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Related Experiment Video

Updated: Jan 1, 2026

Helminth Collection and Identification from Wildlife

Helminth Collection and Identification from Wildlife

Published on: December 14, 2013

Ungulate Helminth Transmission and Two Evolutionary Puzzles.

James C Chubb¹, Daniel Benesh², Geoff A Parker¹

¹Department of Evolution, Ecology and Behaviour, University of Liverpool, Liverpool L69 7ZB, UK.

Trends in Parasitology

|December 18, 2019

Summary

This summary is machine-generated.

Grazing mammals, or ungulates, rarely get parasites directly from plants. Ungulates typically act as definitive hosts, with few exceptions, due to behaviors like fecal avoidance limiting parasite transmission.

Keywords:

faeces grazer life cycle evolution life history theory transmission strategy

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Helminth Collection and Identification from Wildlife

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Published on: December 14, 2013

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Area of Science:

Parasitology
Evolutionary Biology
Ecology

Background:

Ungulates (grazing mammals) present evolutionary puzzles regarding their roles as hosts for helminths (parasitic worms).
Key questions involve why some helminths use intermediate hosts before ungulates and why ungulates, despite being large and long-lived, are not always the definitive hosts.

Purpose of the Study:

To comprehensively survey helminth life cycles and transmission routes involving ungulates.
To investigate the evolutionary reasons behind ungulate-helminth host-parasite dynamics.
To understand the rarity of direct transmission and the infrequent role of ungulates as intermediate hosts.

Main Methods:

Systematic review and survey of existing literature on helminth life cycles and transmission involving ungulates.
Analysis of identified transmission routes and evolutionary origins of ungulate parasitism.
Examination of host-parasite relationships, focusing on definitive vs. intermediate host roles.

Main Results:

Six distinct helminth transmission routes involving ungulates were identified.
Ungulate helminth parasitism has evolved approximately 25 times.
Direct transmission of helminth eggs to ungulates is rare, likely due to fecal avoidance behavior creating a transmission barrier.
Ungulates predominantly serve as definitive hosts, with exceptions being uncommon.

Conclusions:

Ungulate fecal avoidance is a significant factor limiting direct helminth transmission.
The evolutionary trajectory of ungulate-helminth interactions favors definitive host roles, with intermediate host roles being exceptional.
Understanding these dynamics is crucial for wildlife health and parasite management in grazing mammal populations.