Work

Description of a novel phyllobothriidean cestode from the bull shark Carcharhinus leucas (Valenciennes) from the Persian Gulf

Year: 2026

Type: article

Abstract: Carcharhinus leucas is a shark species with a global distribution mostly in tropical and subtropical waters, including the Persian Gulf. Knowledge of the cestode fauna of this host continues to grow. In the present study, a new species of phyllobothriidean cestode, Scyphophyllidium persicarium n. sp., is described from the spiral intestine of a bull shark collected off Bandar Lengeh in the Persian Gulf, Iran. The new species is assigned to Category 6 of Scyphophyllidium based on the presence of apical suckers on broad bothridia lacking facial and marginal loculi, the absence of bothridial pores, the presence of gongylate columnar spinitriches on the distal bothridial surface and serrate gladiate spinitriches on the proximal bothridial surface, and the presence of scutes on the strobila. Scyphophyllidium persicarium n. sp. can be distinguished from its congeners by a combination of characters, including total length (11.6–22.9 mm), number of proglottids (30–50), number of testes (80–111), and vitelline follicle distribution (mostly 1 column, rarely 2 columns dorsally and ventrally) in two lateral bands. The new species is further characterized by a euapolytic strobila and the absence of a cephalic peduncle. This discovery brings the total number of Scyphophyllidium species known from C . leucas to four and expands the known diversity of the genus in the Persian Gulf to seven. Globally, infection patterns of Scyphophyllidium species in their shark definitive hosts reveal that a single shark species can harbor multiple congeners either sympatrically or allopatrically, with combinations of species from the same or different morphological categories. The evolution of different microthrix forms among Scyphophyllidium species, particularly across categories 5 through 7, is discussed in light of these infection patterns, with host switching, coupled with adaptation to host intestinal anatomy, proposed as a plausible mechanism explaining microthrix diversity within congeners in a single shark host.

Source: International Journal for Parasitology Parasites and Wildlife

DOI: 10.1016/j.ijppaw.2026.101296

Authors: Minoo Mastoori, Mohammad Haseli

Institution: University of Guilan

Language: English

Topic: Parasite Biology and Host Interactions

Subfield: Parasitology

Field: Immunology and Microbiology

Domain: Life Sciences

SDG: Life below water

Open Access status: gold

Estimated APC paid: $1,930