Matching Deep Sea Larvae to their Adults is Harder than You May Think

Recently this past week while I was creating a reference library for shrimp species in the New England area I came across this paper: "A Mysterious World Revealed: Larval-Adult Matching of Deep-Sea Shrimps from the Gulf of Mexico"

The authors, Dr. Heather Bracken Grissom and Dr. Carlos Varela explain how often times scientists have a habit of incorrectly identifying deep sea species and their larvae as two separate organisms. The example they give in the paper is the giant deep sea shrimp, Cerataspis monstrosus Gray. The University of Hawaii has a great video displaying the adult form of this shrimp set to some pretty snazzy jazz music.

Now after watching that video, what would you expect the early stages of this animal to look like? Were you expecting this?

It's not hard to see how scientists were confused too. To add an extra layer of befuddlement, adult Cerataspis monstrosus live in the abyssal regions of the ocean (around 5,000m) whereas its larvae thrive mostly in the mesopelagic (around 500m).

It turns out this is not uncommon with deep sea organisms. Lots of variability has been observed not only between an organism's larvae and adult stages but their male and female counterparts too. The most famous example of this is when scientists identified three deep sea fish, Whalefish, Bignoses, and Tapetails, only to find out years later that they are all the same fish!

So how do we solve this persistent problem? The answer is by using genetics, bioinformatics, and a lot of statistical inference to match different species to their larval forms. This is by no means a simple procedure, as I am beginning to discover in my own research, but it is exciting!