Jellyfish diameter; the tentacles and mouth parts usually extend beyond this bell dimension. The smallest jellyfish are the peculiar creeping jellyfish in the genera "Staurocladia" and "Eleutheria", which have bell disks from to a few millimeters in diameter, with short tentacles that extend out beyond this, which these jellyfish use to move across the surface of seaweed or the bottoms of rocky pools. Many of these tiny creeping jellyfish cannot be seen in the field without a hand lens or microscope; they can reproduce asexually by fission (splitting in half). Other very small jellyfish, which have bells about one millimeter, are
Jellyfish Lake the thickness of the sediment (at least 20 meters) and the rising sea level since the end of the last ice age. About 12,000 years ago, the sea level had risen to the point that sea water began to fill the Jellyfish Lake basin. Two species of scyphozoan jellyfish live in Jellyfish Lake, moon jellyfish ("Aurelia" sp.) and the golden jellyfish ("Mastigias" sp.). The golden jellyfish are most closely related to the spotted jellyfish ("Mastigias papua") that inhabit the nearby lagoons. They are similar to the spotted jellyfish in that they derive part of their nutrition from symbiotic algae (Zooxanthellae)