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The journey of sperm from its origin to the point of ejaculation begins within the seminiferous tubules of the testis. Here, Sertoli cells produce fluid that propels non-motile sperm through a series of conduits, starting with the straight tubules leading to the rete testis. This interconnected network of tubules acts as the initial pathway for sperm, guiding them into the efferent ductules and then into the epididymis for maturation.
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Spermatogenesis

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Related Experiment Video

Updated: Jun 12, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila

Assessing Differences in Sperm Competitive Ability in Drosophila

Published on: August 22, 2013

Sperm competition and ejaculate economics.

Geoff A Parker¹, Tommaso Pizzari

¹Division of Population and Evolutionary Biology, School of Biological Sciences, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK. gap@liverpool.ac.uk

Biological Reviews of the Cambridge Philosophical Society

|June 22, 2010

Summary

Sperm competition drives male strategies for sperm production and allocation. This review synthesizes ejaculate economics theory, reconciling models and highlighting empirical support for diverse ejaculate traits.

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Last Updated: Jun 12, 2026

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Area of Science:

Evolutionary Biology
Sexual Selection
Behavioral Ecology

Background:

Sperm competition is a key post-copulatory sexual selection force.
Males evolve strategies to optimize sperm production and allocation under competition.
Theoretical models of ejaculate economics present complex and varied predictions.

Purpose of the Study:

To synthesize the theoretical basis of ejaculate economics under sperm competition.
To categorize model assumptions and predictions for empiricists.
To reconcile apparent contradictions between older and newer theoretical models.

Main Methods:

Review and synthesis of theoretical models of ejaculate economics.
Categorization of model assumptions and predictions.
Discussion of empirical support, including quantitative data from yellow dung flies.

Main Results:

Reconciliation of apparent contradictions between theoretical models.
Identification of considerable consensus in model predictions.
Demonstration of ejaculate economic theory as a heuristic for explaining ejaculate trait diversity.

Conclusions:

Ejaculate economic theory effectively explains diversity in ejaculate traits across species, males, and within individuals.
Future research should focus on sperm competition mechanisms, trade-offs, female sperm selection, non-sperm ejaculate effects, and integrating pre- and post-copulatory sexual selection.