Not long ago, I was having a conversation with my friend Jim Burris, who is not only an avid bass fisherman, but a fish biologist at Duke University Medical Center. At the time I was just getting over a cold, most likely picked up from a shopping cart handle or something. This led us to a discussion about his studies on small tropical zebrafish. His work is aimed at helping us better understand immunological responses in humans, because fish were the first to develop an adaptive immune response, and thus contain valuable clues into the development of the immune system in people. Me being me, I immediately figured out how I could use Jim’s fishy knowledge to learn something new about bass.
I asked Jim how bass get sick, how that sickness spreads, how they handle a “cold” vs. how a human handles a cold, and if there’s anything anglers can do to help a sick bass. At some point, it’s likely you’ve run ill-looking fish that wouldn’t bite, or caught a bass that just looked…well…sick. Some of you may even have a lake nearby that has experienced the spread of the largemouth bass virus (LMBV), which you can read more about here. Jim said that the most obvious thing we can do to help a bass that looks sick, or keep them from getting sick, is handle them as carefully as possible, and by paying attention to stressors like rough live well rides with multiple fish, oxygen levels, and water temperature. He noted that bass may already have subclinical infections that only manifest when the fish is stressed. That part is pretty similar to humans; we may be carrying a virus, but may not get ill until we have a stressful day at work and get just three hours of sleep.
It takes a bass four to six weeks (depending on water temperature) for their adaptive immune responses to produce antibodies specific to the antigens on a virus’s surface, as opposed to humans where it takes only about two weeks. That virus-fighting process is critical to thwarting the spread of infection, and subsequent reinfections in both bass and humans. But humans can fight an illness more effectively than bass because of the quick response of our adaptive immune system. Bass put more energy into their innate immune responses and try to prevent infection from ever occurring in the first place. In other words, they spend more to fighting to avoid the fight entirely. It’s not a bad system, but it means if they do get a virus, they may not get it under control fast enough or 100% effectively.