The Identification of Digramma interrupta (Diphyllobothriidae: Ligula) in a Captive Red-Crowned Crane and a Crucian Carp Reveals a New Case for Co-Occurrence.

purposeThis study aims to identify tapeworms found in a captive red-crowned crane (Grus japonensis) and local crucian carp (Carassius carassius) and to investigate their genetic relationships, with a focus on Digramma interrupta.

methodsMolecular analyses, including ITS and cox1 gene sequencing, were conducted to identify the parasite species. Phylogenetic analysis was performed using the ITS2 and cox1 sequences from tapeworms in both hosts.

resultsThe ITS and cox1 sequences from the tapeworms in the red-crowned crane presented greater than 99.5% similarity to those from the crucian carp. Phylogenetic analyses suggest that tapeworm specimens recovered from both hosts likely correspond to the same species, D. interrupta. Our phylogenetic results also provide tentative support for the placement of the genus Digramma within Ligula.

conclusionThis study is the first to report a zoo-captive red-crowned crane likely infected with D. interrupta through the consumption of crucian carp. The overlapping habitats and dietary habits of the crane support the infection of D. interrupta via infected fish. These findings constitute a new documented case of D. interrupta infecting cranes via fish-eating bird infection pathways, supplying fresh evidence to understand its infection and spread, offering valuable insights for the monitoring, diagnosis, and prevention of avian tapeworm diseases and contributing to the effective management and protection of captive bird populations.