Echinodermata
Echinoderms are a phylum of water animals. They resemble the shape of starfish,
having five points. They thrive at very low ocean depths.
having five points. They thrive at very low ocean depths.
Ophionereis reticulata
Ophionereis reticulate reproduce by regeneration of limbs, if one is lost it will grow back. There are males and females in Ophionereis reticulata and spawning takes place once a year. The ophiopluteus larvae are microscopic and after passing through several early larval stages, settle on the seabed and undergo metamorphosis. Strongylocentrotus purpuratus Purple sea urchins breed yearly after two years of age. They reproduce through external fertilization during which males release their gametes into the ocean and fertilize the female’s eggs at random. The water aids in the transportation of the gametes. After fertilization, the egg matures and grows into a sea urchin. Sea cucumbers Most sea cucumbers reproduce by releasing sperm and ova into the ocean water. Depending on conditions, one organism can produce thousands of gametes. Sea cucumbers have both male and female individuals, but some species are both. The reproductive system consists of a single organ, consisting of a cluster of tubules emptying into a single duct that opens on the upper surface of the animal, close to the tentacles. |