COLUMN : BASS SCIENCE
THE HYDRODYANAMICS OF A BASS
To get better at catching bass , you first have to understand how they ’ re built to move
ILLUSTRATION BY MATT PACE
B y most credible accounts , there are roughly 30,000 species of fish on this planet , with more being discovered each year . Within that cohort you ’ ll find fish of all shapes , sizes , colors and temperaments . From the miniscule dwarf pygmy goby ( sexually mature at a whopping 0.35 inches ) to the massive 15-ton whale shark , fish are truly amazing creatures .
Despite all that variability , most fish share a pretty similar body plan and swim mechanics using the propulsive force of specialized appendages called fins , laid out in a similar fashion across most species .
As for our favorite fish species , the black basses ( largemouth , spotted bass and smallmouth ), physically they ’ re rather unremarkable . They ’ re not particularly big , fast or aggressive . Heck , as handsome as the brown mottling is on the back of a bruiser smallmouth , bass are quite drab when put against some of the eye-popping colors found on just about any reef in the Caribbean .
It ’ s that “ everyman ” quality about bass that makes them special , and it also makes them a great analogue for a discussion on how fish use their fins to swim , as well as a deep dive into the way their fins lay out and how they use them to feed .
Body Shape
You can learn a lot about how a fish lives just by looking at its body shape . Longer and narrower ( think tuna , sailfish , mackerel ) is best for speed and open-water roaming ; shorter and more vertically compressed ( think bluegills , crappies , angelfish , pompano ) is ideal for rapid maneuvering and quick turns . Bass body shape speaks to their versatility . They ’ re streamlined and sleek , capable of cruising and effectively chasing down shad in open water , but they ’ re also vertically compressed enough to make quick turns and rapid direction changes – which comes in handy chasing bream through a pad field .
Pectoral Fins
Think of the pectoral fins as the predominant steering mechanism on most fish . Found along the side of the fish just behind the gill opening , fish use pectoral fins as planers to dive or climb , use them in tandem to turn , and also to back up . Pectoral fins come in a huge variety across fish species , with tons of specialization depending on where and how a fish lives .
Flying fish , for example , use extremely large and specialized pectoral fins to glide through the air for up to 150 feet to escape predators . Rays and skates also use heavily modified pectoral fins for swimming – using them like wings to move about . In bass , the pectoral fins are the primary finemovement thrusters . Watch a bass just hanging out , and their pectoral fins are constantly making fine adjustments to keep them stationary or move them in small precise ways ( perhaps keeping a close eye on a school of baitfish or your shimmying trick worm ).
Pelvic Fins
In bass , the pelvic fins are the pair of fins located on their ventral ( bottom ) surface , just behind the head . They ’ re used primarily for precision movements and slight adjustments in position . You can see a bass ’ pelvic fins working often when they ’ re looking at a lure that landed on their bed .
20 MAJORLEAGUEFISHING . COM | FEBRUARY-MARCH 2021