Biologists witnessed an array of complex mating behaviours as they snorkeled two meters or less above the shallow reefs of northern Sulawesi in Indonesia. For several weeks, they tracked Octopus Abdopus aculeatus, a diurnal species of cephalopod that typically sports a spiky tan body the size of a small orange and 8-to-10-inch-long sucker-lined arms. ''This is not a unique species of octopus, which suggests others behave this way,'' a professor of integrative biology at UC Berkeley and co-author Roy Caldwell said.
Researchers observed exemplary romantic tendencies of macho octopuses that didn't just mate with the first female that crossed their path but also picked out a specific sex partner. They even jealously guarded her den for several days, warding off rivals to the point of strangling them if they got too close.
When flirting or fighting, they would signal their manliness by displaying striped body patterns.
''If you're going to spend time guarding a female, you want to go for the biggest female you can find because she's going to produce more eggs,'' Caldwell said adding, ''It's basically an investment strategy.''