Aonchotheca pulchra (Freitas), 2014

Aonchotheca pulchra (Freitas) View in CoL

Infection site: stomach and intestine

Localities: Calcehtok and Homún

Prevalence (%) and mean intensity: Calcehtok 59.5 and 2.8 (2.4‒3.4). Homún 41.4 and 2.1 (1.5‒3.2)

Specimens deposited: CNHE-12315 and NHM 2025.8.13.8

GenBank accession number: PX232600 (28S)

Comments: Based on six males and seven females. Two wide lateral bacillary bands, composed of numerous hypodermal round cells. Stichocytes arranged in a single row and subdivided into several transverse annuli with large nuclei. Two mesenchymal cells observed at the esophago-intestinal junction. Male body length 13448 ± 1994 (10650‒15720) and maximum body width 85 ± 12 (70‒100). Total esophagus length 4833 ± 722 (4100‒5740); muscular esophagus length 432 ± 93 (330‒519), stichosome length 5095 ± 308 (4751‒5332). Posterior body region 8520 ± 1443 (6550‒10470) long. Ratio between anterior esophageal region and posterior intestinal region 0.6 ± 0.1 (0.5‒0.6). Two caudal lateral alae, and a relatively small, caudal membrane supported by two lateral expansions (or rays), which end in papillae on posterior extremity of body. Ventrally, two digitiform expansions observed, each with two short projections arising from their base, ending in terminal papillae. Another pair of papillae on the sides of the cloaca, between the base of the caudal membrane and the posterior edge of the latero-caudal alae. Spicule indistinct due to little or no sclerotization. The rugged non-spiny spicular sheath generally protruded outside the body and curled ( Figure 5A View FIGURE 5 ). Female body length 14090 ± 3165 (10105‒18555) and maximum body width 173 ± 26 (140‒207). Total esophagus length 4927 ± 1182 (3820‒7108); muscular esophagus length 516 ± 94 (376‒605), and stichosome length 4894 ± 1236 (4037‒6732). Posterior body region 8842 ± 2711 (6285‒13775) in length. Vulva at 3387 ± 1058 (2320‒4350) from anterior extremity. Vulvar membranous appendage present ( Figure 5B View FIGURE 5 ). Conical tail, slightly curved ventrally with subterminal anus. Eggs 44 ± 1 (42‒45) × 26 ± 3 (24‒30). Ratio between anterior esophageal region and posterior intestinal region 0.6 ± 0.1 (0.4‒0.7).

The morphology and morphometric data of the Yucatán specimens fit the redescription of A. pulchra by Cardia et al. (2014). This is the first record of A. pulchra in Mexico.