Home Question? To Lab

Movie Gallery Home: access other parasites


Movies on the life of Hymenolepis diminuta

 Beetle feeding on eggs  This tapeworm sheds proglottids which pass out in the host's feces. Beetles acquire the infection while scavenging. In this scene, a beetle feeds on a proglottid, ingesting many of the eggs it contains.  Windows media download
~ 0.5 mb
 Quicktime download
~ 1.7 mb
 Beetles finished feeding  Even a hungry beetle will become satiated eventually and stop feeding. In this scene, beetles ignore pieces of a proglottid that remain after 15 hours. Typically, a single bout of feeding on proglottid until satiated will produce an infection with only 1-30 cysticercoids.  Windows media download
~ 0.4 mb
 Quicktime download
~ 1.3 mb
 Quiescent H. diminuta egg  This tapeworm releases fully-embryonated eggs that are immediately infective to beetles. The hexacanth embryo (= oncosphere) is enclosed in a thick set of protective membranes that help it resist environmental conditions. The hexacanth is quiescent, conserving energy to promote lengthy survival.  Windows media download
~0.3 mb
 Quicktime download
~ 1.0 mb
 Recently ruptured H. diminuta egg  When eaten by a beetle, the outer egg membranes are ruptured by the mouthparts of the beetle. This scene shows a hexacanth artificially released just seconds before. Notice that the hexacanth becomes activated almost immediately.  Windows media download
~ 0.6 mb
 Quicktime download
~ 2.0 mb
 Activated H. diminuta hexacanth  The hexacanth is so named because it possesses 6 hooks that are under muscular control. Their action within the gut of the beetle helps penetrate the gut wall and pull the hexacanth into the hemocoele of the beetle. This egg was ruptured artificially by mechanical action. This hexacanth is still enclosed within a protective membrane (the yellow bar connects the edge of the hexacanth with the edge of this membrane) that is normally digested away by enzymatic action when in the gut of the beetle.  Windows media download
~ 0.9 mb
 Quicktime download
~ 2.6 mb
 Activated hexacanth  This scene illustrates the coordinated activity of the oncospheral hooks. (Differential interference contrast microscopy.)  Windows media download
~ 0.7 mb
 Quicktime download
~ 2.1 mb
 H. diminuta cysticercoid  The infective cysticercoid comprised the scolex of the future adult tapeworm (shown here), withdrawn into and surrounded by a thick protective tissue layer. Once infective, the cysticercoid persists in a relatively quiescent state to conserve energy. However, this scene illustrates that the scolex exhibits periodic, slow contractions.  Windows media download
~ 1.4 mb
 Quicktime download
~ 4.1 mb
 H diminuta adult anterior  It is a misconception that tapeworms simply latch onto the host's gut and hang there. This adult worm, recently removed from the gut of its rat host and kept at body temperature, illustrates just how active the tapeworm can be. The dark expansion on the strobila is simply an area damaged by forceps during handling of the worm.  Windows media download
~ 0.9 mb
 Quicktime download
~ 2.9 mb
 H diminuta adult acolex and neck  This tapeworm has 4 suckers on its scolex. You can see some of their activity as they search for something to attach to.  Windows media download
~ 0.6 mb
 Quicktime download
~ 2.1 mb