, spicule length, and number of papillae is very close to P. excisiformis . Therefore, we considered our specimens to belong to P. excisiformis ( Yamaguti, 1935) , and the original description of structure of the left spicule may be a mistake.

Chabaud (1958) proposed the subgenus Procyrnea under the genus Cyrnea , and placed this species in this subgenus. He subsequently raised Procyrnea to generic rank ( Chabaud 1975). However, Yamaguti (1961) moved P. excisiformis to the genus Excisa . According to the CIH Keys to the Nematode Parasites of Vertebrates (see Chabaud 1975), the genus Excisa is distinguished by having three large interlocking teeth on each lip. The present scanning electron micrographs clearly showed that this species belongs in the genus Procyrnea as proposed by Chabaud (1958).

Figures

Figure 5. Procyrnea excisiformis (Yamaguti, 1935). (A) Anterior end of male, ventral view; (B, C) anterior end of male, lateral view; (D) vulval region of female, lateral view; (E) posterior end of female, lateral view; (F) posterior end of male, lateral view; (G) gubernaculum, ventral view; (H) distal end of left spicule; (I) distal end of right spicule; (J) posterior end of male, ventral view.

Figure 6. Scanning electron micrographs of Procynea excisiformis (Yamaguti, 1935). (A) Cephalic end of female, apical view; (B) cephalic end of female, ventral view; (C) anterior end of female, ventral view; (D, E) posterior end of male; (F) distal end of left spicule; (G) tip of male tail; (H, I) posterior end of female.