Louisiana sawfish are just memories

It’s not likely that many Louisiana coastal anglers give sawfish a thought. In fact, it’s not likely that anyone under the age of 50 even knows we ever had a sawfish population in the state.

Even fewer people have seen one.

I remember them well. When I began my biologist career at LSU in 1976, they were still common enough that commercial shrimpers and gill netters would sputter at the mention of one of these often huge, powerful creatures with their long snouts studded with sharp, bone-hard teeth coming up tangled in their nets.

It happened often enough that virtually every commercial fisherman had to deal with them. Sportsmen caught their share, too, most often when fishing with cut bait for other species.

Both recreational and commercial fisherman shared one habit: They hacked or sawed the bills off the fish as souvenirs before “releasing” them.

I remember the last one I saw — a 20-footer caught with a Delacroix gill net in the early 1980s. It was lying on the concrete floor of Battistella’s Seafood on Touro Street in New Orleans.

It had wiped out the net, and since the monster was longer than the fisherman’s boat and still kicking, he had no choice but to tow the net-ball and fish to the landing behind his boat.

He hoisted the beast into his truck and hauled it to Battistella’s, hoping for a sale that would cover part of his loss on the destroyed net. He was disappointed; there was no market for sawfish.

I got the fish’s bill before it was carted away.

The smalltooth sawfish, Pristis pectinata, is one of seven sawfish species that occur worldwide in tropical and subtropical coastal waters, rivers and lakes.

The genus name Pristis, is Greek and means “saw.” The species name pectinata, is Latin for “combed.”

Smalltooth sawfish were once found from New York to Brazil, including the entire Gulf of Mexico and the Caribbean Sea. The biggest stronghold for the species was southern Florida, followed by the coastal waters of Southeast Louisiana.

Most scientists now believe sawfish captured north of Florida along the Atlantic coast were not resident fish, but rather wanderers that strayed northward from May to August as water temperatures warmed. The lower temperature limit for the species appears to be 61 to 64 degrees Fahrenheit.

The sawfish species geographically closest to the smalltooth sawfish is the largetooth sawfish, Pristis perotteti.

Largetooth sawfish are a more tropical species, but have been recorded as far north along the Texas coast as the state’s border with Louisiana.

The two species are relatively easy to tell apart. Smalltooth sawfish have 20 to 29 teeth on each side of their bills, compared to the 20 or less for the largetooth sawfish on their much-broader bills. Another distinguishing feature is that the smalltooth sawfish has no lower lobe on its tail fin.

Largetooth sawfish have a pronounced and noticeable fin lobe.

Smalltooth sawfish are elasmobranches, the class of fish to which all sharks and rays belong. Sawfish resemble both rays and sharks. The front of their bodies is flattened like rays’ bodies. The rear of their bodies is elongated and roundish in cross section, like that of sharks.

Their mouths give them away as actually being a ray rather than a shark. The square “trap door” mouth holds teeth similar to rays, being designed more for crushing than for cutting. Each tooth is flattened and rounded, although it has a cutting edge on the rear of the tooth.

In spite of its crushing teeth, the primary food item for smalltooth sawfish are small, schooling fish such as mullets, herrings and menhaden. They attack these fish by slashing their bills sideways through schools, spearing them with the teeth of their bills.

They remove these to eat them by scraping them off on the water bottom. They also use their bills to disturb muddy bottoms in search of bottom-living creatures such as shrimp and crabs.

As with all sharks and rays, fertilization is internal, with the male transferring sperm to the female with modified pelvic fins called claspers. Fertilized female sawfish hold their eggs internally until they hatch and the young use up their yolk sacs.

Newly born smalltooth sawfish are about 31 inches long and come into the world with soft and pliable saws, and teeth enclosed in sheaths that protects the mothers during the birthing process. Litter sizes are listed as being between 15 and 20, and the young are born during warmer months of the year.

Very young sawfish are susceptible to sharks, so they spend most of their time on mud or sand banks in water less than 1 foot deep. As they grow, they use slightly deeper water, but until 6 to 7 feet long still spend most of their time in waters less than 3 feet deep and move very little from their home bases.

Adult sawfish, which average 18 feet long but can grow to 25 feet, will use deeper waters, up to 400 feet deep, although they are usually found in waters shallower than 32 feet. At all sizes, mud bottoms are preferred by smalltooth sawfish.

The species also seems to have a preference for river mouths and other low-salinity areas. They have been recorded in 1820 as far up the Mississippi River as the Red River in Arkansas. This and the animal’s preference for mud bottoms explain why Louisiana was once prime habitat for the species.

The last stronghold for smalltooth sawfish in the United States is southern Florida, primarily the Everglades National Park area. Most experts blame fishing encounters, especially entanglement in nets as the reason for the creature’s decline in numbers.

Other factors negatively affect sawfish numbers, including agricultural runoff, urban wetland development (mainly in Florida), discharges of warm water and pollution from industries, marsh loss (especially in Louisiana), and channel dredging that destroys shallow-water habitats.

Smalltooth sawfish are now fully protected. In 1999, the Ocean Conservancy petitioned for listed the species under the Endangered Species Act. This was done on April 1, 2003, making it the first marine fish species to be listed as endangered under the act.

Smalltooth sawfish grow slowly, are late-maturing and long-lived, and produce few young, so population growth will be slow. By one estimate, males must be 19 and females 33 years old before spawning. Sawfish might live 60 years.

The most-current population assessment, done from 1989 to 2004, shows their population growing at about 5 percent per year. It is estimated that recovery to point that the animal occupies its former range, including Louisiana, will not occur until the 2106 — 91 years from now.

About Jerald Horst 959 Articles
Jerald Horst is a retired Louisiana State University professor of fisheries. He is an active writer, book author and outdoorsman.

Be the first to comment

Leave a Reply