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4 Cards in this Set
- Front
- Back
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name the general diagnostic characteristic of the order Strongylida
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Copulatory bursa with 2 spicules
obvious ovijector apparatus simple, non-operculate, thin-shelled, 80x40um eggs infective stage always [L3] infection by ingestion or skin penetration |
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describe the typical life cycle of a nematode belonging to the order Strongylida (direct, oral infection)
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egg (morula) passed in faeces, L1 develops in egg and hatches, L1 feeds on bacteria, grows and enters lethargus, moult to L2, incomplete moult to [L3], infective stage ingested by host, L3 exsheathes immediately anterior to area where adult lives, enters mucosal gland crypts, molts to L4 and may emerge on to the surface of mucosa, L4 feeds, molts and molts to immature adult which feeds and grows to sexual maturity
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development outside the host requires...
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oxygen, stable temperature (10-30 degrees, optimum for development 25 degrees), moisture (to avoid desiccation and allow movement)
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What are the chemical stimuli for exsheathment?
what is the optimal temperature range? |
pH and the equilibrium between carbon dioxide, bicarbonate and carbonic acid
37-39 degrees |
