That's a wrap

Hello again from the Nathaniel B. Palmer. Today is the day we arrive into port and many of us are excited to come home and share our experiences, stories, and pictures with our loved ones.

As we are wrapping up on our journey,  I am excited to get back home to start working on my remaining dissertation projects with my study species, the pycnogonid Nymphon australe.

Pycnogonids are very interesting benthic invertebrates.  They are often referred to as sea spiders due to their similar appearance and body plan to land spiders. Sea spiders are not land spiders and are more closely related to horseshoe crabs. Sea spiders have a minute central body often surrounded by four pairs of walking legs. However, some spiders can have up to six pairs of walking legs. Since legs make up most of their body, they actually breathe through and carry their internal organs in their legs. Interestingly, sea spiders are found in every ocean, however in sea spiders in the Southern Ocean are a wonderful example of a phenomenon called “polar gigantism”, where they grow to be notably larger than their counterparts found in other oceans.

Another very interesting fact about sea spiders is that most species exhibit paternal care, similar to sea horses and some penguins. The maternal parent will lay the eggs and pass them to the paternal parent, who will then fertilize the eggs and carry them on a special pair of appendages called ovigers. The male will carry the eggs until they hatch, and the larvae will stay with the dad until they are developed enough to leave. We have seen male sea spiders carrying up to six egg clutches at a time. For the first time this cruise I saw a male carrying egg clutches that were different colors and I often observed some egg clutches that were in different developmental stages on the same male! This is exciting to me because one of my dissertation projects is looking at the genetics of these egg clutches to determine if male sea spiders are mating with the same female spider or with multiple females.

One of my favorite sites we sampled this cruise was a site where sea spiders were the most abundant taxa we sampled. Everywhere I looked I could see sea spiders in the trawl. Prior to sampling, we could see on our yo-yo camera footage that there would be a plethora of sea spiders at this site, however nothing compared to being there in person and being a part of sampling. I’ll never forget Ken, our senior scientist telling me it was time to step away from the trawl to go inside and jokingly stating he would have to have me held back from going to get more sea spiders.

It is bittersweet that our time here is ending. While I will miss the friends I’ve made and life on the boat, I am excited to go home and back to my life in Michigan.  Lastly, I want to give my best friend Kellee Peters  a shoutout and wish her a very happy birthday today!!  
 
Jessica Zehnpfennig
PhD Candidate
Central Michigan University.