I am so proud to have graduated my first PhD student, Dr. Chris Moore! 
Below is a collage of images from the past 6 years of Chris working in the Blakeslee lab:

Here is the introduction I gave about Chris before he delivered an excellent defense talk!

​My first experience with Chris was when I put out an ad for graduate students on a listserv back in 2015 shortly after I started at ECU, and he wrote to me with an enthusiastic email that immediately made him stand out among others that contact me. Chris had really looked into my research and spoke of how he might be able to move my research program forward. And that is truly what he did. Chris was one of my first students, along with Becca Barnard who is on Webex with us, and they both really got my lab going. The year that Chris was accepted, he started early and assisted on a side project, which ultimately led to a publication where he was a co-author. Chris has assisted on so many projects not only with my lab, but with others. He is incredibly generous with his time and is always enthusiastic about everything he does. He also works incredibly hard, and has pulled together some really fascinating research as he will talk about very soon. As a result of his research efforts, he is first or co-author on 5 publications already, with 3 additional publications in review and 1 in prep. One first-authored paper currently in review is in the journal Ecology, and it is past the desk rejection stage, which is very exciting! He has also applied for and received an incredible number of grants during his time at ECU. These include: Golden Key International Academic Honor Society, Society for Integrative & Comparative Biology, Sigma Xi, Garden Club of America, American Malacological Society, N.C. Coastal Conservation Association, N.C. Sea Grant / National Estuarine Research Reserve, N.C. Wildlife Federation, and the Lerner-Gray Fund for Marine Research. Altogether, this has totaled over 26,000, which is an incredible achievement for acquiring research funding to fund his work as a graduate student. Chris has also received multiple awards for talks, posters, and other competitions, including RCAW, Sigma Xi, SEERS conference, American Fisheries Society, CERF, AFS Tidewater. At ECU, he has had many leadership roles including in BGSA and AFS and has volunteered his time at many ECU events. He has also had an important teaching role in the department, at first TA’ing the Ecology lab and most recently as an instructor of BIOL 1050. Chris consistently receives high praise from students for his teaching and mentorship. Speaking of mentorship, he has mentored 9 undergraduate students in the department, including helping to mentor an honors thesis research project completed by Corey Winkler. He has also been incredibly generous of his time in terms of experimental design and statistical analysis for many students in my lab and in other labs. All these accomplishments demonstrate the high quality work that Chris has done over the years and what a truly good person he is. It’s hard to imagine my lab without him in it, but I know we will continue to collaborate into the future and stay friends.

And finally a bunch of pictures of the defense, his celebration party, and graduation!

This past spring we started a new project with Jim Morley's lab at ECU to examine black gill disease prevalence in the Pamlico Sound, where very little on the disease is thus far known in the region. We will use morphological and PCR-based approaches to try to get a better understanding of prevalence in these populations, since not all infected shrimp will be obviously symptomatic. We also intend to see if panopeid shrimp may serve as a reservoir of infection for panaeid shrimp in the region.

 We just got a paper published in Arthropod Systematics & Phylogeny that reassesses Eubrachyura systematics with the inclusion of several mitogenomes of panopeid species mud crabs. The paper can be found here: https://arthropod-systematics.arphahub.com/articles.php?id=70234

Systematic assessment of the Panopeidae and broader Eubrachyura (Decapoda: Brachyura) using mitochondrial genomics

Lucas A. Jennings, April M. H. Blakeslee, Krista A. McCoy, Donald C. Behringer, Jamie Bojko

Abstract
This study provides a broad phylogenetic analysis for the Eubrachyura, with the inclusion of three new Panopeidae mitochondrial genomes: Eurypanopeus depressus (flatback mud crab) (15,854bp), Panopeus herbstii (Atlantic mud crab) (15,812bp) and Rhithropanopeus harrisii (Harris, or ‘white-fingered’ mud crab) (15,892bp). These new mitogenomes were analyzed alongside all available brachyuran mitochondrial genomes (n = 113), comprising 80 genera from 29 families, to provide an updated phylogenetic analysis of the infra-order Brachyura (“true crabs”). Our analyses support the subsection Potamoida within the Eubrachyura as the sister group to Thoracotremata. The family Panopeidae aligns with the family Xanthidae to form the Xanthoidea branch, which is supported by current morphological and genetic taxonomy. A unique gene arrangement termed ‘XanGO’ was identified for the panopeids and varies relative to other members of the subsection Heterotremata (within the Eubrachyura) via a transposition of the trnV gene. This gene arrangement is novel and is shared between several Xanthoidea species, including Etisus anaglyptus (hairy spooner crab), Atergatis floridus (brown egg crab), and Atergatis integerrimus (red egg crab), suggesting that it is a conserved gene arrangement within the Xanthoidea superfamily. Our study further reveals a need for taxonomic revision of some brachyuran groups, particularly the Sesarmidae. The inclusion of panopeid mitogenomes into the greater brachyuran phylogeny increases our understanding of crab evolution and higher level Eubrachyuran systematics.

A warm welcome to Haley Hagemeier who joined the Blakeslee lab in August 2021 as a MS student. She has hit the ground running, helping us in the field in late August and presently doing an independent biogeography project on parasite diversity in invasive Asian shorecrabs (Hemigrapsus sanguineus) from sites ranging from Maine to North Carolina, which is part of a larger collaborative project. She is also developing her masters research project which will examine physiological tolerances to salinity of two native mud crabs that are infected by the "body-snatching" rhizocephalan parasite that we study in the lab: Loxothylacus panopaei. We want to determine if the crabs can survive low salinity waters that could provide a refuge from this castrating, impactful parasite. She will be also be investigating whether there is differential susceptibility to infection in the two crab species using lab experiments.

