Strobila segmented. Two types of scolex, primary club-shaped with four tentacles, bothria absent. Primary strobila has segmented regions at intervals behind the primary scolex, each of which separates off to become a secondary strobila; anterior segment of secondary strobila modified as secondary scolex, which is flattened anteriorly, with four shallow indentations around raised central dome. Proglottids craspedote with four flat projecting appendages, longer than wide. Reproductive organs single in segment; testes multiple; external seminal vesicle large, attached to proximal part of cirrus-sac; cirrus armed with minute spines; ¬ovary medullary, compact; genital pore ventral; vitellarium follicular, medullary; uterus with coiled uterine duct and dilated uterine sac; uterine pore ventral, persistent or transient. Eggs with operculum, embryonated in uterus; free ciliated coracidium present.
Only two nominal species in genus Haplobothrium (H. globuliforme, H. bistrobilae).
The affinities and systematic position of Haplobothrium is controversial. Cooper (1914) described H. globuliforme on the basis of a secondary scolex as a member of the family Diphyllobothriidea. Later Cooper (1917) discovered the tentacle-bearing primary scolex and erected the subfamily Haplobothriinae. The primary scolex resembles those of members of Trypanorhyncha, but morphology of proglottides is similar to that of the members of Diphyllobothriidea. Most of recent phylogenetic analyses support close relationships of the Haplobothriidea with the Diphyllobothriidea.
Parasites of bowfin, Amia calva.
Intestine.
North America(USA).
Three hosts in life-cycle. Eggs develop and hatch in water liberating a coracidium (hexacanth enclosed in a ciliated envelope), which is eaten by copepod, hexacanth penetrates into its haemocoel where it develops into procercoid. Second hosts are freshwater teleosts (Lebistes reticulatus, Lepomis gibbosus), in which plerocercoid encysts in the liver.
Selected References:
Cooper, A. R. 1918. North American pseudophyllidean cestodes from fishes. Illinois Biological Monographs Vol. 4, No. 4, 243 pp. PDF
Meinkoth, N. A. 1947. Notes on the life cycle and taxonomic position of Haplobothrium globuliforme Cooper, a tapeworm of Amia calva L. Transactions of the American Microscopical Society 65: 256-261. PDF
MacKinnon, B. M., L. Jarecka, and M. D. B. Burt. 1985. Ultrastructure of the tegument and penetration of developing procercoids of Haplobothrium globuliforme Cooper, 1914 (Cestoda: Haplobothrioidea). Canadian Journal of Zoology 63: 1470-1477.
Jones, A. 1994. Order Haplobothriidea Joyeux & Baer, 1961. In Keys to the cestode parasites of vertebrates, L. F. Khalil, A. Jones, and R. A. Bray (eds.). CAB International, Wallingford, U.K., p. 249-251. PDF
Taxon Coordinator:
Dr. Roman Kuchta
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: krtek@paru.cas.cz
