Sunday, September 7, 2014

[Ichthyology • 2013] Role of Huge Geometric Circular Structures in the Reproduction of a Marine Pufferfish Torquigener albomaculosus

Figure 1: Male pufferfish, Torquigener sp. >> T. albomaculosus
The male is digging a valley with its fins and body. Photograph by K. Ito at Seisui on 23 April 2012.

We report that male pufferfishes (Torquigener sp., Tetraodontidae) constructed large geometric circular structures on the seabed that played an important role in female mate choice. Males dug valleys at various angles in a radial direction, constructing nests surrounded by radially aligned peaks and valleys. Furthermore, they created irregular patterns in the nest comprising fine sand particles. The circular structure not only influences female mate choice but also functions to gather fine sand particles in nests, which are important in female mate choice. Strangely enough, the males never reuse the nest, always constructing a new circular structure at the huge cost of construction. This is because the valleys may not contain sufficient fine sand particles for multiple reproductive cycles.

Figure 3: Changes in the circular structure constructed by male pufferfish.
(a) Early stage; (b) middle stage; (c) final stage; and (d) after spawning of the same circular structure of K1 in Figure 2. Photograph by Y. Okata on 23, 27, 29 June, and 6 July 2012, respectively.

Hiroshi Kawase, Yoji Okata and Kimiaki Ito. 2013. Role of Huge Geometric Circular Structures in the Reproduction of a Marine Pufferfish. Scientific Reports. 3[2106]