Cestodes have a scolex with two longitudinal bothria. There are hooks present and they also have genital pores that are lateral or medial, which depends on the species. They also have numerous testes. The life cycle of this parasite involves a crustacean as the first intermediate host and a fish as the second intermediate host. The size of the species varies widely and the largest known measure more than 40 meters long. Each segment has four to fourteen complete sets of genitalia.
The scolex of the Diphyllobothrium is finger-shaped and has dorsal and ventral proglottids that are usually wider than long. They also have numerous testes and vitelline follicles that are present in each proglottid.
Once ingested by a copepod, the coracidium loses …show more content…
The scolex has a four simple suckers that varies when it comes to the presence of hooks and a rostellum. Genital pores are lateral and the ovary is posterior and there are numerous testes that fill the region anterior to the ovary. Follicular vitelline cells are located on the margins of the proglottids.
Involves a cyclopoid crustacean as the intermediate host as the worm develops into a procercoid. It has a well developed scolex and a cercomer at the posterior end. The procercoid can be directly infective to some hosts. In other hosts, the procercoid burrows in viscera. Once it emerges from the viscera, it moves to the lumen of the gut where it matures into a proteocephalus. The proteocephalus burrows into the intestinal wall and loses its cercomer as it penetrates.
The scolex of this group is unique. They are elongated with two or four shallow bothridia. It cna be covered with minute microtriches. Four tentacles emerge from the apex of the scolex. These tentacles have a muscular bulb at its base and a retractor muscle originates at the base or in front of the bulb. When the retractor muscle contracts, it cause the tentacles to invaginate and results in the parasite detaching from the host tissue. When the bulb contracts, it causes the tentacles to protrude and dig into the host's intestinal wall. It also contains a single ovary that is bilobed and anterior in the proglottid. The uterus is a simple sac and there can be anywhere from a few to many
The scolex of the Diphyllobothrium is finger-shaped and has dorsal and ventral proglottids that are usually wider than long. They also have numerous testes and vitelline follicles that are present in each proglottid.
Once ingested by a copepod, the coracidium loses …show more content…
The scolex has a four simple suckers that varies when it comes to the presence of hooks and a rostellum. Genital pores are lateral and the ovary is posterior and there are numerous testes that fill the region anterior to the ovary. Follicular vitelline cells are located on the margins of the proglottids.
Involves a cyclopoid crustacean as the intermediate host as the worm develops into a procercoid. It has a well developed scolex and a cercomer at the posterior end. The procercoid can be directly infective to some hosts. In other hosts, the procercoid burrows in viscera. Once it emerges from the viscera, it moves to the lumen of the gut where it matures into a proteocephalus. The proteocephalus burrows into the intestinal wall and loses its cercomer as it penetrates.
The scolex of this group is unique. They are elongated with two or four shallow bothridia. It cna be covered with minute microtriches. Four tentacles emerge from the apex of the scolex. These tentacles have a muscular bulb at its base and a retractor muscle originates at the base or in front of the bulb. When the retractor muscle contracts, it cause the tentacles to invaginate and results in the parasite detaching from the host tissue. When the bulb contracts, it causes the tentacles to protrude and dig into the host's intestinal wall. It also contains a single ovary that is bilobed and anterior in the proglottid. The uterus is a simple sac and there can be anywhere from a few to many