Last Updated: June 10, 2026
MORPHOLOGY: Body typically small, can reach up to 100 mm. Scolex with 4 unarmed suckers. Rostellar apparatus mostly musculo-glandular, with invaginable rostellum. Rostellar hooks in 2 rows, when rostellum invaginated hooks with blades anteriorly directed. Strobila consisting of 3-4 to several dozen craspedote proglottids. Genital pores unilateral or alternating, situated on lateral proglottid margin. Proglottids hermaphroditic, with a single set of genital organs. Testes ranging between 3 and several dozen in number. Seminal vesicles lacking, functionally replaced by coiled vas deferens. Ovary usually two-winged or fan-shaped, lobate, median. Vitellarium compact or lobate, posterior to ovary. Uterus variable in structure: sac-like, often strongly branched.
DIVERSITY: Twelve genera, about 100 species.
PHYLOGENETIC RELATIONSHIPS: Gryporhynchids were revealed to be a sister group of the amabiliids from grebes (schistotaeniids) and are basal to the acoleids, progynotaeniids, dioecocestids and hymenolepidids.
DEFINITIVE HOSTS: Fish-eating birds: herons, ibises, spoonbills, cormorants, pelicans, also in birds of prey and rails; one species described from Australian freshwater turtles.
SITE IN DEFINITIVE HOST: Small intestine.
GEOGRAPHIC DISTRIBUTION: Cosmopolitan.
LIFE-CYCLES: Gryporhynchids have a 3-host life-cycle including crustaceans as first intermediate hosts, fish as second intermediate hosts, and fish-eating birds as definitive hosts.
Selected References:
Matevosyan, E. M. 1963. Dilepidoidea – tapeworms of domestic and wild animals. in Skrjabin, K.I. (Ed) Osnovy Tsestodologii, Volume 3, Moscow, Izdatel’stvo Akademii Nauk SSSR, 687 pp. [In Russian.] PDF
Bona, F. 1975. Etude critique et taxonomique des Dilepididae. Fuhrm., 1907 (Cestoda) parasites de Ciconiiformes. Considerations sur la specificite et la speciation. Monitore Zoologico Italiano N.S. Monografia 1, 750 pp. PDF
Bona, F. 1994. Family Dilepididae Railliet & Henry, 1909. pp. 443-554. In Khalil, L .F., Jones, A., Bray, R. A. (Eds.) Keys to the cestode parasites of vertebrates. CAB International, Wallingford, U.K. PDF
Scholz, T., R. A. Bray, R. Kuchta, and R. Repová. 2004. Larvae of gryporhynchid cestodes (Cyclophyllidea) from fish: a review. Folia Parasitologica 51(2-3): 131-52. PDF
Taxon Coordinator:
Dr. Jean Mariaux
Invertebrates Department
Natural History Museum Geneva
Geneva, SWITZERLAND
