The largest sawfish that scientists have ever measured was found dead in the Florida Keys last week.
The 16-foot-long (4.9-meter) sharp-snouted fish was an adult female with eggs from the soft balls found in her reproductive tract. Scientists are now studying her carcass to determine her age and to learn more about her reproductive past.
“Although it’s a sad event when such a large animal dies, we knew from a scientific point of view that we could learn a lot from it,” said Gregg Poulakis, a fish biologist with the Florida Fish and Wildlife Conservation Commission. “It makes us feel a little better when we’ve lost such a great woman.”
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Sawfish study
The record-breaking sawfish was one of two dead sawfish that washed ashore in the Keys last week, one near Cudjoe Key and the other near Marvin Key. They were found far enough apart that the timing of their deaths was probably accidental, Poulakis told WordsSideKick.
Citizens reported the fish via the Commission’s hotfish hotline, and local law enforcers helped drag the carcasses to shore so researchers could measure them and take tissue samples. Sawdust has been on the commission’s research radar since 2003, when it was added to the US Federal List of Endangered Species. (All five species of sawfish are also threatened or critically endangered by the International Union for Conservation of Nature.)
Sawfish are a type of jet fish known for their flat, chainsaw-like snouts. Little was known about them before they endangered species Poulakis said.
‘Actually, you would ask any questions:’ How big are they ?; What kind of habitat do they need? how long do they live ‘- we just did not have an answer, “he said.
Now catch, mark and release sawfish regularly along the coast Poulakis and other associates within the Commission and other research agencies in Florida. They also get about 20 to 30 reported sightings per month from boat fishermen and anglers. Five or six times a year a dead sawfish washes ashore. Even carcasses that have partially decomposed are scientifically useful, Poulakis said: Rays’ vertebrae show a growth limit every year, just like a tree trunk, so by cutting the bone and counting the lines, scientists can tell how old the animal is. was when he died. .
A Sawfish Matriarch
The oldest sawfish studied so far by the Poulakis team was 4.7 meters long and 14 years old. The smaller of the two sawfish found dead last week was 3.8 meters long and was still a juvenile, Poulakis said. She had immature eggs in her ovaries. The 16-foot sawfish, on the other hand, was a full-grown adult.
“We are excited to see how old the 16-footer we got this week is,” Poulakis said last week. ‘I think it’s that she’s older than [14]. “
The two sawfish had no injuries or other indications as to why they died, Poulakis said.
The researchers study the reproductive channels of the fish to understand more about when they reach adulthood. Sawfish pregnancies last about a year, Poulakis said, and they give birth to live pups about 0.7 meters long.
The researchers also plan to take it DNA samples, which they can compare with the DNA of the young sawfish they catch to look for relationships along the mother line. They will also examine the parasites’ animals to understand the parasite load in the body of a sawfish.
Anyone in Florida who sees a sawfish should report the sighting to the state’s fishfish hotline, Poulakis said. Observations can be reported by phone at 844-4SAWFISH, by email at [email protected], or via the FWC Reporter app.
Originally published on Live Science.