Deep-Sea News links to an article in the Seattle PI on Ted Pietsch, the expert on deep sea angler fish and their peculiar sexual practices—these are the fish in which the male is tiny and permanently attached to the female, a condition that guarantees males won't lose their mate in the inky and sparsely populated deeps. Deep-Sea News also has some useful diagrams illustrating the diversity of forms in the Ceratiodei.

Thanks to Chris for providing the lovely photo.