Have you ever wondered why red drum make a drumming sound? Do you know why redfish have a spot on their tail? How far do drum migrate? How old do they get? How big can they grow? Why are redfish red? Do they recognize their friends and family members?
After more than three decades chasing redfish, my friends and I have asked these questions and more. To find the answers, I reached out to the experts.
Dr. Susan Lowerre-Barbieri is a research professor at University of Florida and research scientist at the Fish and Wildlife Research Institute. Her many projects include research on the connection between drumming and spawning.
Dr. Sean Powers is director of the school of Marine Sciences at the University of South Alabama and a senior marine scientist at the Dauphin Island Sea Lab. His research focuses on the ecology of marine fish and invertebrates, particularly those that support commercial and recreational fisheries.
I asked the experts and they answered. Surprisingly, most of our questions have scientific research. Some redfish myths and mysteries will remain unknown.
Why do redfish have a spot on their tail?
Dr. Sean Powers: The spot is likely a predator defense strategy. Predators would clue in on the spot thinking it is an eye. The predator strikes the back of the tail, where it is likely to miss the redfish or do less damage.
The spot is what we call an ocellated spot with a dark center, white mid circle and a black outer circle. The pattern is similar to an eye. The spot is so characteristic of the species, that the redfish’s Latin scientific name is Sciaenops ocellatus (the latin word ocellus translates to little eye).
Why do some reds have multiple spots or unique spot patterns?
Dr. Sean Powers: Multiple spots are probably just random mutations and don’t offer any advantage.
To our knowledge, red drum do not recognize other individuals. There is really no evolutionary benefit to recognizing each other since the fish are group spawners.
Does a red drum’s spot pattern change over time?
Dr. Sean Powers: Spot pattern doesn’t change much over a redfish’s life. The size and shape of the spot is set but some smaller spots may disappear.
Why do redfish drum?
Dr. Susan Lowerre-Barbieri: Drumming is associated with spawning and becomes more rapid and with more “knocks” as fish get closer to a spawning event. We observed this in-captivity.
Do male and female reds drum? At what age do they start drumming?
Dr. Susan Lowerre-Barbieri: Only males drum. Sonic muscles have been reported in males as young as 9 months, but they are not believed to become functional until the fish mature.
How do redfish make a drumming sound?
Dr. Sean Powers: The sound is produced by the swimbladder which is well developed in this family of fish. The swimbladder is the shiny white sack you see when you clean a red drum. It can greatly expand in size.
How do age and length correlate for redfish?
Like many fish species, the largest “bull” redfish are predominantly female. However, male and female redfish appear to grow at similar rates.
Dr. Susan Lowerre-Barbieri: In the 10,000 adult red drum that we non-lethally sampled off Tampa Bay, females and males are similarly sized. Mean-size of males was 35.3 inches and mean size for females was 35.7 inches.
How old is a slot redfish?
The size limit for red drum varies depending on the fishery, but most are managed under a slot limit that allows anglers to keep fish between a minimum and maximum length inches. According to Dr. Lowerre-Barbieri, a red drum between 18 and 27 inches is 2 to 4 years old.
How old do red drum get?
Dr. Susan Lowerre-Barbieri: The oldest drum sampled in Florida was 35 years old. Red drum older than 50 years have been sampled off the Chesapeake Bay.
How far offshore do redfish migrate?
Dr. Susan Lowerre-Barbieri: We have tracked them over 50 miles offshore of Tampa Bay. Some fish as young as age 2 recruit to open water.
When and where do red drum migrate?
Dr. Sean Powers: Once red drum are reproductively mature, most will spend a large part of their lives offshore. But it’s really better to consider nearshore waters 0 to 12 miles from the beach with the vast majority within 3 to 6 miles. Most of our data from tagging studies does not suggest large scale movement is very common. Most red drum stay near the estuary where they grew up. Major hurricanes result in greater movement. There is enough large-scale movement across the Gulf to make it a very genetically homogeneous population. We are trying to resolve how much interstate movement occurs with a study to look at the issue supported by the CCA.
Do bull redfish return Inshore?
Dr. Sean Powers: Just because redfish move offshore to spawn and feed doesn’t mean large reds don’t spend time in the bay. Some older fish will split time and go back inshore. The big red drum schools move offshore in April-May and August-November. The latter schools form because of reproduction. Redfish in the April schools are not reproducing, so they must be gathering to feed.
Why are redfish different colors?
Dr. Sean Powers: We know that diet and habitat, not so much salinity, influences coloration. We see red drum that are very silver to copper color. The tail sometimes has a brilliant blue hue. We don’t know enough to predict which habitat and diet combinations produce which colors. In fact, your readers probably know more. Collectively, anglers have more field observations. But we know diet, which reflects habitat type, influences thyroid hormone levels. In captivity, thyroid hormone levels influence coloration.
Do drum over 40 inches weigh 1 pound per inch?
Dr. Sean Powers: Length and weight really varies. But, a pound per inch over 40 inches is a safe rule of thumb. Generally, fish in better condition have greater weight per unit length.
Can redfish live in freshwater?
Dr. Susan Lowerre-Barbieri: Juvenile red drum are often sampled from freshwater sections of coastal rivers.
Are saltwater drum and freshwater drum related?
Dr. Sean Powers: Freshwater drum (Aplodinotus grunniens) are in the same family Sciaenidae (as saltwater red drum). They are the only Sciaenid in North America that are freshwater.
