Scanning electron micrograph (SEM) of scolex of Diplocotyle olrikii; SEM of apical view of scolex of Diplocotyle olrikii; SEM of scolex of Cyathocephalus truncatus; top: progenetic Bothrimonas sp. emerging from a crustacean; bottom: egg of Bothrimonas sp. and example host of spathebothriideans (Liparis sp.). (Photos courtesy of R. Kuchta & T. Scholz; Liparis sp., http://dnr.metrokc.gov)
Scolex with single funnel-shaped organ or forwardly directed sucker-like attachment organ with lumina completely separated internally by a median septum or completely fused, with only a rudimentary septum at the base, or undifferentiated. Polyzoic, with linear multiplication of reproductive organs, but without external evidence of segmentation. Testes in continuous, irregular lateral bands throughout most of length of body. Male and female pores separate, median, located close to one another on same surface of body, irregularly alternating dorsally and ventrally along length of body, or just ventral. Ovary rosette-shape or bilobed. Uterus tubular and convoluted. Eggs with large operculum, may be embryonated in the uterus, with or without filaments.
Six valid species in 5 genera in 2 families (1 monotypic).
Spathebothriideans are a monophyletic group of undoubtedly basal cestodes. Their basal position has been supported by both morphological and molecular analyses but relationships to other basal orders are still unclear.
Freshwater, euryhaline, and marine chondrosteans and teleosts.
Intestine.
Northern Hemisphere, mostly arctic.
Two host life-cycle. Metacestodes (plerocercoids) in the body cavity of amphipod crustaceans. Progenesis is widespread in the group, several forms being able to mature and produce eggs as plerocercoids in crustaceans.
Selected References:
Nybelin, O. 1922. Anatomisch-systematische Studien über Pseudophyllideen. Göteborgs kungl. Vetenskaps-och Vitterhets-Samhälles Handlingar XXVI, Med bihang 41: 1-128. PDF
Gibson, D. I. 1994. Order Spathebothriidea Wardle & McLeod, 1952. pp. 15-19. In Khalil, L. F., Jones, A., Bray R. A (Eds.) Keys to the cestode parasites of vertebrates. CAB International, Wallingford, U.K.
Protasova, E. N., and V. A. Roitman. 1995. Cyathocephalata – tapeworm helminths of marine and freshwater fishes (Cestoda: Pseudophyllidea: Cyathocephalata). Essentials of Cestodology, Vol. 12, Nauka, Moscow, 135 pp. (In Russian).
Taxon Coordinator:
Dr. Tomás Scholz
Institute of Parasitology
Academy of Sciences of the Czech Republic
Branisovská 31
370 05 Ceské Budejovice
Czech Republic
PHONE: ++420-38- 53-10-351
E-MAIL: tscholz@paru.cas.cz
