Everyone knows that a caterpillar will change into a butterfly and tadpole will become a frog, but did you know that marine sponges undergo metamorphosis too?
I am Rachel Collin, the director of the Bocas del Toro Research Station in Bocas del Toro, Panama, which is a part of the Smithsonian Tropical Research Institute. I study the reproduction and larval development of marine invertebrates (i.e. crabs, snails, or any marine organism without a backbone). This covers what sexes the animals are, how they mate or if they mate, how the eggs develop into juveniles, and how larvae develop into adults.
Adult marine sponges develop from larvae, similar to the way a caterpillar metamorphoses into a butterfly. Likewise, the adult sponge and its larva look nothing alike and they act differently. For example, sponge larvae actively swim around and adult sponges can't move.
By studying the genetics of these organisms, it can help us to understand how one genome can produce these two completely different kinds of life stages.
Specifically this project, sponsored by NMNH's Global Genome Initiative, will look at the differences in what genes are used in the larva versus the adult sponge. We hope to get a little closer to understanding how the same genes can be used to make these different life stages. We also hope to understand how the microbial community (or microbiome) changes across the life cycle and what impact that has on the sponge.
|Rachel Collin—At work in the lab. I always wanted to be a scientist and always had an interest in marine invertebrates, from my very first visit to the beach and intertidal when I was a child. I first got interested in invertebrate reproduction and development when I worked at the Friday Harbor Labs in Puget Sound for my Master's degree. I'm attracted to the diversity of different strategies animals use. It's amazing to me that some animals change sex; some inject sperm into the body cavities of their mates; some don't even need a mate to reproduce. And the larvae of different animals are so diverse and beautiful, it's hard not to want to know how they live.|
Understanding these sponges is much more than just an academic interest. Marine sponges are globally distributed and perform important ecological roles in all the ecosystems they are found. They also support diverse ecosystems both as a substrate as well as hosting a diverse microbiome. The sponge microbiome is more diverse that any other invertebrate; the amount of diversity is similar to the of microbiomes associate in our guts.
Few studies have explored the functional roles of microbial symbionts in distinct life-history stages. I hope our current GGI project will help us fill in this critical gap.
By Rachel Collin, Director of the Bocas del Toro Research Station, Smithsonian Tropical Research Institute, Panama (edited by GGI Staff).