Looking Up -- Fish that Live on the Bottom
To keep things simple when providing information to anglers, to help them be better fisherpeople and better stewards of the environment we all love and share, the editorial department of The Online Fisherman often break things into threes.
There are three primary categories of fishing rods: spinning, bait casting (or conventional) and fly-rods. Another thing that comes in a triplet is the major categories of feeder fish. They are termed, Inferior, Terminal, and Superior. The Inferior feeders are the ones whose top jaw is longer than the bottom, for example, redfish or catfish.
Their mouths are shaped so it is easier to pick up food from underneath. The second type, which are Terminal feeders, have upper and lower jaws the exact same length. For example, when mackerels and tunas chase baits in open water, the bait is usually in front of them. They feed on running baits and they get directly behind them before they eat them. The third type, the Superior feeders, mostly look up towards the water's surface. Their bottom jaws are considerably shorter than their tops. These Superior feeders, such as Largemouth bass, tarpon and snook, are more likely to hit a bait above them than a fish that feeds mostly on the bottom, or chases schools of smaller fish swimming in open bays or oceans.
Superior feeders such as Largemouth bass look up to feed, just like snook or tarpon. Bonefish, redfish, catfish, etc., look down. Mackerel like the Kingfish (middle image) are called Terminal feeders – they look in front of them and normally chase schools of smaller baitfish in open water, where teams of the predators circle them to the surface, where you see birds eating the baitfish. But grouper – considered a bottom fish – are superior in structure. And how about flounder? They are shaped like a superior but their density and form keeps them directly on the bottom – under the sand in a lot of cases to better hide from their prey.
A Fourth Category of Feeder?
Whenever we teach this concept – that some fish look down, some watch the water in front of them, and others look up – there are always a few doubts that enter into the fray. We also talk about the three types of fish when we talk about another triplet: Artificial lures. Some lures are meant to bounce on the bottom (jigs), some are meant to swim in the middle of the water column (spoons and swimming plugs) and others – topwaters – are meant to splash, gurgle, or otherwise disturb the surface. The doubt that enters our head is related to bottom feeders. Some of them – a grouper for example -- are on the bottom all the time. But they are bottom dwellers whose bone structure means they are looking up, not down. That is why you'll get more hits if you keep your grouper baits slightly off the bottom. "Let it hit the bottom and then take it back up a few feet," is common advice from experienced grouper diggers like our own Vance Tice.
Another questionable structure category is the flounder. They actually lay on the bottom and their eyes – both of them – are on one side looking up. The structure of their mouth – which clearly shows their top jaw considerably longer then the bottom jaw – makes them Superior feeders. But when they're waiting for something to swim above them, they're so dense and heavy relative to water, that density keeps them pinned down.
Demersals: Superiors or Inferiors?
The fourth category of fish – the Demersal species – can be found in both superior and inferior models. Catfish – the gaff topsail or hardheads we catch in saltwater, or the tasty channels we eat from freshwater – are clearly inferiors. They live on the bottom, and they eat stuff they find there. Grouper – the bottom dwellers we buy at restaurants and pay tons of money to catch – live on the bottom but look up. Rays are another of the fish we often catch that live almost stuck to the bottom. A catfish will hit a lure, and grouper can be caught in 12 feet of water here on the Gulf, at times acting for all the world like largemouth bass. Their mouth structure is almost identical – bottom jaws considerably shorter than the top and their mouths at a forty-five degree angle. Channel catfish are not the only edible ones we catch. Sometimes try skinning, cleaning, and baking or frying a Gaff Topsail. You might be amazed at the flavor and texture of their clean white meat.
Density of the Target Species
Benthic fish, sometimes called groundfish, are fish that live on or near the bottom. They can, as we said, be different categories of feeders. They are found, however, down in the lowest water column. The ones that live actually lying on the bottom most of the time – the flat fish like flounders or the bottom feeders like catfish – will often hit a bait off the bottom. Grouper and a lot of the snappers too – live in caves or near and around bottom structure. You can literally see grouper and snapper come off the bottom slightly as they actively feed, and see them disappear on the bottom finders when the bite is over. Literally, they come up only to eat, and otherwise sit with their bottoms on the bottom.
The dense fish are called Benthic fish. Their body density is heavier than the water so they are pulled down by gravity. The others that live there such as grouper but feed upwards – are called Benthopelagic – can float in the water column because their density relative to the water is neutral. Some fish are actually slightly lighter than water, and therefore stay very near the surface of the water.
Catching Bottom Feeders
Scientific and Latin aside, what does this mean to the angler? Quite a bit. If you want to catch a flounder, try slow-dragging a jig and lifting it off the bottom on the retrieve. The fish will often hit on the lift or drop, and now when the jig is dragging. Grouper are another super example of matching the lure or bait to where the fish is likely to be. A torpedo cork on a fish-finder for example, will lift the baits slightly off the bottom, where bottom dwellers like grouper or snapper are more likely to see them.
The next time you attend a seminar, you might hear more about the Superior flounder or Inferior channel catfish, but always remember that the density of the fish is a big determining factor in where you will find your target and how to best present the baits you're bringing.
Tight lines ...