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The reproductive system a female Lucanus cervus

Below is a wonderful view of the reproductive organs of a recently deceased female Lucanus cervus. This female was captured at the end of the season, 30 July 2012, in Colchester, Essex, UK, and sent to Japan for further studies, unfortunately it did not survive the journey. Even so, Dr. Masahiko Tanahashi was able to dissect her and share his finding with the website.

Reproductive system of a female stag beetle

Microscopic view of the reproductive system of an old female Lucanus cervus
Photo courtesy of Dr. Masahiko Tanahashi

Lucanus cervus females have a pair of ovaries with 12 ovarioles each [1]; the ovarioles are spread out, not bunched up like in most diagrams [2]. However, one can't see all of them because they were rather damaged. This is not at all surprising, she had reached the end of her reproductive life by the time she was shipped.
However, judging from the presence of the “yellow bodies” in the proximal part of every ovariole, she might have deposited at least 24 eggs. A very productive life for a stag beetle!

More good news: the Pichia yeasts in the mycangium of the dead female survived the journey, therefore Dr. Masahiko Tanahashi was able to culture and isolate them successfully, see below. This was the main reason why this female went to Japan because it seems that each stag beetle species has its own specific Pichia yeasts and there are no Lucanus cervus in Japan [3].

Pichia yeasts

Symbiotic Pichia yeasts isolated from the mycangium of Lucanus cervus (dead specimen).
Photo Masahiko Tanahashi, 2012.

This female would have passed on these micro-organisms to the next generation when she laid her eggs. If you want to know more about this very clever stag beetle trick, click here.

[1] - Scholtz, C.H. and Grebennikov, V. V., 2005. Scarabaeioidea Latreille, 1802, pp. 367-425. Handbook of Zoology, Vol. IV, Arthropoda, Part II, Insecta (edited by N.P. Kristensen and R.G. Beutel), Coleoptera, Vol. 1: Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) (edited by R.G. Beutel and R.A.B. Leschen). Walter De Gruyter, Berlin.
[2] - Female Reproductive System - An interesting tutorial by Dr. John R. Meyer, NC State University. However, it does show the ovarioles bunched up.
[3] - Tanahashi, M., Kubota, K., Matsushita, N.& Togashi, K. (2010) - Discovery of mycangia and the associated xylose-fermenting yeasts in stag beetles (Coleoptera: Lucanidae). Naturwissenschaften 97: 311-317.


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Created: Mon Sep 10 2012
Last modified: Fri Dec 28 10:25:02 GMT 2012

| Main | Stag beetle Lucanus cervus life cycle | Protruded organs |