Fantastic Metropolis

Smythe, a traveling salesman from Palatka, Florida, disproved this theory using a bucket and an aquarium. An avid fish enthusiast and a member of the local chapter of the Freshwater Fish Association, Smythe liked to fill buckets with Palatka River water and strain out any likely-looking food for his fish. One day in May of 1944, Smythe caught a “cluster of what looked like tiny insect larvae, each with a hook on their end.” That afternoon he fed the “larvae” to his neon tetras, guppies, and angelfish, left further feedings to his sister, and set off on a ten-day circular sales trip through the small towns of north-central Florida.

Upon his return, Smythe found most of his fish eaten and the remainder in a tense stand-off with a “half-dozen graceful, jelly-like creatures with luminous eyes.” Smythe quickly consulted his Field Guide to Aquatic Life of the Southeastern United States, but the 1947 edition did not contain any mention of the mayfly squid-or anything that looked remotely like his intruders. It took a telephone call to Dr. Sarah Willis at the University of Texas’ National Cephalopod Institute (Galveston, Texas) three days later before he understood what sort of creature had magically appeared in his tank. (15)

Although Smythe subsequently passed out of history, eventually retiring to run a Palatka bait shop, his contribution proved perhaps more enduring than Dr. Johnson’s ten years of studies.^[8]

An Overview of the Mayfly Squid’s History, Physiology, and Habits

The Mayfly Squid’s Introduction into the United States

Origins

The most plausible theory for how the mayfly squid reached Florida’s lakes and rivers speculates that juvenile “lula brasileira de agua fresca” or Brazilian freshwater squid (Fons brasiliensis)^[9] arrived in Miami or Tampa via ships of South American Registry. Since Brazilian freighters have docked at South Florida ports since the 1870s,^[10] it is not improbable that squid young could have made the journey to the United States in water that collected in cargo boxes, a sailor’s shoes, or even a half-closed umbrella. (16)

An alternate theory relies on known cases of travelers purposefully bringing foreign species into the United States.^[11] If this is the case, then the mayfly squid may have entered the Florida ecosystem when someone grew bored with their exotic acquisition and dumped a tank of adult and/or juvenile squid into a lake or stream.

Regardless of the entry method, a connection does seem to exist between the Brazilian and Floridian squid. Yale University’s Charles Sibly studies the biochemical binding possible between the DNA of different species. The more two species bind at the DNA level, the closer the relationship between them. In the case of the Brazilian and Floridian freshwater squid, Sibly reported a 94% match-proof of a connection between Fons brasiliensis and Fons volatilis, but not conclusive enough for Fons volatilis to be reclassified as Fons brasiliensis volatilis. (17)

Dispersal

Once the mayfly squid became established in the Florida ecosystem, the state’s natural weather patterns conspired with the juvenile squid’s natural hardiness to facilitate range expansion. Sandra Westwood’s 1989 study “The Response of Mayfly Squid Juveniles to Adverse Conditions” demonstrates that the squid larvae can survive for weeks surrounded by only a thin protective bubble of water. In such circumstances, the squid’s normal growth cycle slows or halts altogether until a larger water source impacts upon it. (18)

The squid’s reproductive cycle results in fertilization of the female sometime between May and July, followed by the birth of the young squid six weeks later. This cycle coincides with Florida’s May-to-September hurricane season. As a result, flooding due to heavy rains has helped spread the mayfly squid from south to north Florida and beyond.^[12]

Another dispersal method facilitated by heavy rains provides further circumstantial evidence for the Brazil-Florida link and also explains the temporary hook found on the juvenile’s mantle.

The Brazilian freshwater squid will, whenever possible, enter into a symbiotic relationship with the Giant Amazonian catfish (Pteronura brasiliensis) by giving birth in their vicinity.^[13] The catfish will eat some of the young squid, but the majority use their hooks to find safety on the sides of the catfish. Over the next four to six weeks, they will scrounge scraps left over from the catfish’s own scavenging and reward its host by eating any parasites that settle on the catfish’s skin. (19)