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Movies on the life of Echinostoma caproni

 E caproni embryonated egg  These 11-day-old eggs contain a fully-developed miracidium. Body movements are evident as the miracidia prepare to hatch. (Differential interference contrast microscopy.)  Windows media download
~ 0.3 mb
 Quicktime download
~ 1.3 mb
 E caproni miracidia ciliary action  This recently-hatched miracidium has come up against an obstacle (a yellowish rod on the right side) and so is immobilized. This presents an opportunity to examine the action of the cilia that coat the surface of the miracidium and enable it to swim in search of a molluscan host. The red color of the internal structures results from vital dye staining with Neutral Red. (Bright field microscopy.)  Windows media download
~ 0.3 mb
 Quicktime download
~ 0.8 mb
 E caproni miracidia ciliary action  The cilia on the surface of the miracidium are shown clearly. (Differential interference contrast microscopy.)  Windows media download
~0.3 mb
 Quicktime download
~ 1.0 mb
 E caproni miracidium swimming  Miracidia exhibit straight-line and circular swimming behaviors. This miracidium is swimming in circles. (Differential interference contrast microscopy.)  Windows media download
~ 0.3 mb
 Quicktime download
~ 1.0 mb
 E caproni miracidia swimming action  This low-magnification scene illustrates an egg culture undergoing a period of mass hatching of miracidia. Numerous miracidia are shown swimming across the field in a more-or-less straight line fashion. Eggs from the culture are visible in the background. (Dark field microscopy.)  Windows media download
~ 0.4 mb
 Quicktime download
~ 1.1 mb
 E caproni miracidia near snail host  Recently-hatched miracidia seek a molluscan host (in this case the snail Biomphalaria glabrata) to penetrate and infect. However, the miracidia rarely home in directly. This scene illustrates several miracidia circling in the vicinity of the snail's head-foot.  Windows media download
~ 0.4 mb
 Quicktime download
~ 1.1 mb
 E caproni sporocysts near snail heart  During the infection process, the miracidium sheds its ciliated covering and becomes a tubular sporocyst as it penetrates the snail. In this species the sporocyst migrates to the heart where it continues to develop. This scene illustrates several sporocysts inside the beating heart of the snail. (Dark field microscopy.)  Windows media download
~ 0.4 mb
 Quicktime download
~ 1.1 mb
 E caproni intramolluscan stages  Sporocysts produce rediae that migrate to the ovo-testis of the snail and eventually release cercariae. Dissection of the ovo-testis reveals both stages. The rediae are mobile, as are the cercariae.  Windows media download
~ 0.3 mb
 Quicktime download
~ 1.0 mb
 E caproni rediae  This scene illustrates the activity of several rediae. Small ambulatory buds that help the redia crawl through snail tissues are visible on several of the rediae.  Windows media download
~ 0.5 mb
 Quicktime download
~ 1.4 mb
 E caproni redia giving birth  Cercariae develop continuously and asexually from germ balls within the redia. Development is asynchronous. When fully developed, cercariae exit the redia through a birth pore near the anterior end. This scene illustrates a cercaria struggling to move through the birth pore; only its anterior end is protruding.  Windows media download
~ 0.5 mb
 Quicktime download
~ 1.4 mb
 E caproni cercariae swimming and crawling  Dissection of infected snails reveals cercariae in various stages of development. One cercaria in this scene is fully developed and trapped in a strand of mucus. The rapid side-to-side movement of the tail is thy typical swimming action for this species. The other cercaria has only a partially developed tail but illustrates the common ability of flatworms to crawl by alternately gripping with oral and then ventral suckers, and extending their flexible body.  Windows media download
~ 0.6 mb
 Quicktime download
~ 1.3 mb
 E caproni metacercariae in situ  This species uses the same species of snail as first and second intermediate host. When cercariae infect a snail they shed their tail and the body crawls to its final location, in this case a spot near the heart, and encysts as a metacercaria. This scene illustrates several dozen metacercariae just to the right of the beating heart.  Windows media download
~ 0.3 mb
 Quicktime download
~ 1.0 mb
 E caproni flame cell in metacercaria  The metacercaria is a relatively quiescent stage adapted for lengthy survival to await ingestion of the host snail by a suitable final host. There is little activity visible except for the beating of flame cells which are an important component of the excretory system of flukes.  Windows media download
~ 0.3 mb
 Quicktime download
~ 0.9 mb
 E caproni adults in intact gut  Adults of this fluke exhibit a strong tendency to cluster together within the intestine of their rodent host. This segment of intestine, only a few cm long, contains 19 adult flukes. The motion of the intestine is due to the writhing of the adults flukes within it.  Windows media download
~ 0.7 mb
 Quicktime download
~ 3.2 mb
 E caproni adults in situ  This recently-opened segment of intestine illustrates the clustering of adults and their activity at body temperatures. The adults grip the intestine with their oral and/or ventral suckers.  Windows media download
~ 0.3 mb
 Quicktime download
~ 1.0 mb
 E caproni adults in situ  Living worms are fairly transparent. This scene illustrates two adjacent adults, oral ends toward the right. The oral suckers, each containing a bubble, are free because the worms are gripping the intestinal wall with their ventral suckers. the reddish mass at the anterior of each worm is its uterus, full of eggs.  Windows media download
~ 1.1 mb
 Quicktime download
~ 2.9 mb
 E caproni adult anterior  This adult worm, recently removed from its host and kept at body temperature, illustrates the speed, flexibility and muscular control that platyhelminthes are capable of.  Windows media download
~ 0.7 mb
 Quicktime download
~ 2.2 mb
 E caproni adults attach tightly to gut  The ventral sucker (acetabulum) is a powerful holdfast organ, and a vital adaptation for parasitism of the intestinal lumen where strong physical forces would otherwise dislodge and expel the parasite. In this scene a worm attached to a piece of intestine is lifted, and the attachment is powerful enough to lift the large piece of intestine along with it.  Windows media download
~ 0.9 mb
 Quicktime download
~ 1.6 mb