Reproductive ecology of three reef-forming, deep-sea corals in the New Zealand region

Reproductive ecology was examined in three deep-sea, reef-forming corals, Goniocorella dumosa, Solenosmilia variabilis and Enallopsammia rostrata from the 'Graveyard' seamount complex on the Chatham Rise, New Zealand. Samples were collected from 890-1130 m depth in April 2001 using an epibenthic sled from the research vessel Tangaroa. S. variabilis was found to be gonochoric and this sexual trait was also suggested for E. rostrata and G. dumosa, although only colonies of one sex were collected. The likely mode of reproduction is broadcast spawning and fertilisation is likely to occur in late April or May coinciding with pelagic biomass accumulations at the end of summer. Reproductive development displayed a high level of synchrony among species and between seamount localities. E. rostrata was observed to contain both stage III and stage IV oocytes, indicating overlapping cohorts of oocyte growth, possibly related to food resources available. High fecundities were estimated for E. rostrata (>144 oocytes polyp(-1)), G. dumosa (>480 oocytes polyp(-1)) and S. variabilis (>290 oocytes polyp(-1)), with a negative correlation between oocyte size and number observed for all three species.