Reproduction and dispersal at vents and cold seeps

Reproductive cycles are determined from samples taken at regular intervals over a period of timerelated to the assumed periodicity of the breeding cycle. Fiscal, ship time and sampling constraints havemade this almost impossible at deep-sea vents and seeps, but there is an accumulating mass of data thatcast light on these processes. It is becoming apparent that most reproductive processes are phylogeneti-cally conservative, even in extreme vent and seep habitats. Reproductive patterns of species occurring atvents and seeps are not dissimilar to those of species from the same phyla found in non-chemosyntheticenvironments. The demographic structure of most vent and seep animals is undescribed and themaximum ages and growth rates are not known. We know little about how the gametogenic cycle isinitiated, though there is a growing body of data on the size at first reproduction.