The Nest of Torquigener Albomaculosus: Fluid-Dynamic Aspects and Potential for Bio-Inspired Engineering

Abstract

Torquigener albomaculosus, also known as the white-spotted pufferfish, is known for creating circular nests in the underwater sand as part of the mating ritual. The nests are built by the males to attract females through the nest's impressive design and related ability to gather fine sand particles. As the fluid-dynamic processes associated with these unique nests are still almost completely unknown, in the present study, an analysis has been conducted to investigate how the geometric parameters related to the nest design influence the fluid velocity in its center. For this reason, a geometric model of the nest consisting of 24 channels, where each unit channel can be described by three strips of broken lines, has been introduced, and a multivariate analysis has been implemented to determine the relative weight of each considered parameter. In particular, the "optimal" combination of parameters has been obtained by means of an orthogonal design approach. We show that these bio-nest structures also display a potential for significant application in marine litter collection, or for use as a buffer against the waves in offshore areas.