It was very exciting that two publications came out of my lab this summer! The first is a lab-wide projecting exploring the influence of salinity gradients on parasite prevalence in mud crabs of an invasive body-snatching parasite. The second is an international trans-Atlantic collaboration of two related Littorina snail species that show strong differences in their phylogeographies, partly due to opposing reproductive strategies. See the titles, authors, abstracts, and links below.

​(1) Invasion of the body snatchers: the role of parasite introduction in host distribution and response to salinity in invaded estuaries.

Blakeslee AMH, Pochtar DL, Fowler AE, Moore CS, Lee TS, Barnard RB, Swanson KL, Lukas LC, Ruocchio M, Torchin ME, Miller AW, Ruiz GM, Tepolt CK (2021) Proceedings of the Royal Society Series B Biology. 288: 20210703. 
https://royalsocietypublishing.org/doi/10.1098/rspb.2021.0703

Abstract: In dynamic systems, organisms are faced with variable selective forces that may impose trade-offs. In estuaries, salinity is a strong driver of organismal diversity, while parasites shape species distributions and demography. We tested for trade-offs between low-salinity stress and parasitism in an invasive castrating parasite and its mud crab host along salinity gradients of two North Carolina rivers. We performed field surveys every six to eight weeks over 3 years to determine factors influencing parasite prevalence, host abundance, and associated taxa diversity. We also looked for signatures of low-salinity stress in the host by examining its response (time-to-right and gene expression) to salinity. We found salinity and temperature significantly affected parasite prevalence, with low-salinity sites (less than 10 practical salinity units (PSU)) lacking infection, and populations in moderate salinities at warmer temperatures reaching prevalence as high as 60%. Host abundance was negatively associated with parasite prevalence. Host gene expression was plastic to acclimation salinity, but several osmoregulatory and immune-related genes demonstrated source-dependent salinity response. We identified a genetic marker that was strongly associated with salinity against a backdrop of no neutral genetic structure, suggesting possible selection on standing variation. Our study illuminates how selective trade-offs in naturally dynamic systems may shape host evolutionary ecology.


(2) Population structure and phylogeography of two North Atlantic Littorina species with contrasting larval development. 

Blakeslee AMH, Miller AW, Ruiz GM, Johannesson K, André C, Panova M (2021). Marine Biology. 168: 1-16. https://doi.org/10.1007/s00227-021-03918-8

Abstract: Phylogeography provides insights into how historical and contemporary processes influence the genetic structure and gene flow in marine organisms around the globe. In benthic marine invertebrates, a species’ reproductive strategy can strongly impact phylogeographic patterns and distribution, with some direct-developing (non-planktonic) dispersers demonstrating strong genetic structure but also broad geographic spread. While seemingly paradoxical, past work has shown ovoviviparous species, like Littorina saxatilis, can be more successful colonizers of remote locations than species with planktonic larvae, like L. littorea. Both Littorina species overlap in much of their North Atlantic ranges but have different colonization histories: L. saxatilis is native on both North Atlantic coasts and islands, and L. littorea is native to the eastern Atlantic but introduced to the west. Using an extensive mitochondrial dataset (1236 sequences; 85 sites), we examined how their opposing reproductive strategies correspond to their distributions and phylogeographies. Littorina saxatilis exhibited a heterogeneous genetic structure reflecting post-glacial recolonization from multiple refugial sites, while L. littorea had a homogeneous structure with a post-glacial history characterized by recolonization from one main refugial area in the northeast Atlantic. Further, haplotype diversity was significantly depressed in northwest Atlantic L. littorea populations, signifying a strong bottleneck characteristic of a human-mediated introduction. In contrast, haplotype diversity in L. saxatilis was similar between the two regions, demonstrating long-term history on both coasts. Thus, our study suggests contrasting life-history characteristics were a major structuring force in the phylogeographic patterns of these related species following large-scale disturbances (natural and anthropogenic) that compel contraction and redistribution over large areas.

Laura did an excellent job with her thesis defense, managing to collect her data during the pandemic and then pulling together a nice thesis and presentation. Very proud of her hard work over the past 2 years!!

We were very excited that our course was able to run again this summer. Amy and I had an absolutely fantastic group of students (see lots of pics below) and it was such a fun teaching experience! It was so nice to once again instruct about the wonders of parasites in a hands-on environment where the students could design their own short projects. So happy to have been a part of this wonderful group of students, along with the other amazing Shoals faculty and staff this summer!

With my fellow colleagues, Amy Fowler at GMU and Carrie Keogh at Emory, we were able to recruit two undergraduate interns this summer for our parasite ecology internship at Shoals Marine Lab. The students are Grace Loonam (GMU) and Amanda Wolf (Emory). They did an excellent job getting acclimated to the island and also the parasites! They worked together on a joint project looking at signatures of trematode infection in Littorina spp. snails and have independent projects on the influences of temperature on cercarial shedding (Grace) and grazing/infection (Amanda). Super interesting findings so far! Because of COVID, they weren't able to be on the island the whole summer, but they were able to spend 3 weeks in June, go back to their home institutions and continue work there, and then return to the island for 2 weeks in July.

Tim had to postpone his field experiment until this summer 2021. He has set up various plots that include or do not include seagrass (Zostera) and the invasive seaweed A. vermiculophyllum. He is also surveying four local sites in the Beaufort and Harkers Island area for associated macroinvertebrates with seagrass and the invasive seaweed.