Lecturer discusses sex lives of spiders

If you want to have children, be prepared to sacrifice your dignity, abdomen and ultimately your life -- that is, if you're an Australian redback male spider. \nThe close-cousins of the notorious cannibalistic black widow, redback males throw themselves onto the fangs of the females during their mating ritual -- and become partially consumed from the abdomen out during the deed. \nIt's an act that Canadian zoologist Maydianne Andrade finds fascinating enough to base her career around.\nAndrade, the fifth annual featured lecturer of the James P. Holland Memorial Lecture series, spoke Monday about her passion for the spiders, which, as she says, have pretty unique mating acts.\n"It's absolutely astounding behavior," Andrade said, taking the audience through a ritual which included spider somersaults, "sperm plugs" and ultimately, cannibalism of the male by the female redback.\nAndrade's lecture, called "Between a Rock and a Hard Place: Evolution of Self-Sacrificing Male Mating Behavior," explains the behavior of each gender. The "rock," as she explains, is the female -- "She can demand anything," said Andrade. The "hard place" is the ecology of the system, in which the life of the male redback is fully focused on this one mating. After that, he's spent.\n"They've got to put all their eggs in one basket," Andrade said. \nShe's not kidding, either.\nAndrade studies the "why" of the redbacks' mating ritual, and her lab is trying to discover the biological reasoning behind the act. \nFrom her research, she has hypothesized that the cannibalization that occurs during the mating act works to the benefit of the male, as females will hold still during the mating if allowed to cannibalize the male -- increasing the male's chance of fully emptying his sperm palps while in the somersault position required to join with the female. \nCannibalized males also have a higher chance of getting a "sperm plug" in place -- a portion of the coil from which redbacks release sperm to block other male sperm from entering a sperm receptacle -- than non-cannibalized males do. \nRedbacks simply don't have too many other options to spread their seed successfully other than allowing the female to cannibalize them -- and though their lives are quite short and brutal, they're quite purposeful. The grow, mate and die -- but their genes are passed on.\n"And I thought biology was boring!" quipped Associate Vice Chancellor Frank Motley, who introduced Andrade.\n-- Contact health and science editor Kelly Phillips at kephilli@indiana.edu.