The zebrafish (Danio rerio) has become a popular model organism in biomedical research. Multiple advantages of using this species in biomedicine include high physiological and genetic homology to mammals, external fertilization, rapid development, transparency of embryos and larvae, ease of genetic and other experimental manipulations, as well as cost- and space-effectiveness (1). Zebrafish larvae require live food to stimulate their hunt reflex. Algae-feeding rotifers are the ideal candidate food for zebrafish and other larval finfish cultures. An HJF investigator has devised a system for automating some of the processes required for maintaining rotifer cultures.

Applications and Advantages

• The device maintains the ideal concentration of algae in a rotifer culture by measuring with a turbidity probe
• Dispenses algae into rotifer culture automatically
• Has an alert to warn if the turbidity probe becomes clogged with algae
• Design also accommodates pH control pump

Innovation Description

Rotifers are a vital part of marine larval finfish culture and have been increasingly used in laboratory zebrafish culture (2, 3). Presently, maintenance of a stable rotifer culture requires significant amounts of labor by trained personnel. Rotifers in each rotifer culture must be counted daily and algae dosing must be adjusted accordingly. When labor costs are included, the cost of maintaining a single rotifer culture can approach $10,000 per year. For many labs, this makes rotifer management costs prohibitive. An HJF investigator has designed a device that automatically doses algae, eliminating the need for tedious daily rotifer counting. This reduces the total labor required to maintain a culture from 1-2 hours per day to 1-2 minutes per day. The only daily manual task that still needs to be completed is checking the algae level in the reservoir. The turbidity probe is coated to reduce fouling. The device has three main functions: measuring algae concentrations in the rotifer culture, dosing algae from the reservoir into the culture, and indicating when the turbidity probe becomes fouled. The device has a manual control button for operating the pump manually should algae supplies become depleted or if there are any issues with the pump control circuit. Optionally, the device can also accommodate a pH control pump.

Inventors

• Benjamin J. Garcia, HJF

Innovation Status

The system has been successfully used for rotifer maintenance in the Dept. of Psychiatry at USUHS. Please see the following publications: Trends Neurosci . 2014 May;37(5): 264–278 , Zebrafish (2010): 289-295 and Virginia Cooperative Extension (2019): 105