Flatworms

Coral Sea, Duration 88 seconds

Indo-Pacific, Shot at night, Duration 15 seconds

Coral Sea, Shot at night, Duration 37 seconds

Coral Sea, Duration 23 seconds

South Pacific Ocean, Duration 15 seconds

Hampen Sø, Midtjylland, Danmark

Roskilde

Ørn Sø, Silkeborg, Danmark

Mattrup Å ved Stidsmølle, Jylland, Danmark

Ørn Sø, Silkeborg, Danmark

Dollerup Kilde ved Hald Sø, Jylland, Danmark

Life cycle of Spirometra tapeworms causing sparganosis in humansAdult tapeworms in the genus Spirometra live in the intestines of dogs and cats (7). Eggs are shed in feces (1) and embryonate in the environment (2). Eggs hatch in water and release coracidia (3), which are ingested by copepods. The coracidia develop into procercoid larvae in the copepod intermediate host (4). Second intermediate hosts, including fish, reptiles and amphibians, ingest infected copepods and acquire procercoid larvae. The procercoid larvae develop into plerocercoid larvae in the second intermediate host (5). The cycle is completed when a predator (dog or cat) eats an infected second intermediate host (6). Humans cannot serve as definitive hosts for Spirometra spp., but serve as paratenic hosts ("transport hosts") or second intermediate hosts (8) and develop sparganosis. Humans acquire sparganosis by either drinking water contaminated with infected copepods or consuming the flesh of an under-cooked second intermediate or paratenic host. Larvae of these tapeworms (spargana) can live up to 20 years in the human host.From Centers for Disease Control Parasites and Health website.

Polyclad worm.

Figure 1.Alaria chengguanensis sp. n., male holotype. A Pedipalp, prolateral view B Pedipalp, ventral view C Embolic division, dorsal view D Pedipalp, retrolateral view. Co conductor; MA median apophysis; PC paracymbium; T tegulum. Scale bars: D as A.

Figure 1.Geographic distribution of Dugesia superioris (indicated by an asterisk) and Dugesia sp. NMNH 55294 (indicated by black diamond) in the Lake Ohrid region.

Figure 1.Cycloporus papillosus. A–D dorsal views of living animals E sagittal reconstruction of a whole specimen F sagittal reconstruction of the copulatory apparatus. Anterior to the right in E, F.

Figure 1.Geographic distribution of Dugesia species recorded from Madagascar and adjacent islands. Type locality of Dugesia bifida in the High Tsiribihina hydrographic basin indicated by an asterisk.

Wilsons Promontory, Victoria, Australia

This is the only figure from M. Schultze's original description of Prorhynchus stagnalis. He thought that it was an aberrant nemertean; hence the anus (which, I assure you, does not exist in reality).

Mabul, Sabah, Malaysia