Adult free full length hosted

The tsetse are obligate parasites that live by feeding on the blood of vertebrate animals. Tsetse have been extensively studied because of their role in transmitting disease. They have a prominent economic impact in sub-Saharan Africa as the biological vectors of trypanosomes , which cause human sleeping sickness and animal trypanosomiasis. Tsetse are multivoltine and long-lived, typically producing about four broods per year, and up to 31 broods over their lifespans.

Schistosomiasis Bilharziasis is caused by some species of blood trematodes flukes in the genus Schistosoma. The three main species infecting humans are S chistosoma haematobium , S. Three other species, more localized geographically, are S. There have also been a few reports of hybrid schistosomes of cattle origin S. Unlike other trematodes, which are hermaphroditic, Schistosoma spp. In addition, other species of schistosomes, which parasitize birds and mammals, can cause cercarial dermatitis in humans but this is clinically distinct from schistosomiasis.

Some species are planktonic drifting in sea waters , some are benthic living on the ocean floor , a number of species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses phytotelmata of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes , or stream beds. Copepods are sometimes used as biodiversity indicators.

All parasites have a life cycle that involves a period of time spent in a host organism and that can be divided into phases of growth, reproduction, and transmission. Life cycles of parasites can be further divided into two categories: direct monoxenous and indirect heteroxenous. Parasites with direct life cycles spend most of their adult lives in one host, known as the parasitic stage, with their progeny transmitted from one host to another, known as the free-living stage. Direct parasites often lack an intermediate stage and must leave their host.