The Mudcat idea originally came about from the acronym for the project. Multi-User Droplet Combustion Apparatus (MUDCA) and I simply added the Team part for it to become a logo for those working on the MDCA project.
Being a Cleveland Indians fan I was aware of mudcats (the fish) from a former pitcher, being Jim "Mudcat" Grant; quite a character. Anyhow the fish concept came about that way, the red ball symbolizes a burning droplet of liquid fuel, which was the purpose of the hardware.
Original versions had just the fish and droplet, but a Branch Chief who was an avid fisherman recommended adding the hook and thus the swirling part of the logo to support the hook inclusion.
On the backing to the sticker of the logo is the following text:
"The Multi-User Droplet Combustion Apparatus Team (MUDCAT) is designing a facility to be used by combustion scientists aboard the International Space Station as a platform to study various phenomena of droplet combustion. The Multi-User Droplet Combustion Apparatus (MDCA) will be integrated into the Fluids and Combustion Facility's Combustion Integrated Rack (CIR). Experiments supported include: Droplet Combustion Experiment (DCE), Bi-Component Droplet Combustion Experiment (BCDCE), Sooting and Radiation Effects in Droplet Combustion (SEDC), and Dynamics of Droplet Combustion and Extinction (DDCE). This logo depicts the MUDCAT aggressively pursuing a burning droplet representing data for the science community."
An interesting aside, many people did not support the logo; they felt it projected a negative impression of the project by featuring a 'bottom-feeding fish'. But eventually it found the right support and went forward.
The MDCA is currently on-orbit, integrated into the CIR aboard the ISS. It is conducting science for an experiment called FLEX right now, which stands for Flame Extinguishment Experiment that uses droplets of liquid fuel.
Thanks for your interest. Hopefully you find some of this interesting and helpful!