Cystoopsis acipenseris Wagner 1867

Cystoopsis acipenseris Wagner, 1867

Description (after Moravec 2001). Head rounded in both sexes. Mouth opening triangular, surrounded by ring mound with 10 small teeth. Four small cephalic papillae, and pair of lateral amphids. Anterior muscular portion of oesophagus well developed, posterior glandular portion comprising two longitudinal rows of stichocytes (Fig. 17 A). Intestine in both sexes ends blindly.

Males: body cylindrical, both ends rounded, 2.10 – 3.00 long, 0.017 – 0.024 wide. Cuticle with fine cuticular tubercles. Muscular oesophagus 0.27 – 0.28 long, glandular one 0.70 – 0.73 long. Nerve ring encircles muscular oesophagus slightly behind its proximal end. Testis convoluted, filling entire body-cavity. Spicule fine, moderately sclerotized, 0.23 – 0.26 long. Spicular sheath present (Fig. 17 B).

Females: anterior body region thread-like 2.48 – 2.74 long, posterior globular region 5.0 – 6.0 in diameter (Fig. 17 C). Anterior cuticle with transverse rings of minute tubercles. Muscular oesophagus 0.54 – 0.57 long, glandular one 1.09 – 1.18 long. Oesophago-intestinal junction in anterior body region. Intestine continues into posterior globular region ending blindly as a sac 2.0 – 2.5 wide. Nerve ring 0.48 – 0.52 from anterior end. Vulva 0.080 – 0.120 from anterior end (Fig.17 A). Muscular vagina passes through thread-like body region. Uterine coils, ovary and oesophagus fill body-cavity in posterior body region. Uterus contains many eggs at different stages of development, mature ones containing formed larvae. Mature eggs thin-walled with smooth surface, barrel-shaped with polar plugs, 0.063 – 0.068 x 0.021 – 0.025 (Fig. 17 D).

Site: subcutaneous

Host: Acipenser transmontanus (1, 2)

Distribution: British Columbia

Records: 1. Margolis & McDonald 1986; 2. McDonald et al. 1989