Last Updated: June 10, 2026

MORPHOLOGY: Scolex with 4 bothridia borne on stalks; bothridia of most with marginal and/or facial loculi, arrangement of loculi variable; myzorhynchus present or absent. Vas deferens joining cirrus at anterior margin, rather than proximal end, of cirrus sac; post-poral testes usually lacking. Vagina opening anterior to cirrus sac; ovary bi- or tetra-lobed; vitellarium follicular; follicles arranged in 2 lateral fields, occasionally encroaching on median line of proglottid. Worms generally small, most species range in length from 3 mm to 3 cm.

DIVERSITY: Currently, 13 valid genera are assigned to the order.

PHYLOGENETIC RELATIONSHIPS: The order was recently established to house a subset of genera formerly assigned to the Order Tetraphyllidea, following a molecular phylogenetic analysis which showed the tetraphyllideans bearing stalked bothridia to comprise a distinct clade from those mostly lacking stalks. Interrelationships among genera remain to be formally determined.

DEFINITIVE HOSTS: The rhinebothrideans parasitize elasmobranchs (sharks and rays) as adults; most species are known from batoids (i.e., stingrays, eaglerays, skates, guitarfish, etc.).

SITE IN DEFINITIVE HOST: Spiral intestine.

GEOGRAPHIC DISTRIBUTION: Cosmopolitan, with greatest diversity in tropical and subtropical regions, but some genera (e.g., Echeneibothrium and Pseudanthobothrium) more common in cooler waters. Mostly marine; some species infecting freshwater stingrays of South America and Borneo.

LIFE-CYCLES: Likely a three host life-cycle but no complete life-cycle is known. Eggs develop in utero or in water, and hatch liberating a hexacanth that is eaten by a crustacean, likely a copepod; the hexacanth penetrates into haemocoel where it develops into a procercoid. Consumption of the procercoid in the copepod by the second intermediate host, likely a bivalve mollusk or teleost, leads to development of the plerocercoid which usually bears an apical sucker and 4 retractable acetabula that may be facially loculated, or exceptionally (Rhodobothrium) consists of a bladder containing a distal pedunculated swelling and a scolex.

Selected References:

Euzet, L. 1994. Order Tetraphyllidea. Pp. 149–194. In Khalil, L. F., Jones, A., bray, R. A. (Eds.) Keys to the cestode parasites of vertebrates. CAB International, Wallingford, U.K. PDF

Healy, C. J. 2006. A revision of selected Tetraphyllidea (Cestoda): Caulobothrium, Rhabdotobothrium, Rhinebothrium, Scalithrium, and Spongiobothrium. Ph.D. Dissertation. University of Connecticut.

Healy, C. J., J. N. Caira, K. Jensen, B. L. Webster, and D. T. J. Littlewood. 2009. Proposal for a new tapeworm order, Rhinebothriidea. International Journal for Parasitology 39: 497–511. PDF

Ruhnke, T. R. 2010. A monograph on the Phyllobothriidae (Platyhelminthes: Cestoda). Bulletin of the Nebraska State Museum. 25: 205 pp. PDF

Taxon Coordinators:

Dr. Florian Reyda

State University of New York
College at Oneonta
Department of Biology
Oneonta NY, USA

Dr. Claire Healy

Royal Ontario Museum
Department of Natural History
Toronto ON, CANADA