Researcher: Fish First to Have Intimate Sex

So much for the term "cold fish."

Turns out that fish first began been having sex through copulation some 400 million to 410 million years ago, according to a scientist cited by Discovery News.

This was "not just spawning in water," said John Long, vice president of research and collections at the Natural History Museum of Los Angeles County, "but sex that was fun."

Long's research was based on fossils of extinct armored fishes found in the Gogo Formation of Western Australia.

He also suggested a different chronology in the evolution of fish jaws. "Jaws might not have first evolved for feeding, as widely presupposed, but to facilitate copulatory mating," he said. "In many sharks the jaws are used to hold on to pectoral fins of females so copulation can take place."

Long was previously Head of Sciences at Australia's Museum Victoria. In 2008, Long announced what is thought to be the world's oldest mother, Materpiscis attenboroughi, a 375 million year old placoderm fish with embryo and umbilical cord attached, named after the famous naturalist Sir David Attenborough.

Speaking with Discovery News, he said:

"Our finds show that these extinct armored fishes, the placoderms, had intimate copulation with males inserting claspers (a structure that is part of the pelvic fin) inside the female to deposit sperm." He added that the find "is significant because it means that an advanced form of reproduction involving copulation and live-bearing was more widespread than previously thought...It seems that limbs and genitals developed via the same developmental pathways, so fossils showing the oldest evidence of pelvic fins (the placoderms) also showing the oldest expression of sexual organs (claspers) might not be such a coincidence."

Long's research was officially presented at the annual meeting of the Society of Vertebrate Paleontology taking place this week in Pittsburgh.