Sex on the Reef - Reef Life of the Andaman - Part 24

In this video we look at how some marine species breed underwater. First we look at broadcast spawning, whereby marine animals release sperm or eggs, collectively known as "gametes", into the water. Large amounts of spawn are released to maximise the chances of successful fertilisation in the open water.

We see a Graeffe's sea cucumber, Pearsonothuria graeffei, broadcast spawning at Racha Yai near Phuket in Thailand, as well as a pizza anemone, Cryptodendrum adhaesivum, and a cock's comb oyster, Lopha cristagalli, in Burma's Mergui Archipelago. Pharaoh cuttlefish, Sepia pharaonis, are one of the most intelligent marine creatures. They copulate face to face, using their ten tentacles to embrace. The male cuttlefish passes spermatophores into a pouch beneath the female's mouth. He may first use a jet of water to flush out the spermatophores of any previous mates. Scuba divers may approach closely while the couple are engrossed in mating. After copulation the female cuttlefish passes her eggs over the sperm and into a crevice in the rocks. The male is extremely protective over the female and aggressively fends off other male suitors. Finally, at Shark Cave, we see a male bigfin reef squid, Sepioteuthis lessoniana, escorting a female as she deposits her eggs in the coral reef.