Reproductive patterns in the deep-sea benthos

The reproductive condition of a variety of benthic invertebrates from the bathyal San Diego Trough was monitored periodically. In this physically seasonless, deep-sea environment most species reproduce throughout the year, and only a few display highly synchronous, annual reproductive cycles. These few are not typical deep-sea species; they are known from shallow water and belong to groups which are relatively unimportant in abyssal depths. Of the 11 species examined, 3 bivalves, 2 ophiuroids, 2 isopods, 1 amphipod, and 1 polychaete breed year-round, and 1 brachiopod and 1 scaphopod spawn seasonally.