Nancy Knowlton's blog

If youngsters get cared for at all, the mother is usually involved. But in fish and a few other groups where eggs are not abandoned, fathers are the primary care providers. Males are sometimes such devoted dads that it takes longer for them to care for the young than it does for the females to produce the eggs. If potential fathers are in limited supply, stereotypical male and female roles get reversed, with males more interested in food and females more interested in sex.

Last September, the Citizens of the Sea blog series brought you a story of doom and gloom from the reefs of Bocas del Toro, Panama. That is the time of year we typically study -- and celebrate -- the annual birth of baby corals in the area. We arrived to find very hot water (2010 turned out to be the hottest year on record), and in the shallows the reefs had turned a ghostly white. This was the most extreme coral bleaching we had ever seen since we started our studies there in 1998.