This work investigates the effects of androgenic gland (AG) ablation on the structure of the reproductive
system, development of secondary sexual characters and somatic growth in Cherax quadricarinatus males.
The AG ablation, which was performed at an early developmental stage (initial weight: 1.85 ± 0.03 g), had
no effect on the somatic growth parameters (specific growth rate and growth increment), but it prevented
the re-formation of male gonopores and appendices masculinae. However, the red patch differentiation
and chelae size were similar to those in control males. All the ablated animals developed a male
reproductive system. Testis structure was macroscopically and histologically normal. The distal portion
of the vas deferens (DVD) was enlarged in some animals, with histological alterations of the epithelium
and the structure of the spermatophore. Results suggest that the higher growth in males than in females
may be due to an indirect effect of the AG on energy investment in reproduction rather than to a direct
effect of an androgen. This is the first report of a potential action of the AG on the secretory activity of the
distal VD and the structural organization of the spermatophore. Although the AG may play a role in the
development of male copulatory organs, its association with the red patch development deserves further
research. The results obtained in the present study support and complement those from intersexes of the