Comb jellies living in the central Baltic Sea are a bunch of babies. In this part of the world, members of the species Mertensia ovum don’t appear to reach adulthood but instead sustain the population by reproducing while still larvae, reports a new study published online April 25 in Biology Letters.
It’s well known that many comb jellies — gelatinous marine animals that live at various depths of the ocean and use sticky tentacles to capture their meals — can become parents before reaching adulthood. This new work is “actual proof from nature that there is an entire population maintained by larval reproduction,” says study coauthor Cornelia Jaspers, a graduate student at the Centre for Ocean Life at the Technical University of Denmark in Charlottenlund.
Jaspers and her colleagues suspect that pressure from predators might be driving this comb jelly to start producing a few eggs early in life.