A Miniature Intermittent-Flow Respirometry System with a 3D-Printed, Palm-Sized Zebrafish Treadmill for Measuring Rest and Activity Metabolic Rates

Abstract

Zebrafish are a preferred vertebrate model for evaluating metabolism during development, and for toxicity studies. However, commercially available intermittent-flow respirometry systems (IFRS) do not provide a suitable zebrafish-scaled swimming tunnel with a low water volume and proper flow velocities. We developed a miniature IFRS (mIFRS) with a 3D-printed, palm-sized zebrafish treadmill for measuring the swimming ability and metabolic rate of a single one- or three-month-old zebrafish with and without toxicity treatment. The 3D-printed zebrafish treadmill consists of discrete components assembled together which enables the provision of a temporary closed circulating water flow. The results showed that three-month-old zebrafish of normal physiological status had higher energetic efficiency and could swim at a higher critical swimming speed (Ucrit) of 16.79 cm/s with a lower cost of transport (COTopt) of 0.11 μmol g−1m−1. However, for a single three-month-old zebrafish treated with an antibacterial agent, Ucrit decreased to 45% of normal zebrafish and the COTopt increased to 0.24 μmol g−1m−1, due to the impairment of mitochondria. Our mIFRS provides a low-cost, portable, and readily adaptable tool for studying the swimming performance and energetic metabolism of zebrafish.

Assessing metabolic rates in zebrafish using a 3D-printed intermittent-flow respirometer and swim tunnel system

“…This value is in good agreement with the value of ∼149 µmol O 2 ·min −1 ·kg −1 measured by Lucas et al (2014) on similar-sized zebrafish, using a protocol with pre- and post-blank measurements, but at a slightly higher temperature of 28°C. The study by Huang et al (2020) , using a system similar to ours, reported a much higher SMR value of ∼450 µmol O 2 ·min −1 ·kg −1 in young adult zebrafish (∼130 mg). However, they did not correct for background respiration, which may have contributed to overestimation of the SMR.…”

“…However, divergent values of adult zebrafish metabolic rates are found in the literature. Studies have reported highly different SMR values ( Lucas et al, 2014 ; Huang et al, 2020 ) and generally low factorial aerobic scopes ( Lucas et al, 2014 ; Huang et al, 2020 ; Ripley et al, 2022 ; Morgan et al, 2022 ), suggesting that MMR might have been underestimated. Here, we describe how to accurately determine SMR and MMR of zebrafish under ramping exercise.…”

Modeling Human Muscular Dystrophies in Zebrafish: Mutant Lines, Transgenic Fluorescent Biosensors, and Phenotyping Assays

“…Recently, a swimming tunnel instrument was developed to measure different parameters linked to the motor behavior of both zebrafish larvae and adults. It consists of a glass tube, filled with fish water, connected to a specific instrument that measures parameters, such as distance moved, muscle force, oxygen consumption rate, and metabolic changes, which will be recorded on a computer equipped with specific software [124][125][126][127][128].…”

Automated flow control of a multi-lane swimming chamber for small fishes indicates species-specific sensitivity to experimental protocols

“…Applications, such as computer-aided design (CAD) and computational fluid dynamics (CFD) software, can help to develop and test swimming chambers and their flow dynamics virtually ( Vezza et al , 2020 ). Similarly, computer-controlled cutting or 3D printing machines assist with creating pieces for swimming flumes, often on very small scales ( Huang et al , 2020 ). At the same time, microcontrollers can control flow settings in swimming flumes more accurately, as they reduce delays in flow changes associated with manually operated valves ( Widrick et al , 2018 ).…”