Final answer:
The given statement about Onchocerca cervicalis is incorrect; this parasite produces microfilariae that live in connective tissue, not eggs on the horse's external surfaces. Parasites' complex life cycles often involve multiple stages and hosts, with significant health impacts on their primary host.
Step-by-step explanation:
The statement that Onchocerca cervicalis adults deposit eggs on the horse's leg hair, lips, and intermandibular space is not accurate. Instead, Onchocerca cervicalis, which is a filarial nematode causing onchocerciasis in horses, produces microfilariae rather than direct eggs. These microfilariae are the larval stage of the parasite and are found in the connective tissue rather than externally on the hair or skin.
The life cycle of many helminth parasites, like Onchocerca cervicalis, involves complex host interactions and different developmental stages. For instance, adult worms in diseases such as schistosomiasis and strongyloidiasis release eggs or larvae that can cause significant health issues in the infected host.
These life cycles often involve environmental stages and sometimes intermediate hosts, such as snails for schistosomiasis or deerflies for Onchocerca species, that help in the transmission of the parasite. The transmission and development process of parasites like tapeworms and hookworms follow a cycle that allows them to infect their hosts, mature, reproduce, and continue their life cycle.