Is lobster blood blue?

An interesting side-product of some of my experiments have been the varying colours of the lobster haemolymph. I remember once watching QI and there was a question about lobster (or was it crab?) blood - and the 'correct' answer was that it was blue. But is this correct? I remember shouting at the TV at the time that it was wrong (I was a misunderstood lobsterologist, after all...)

When I was doing my PhD, I uploaded a photo to twitter which people went a little crazy for. It was from the experiments I talked about in my previous blogpost and it even surprised me. Each blood sample was a different colour! All the lobsters were from a similar location (Ilfracombe, Devon), similar size (92 - 100cm in carapace length) and mostly female.  So, why, then, is there such a discrepancy... and most important of all... why aren't any blue?!!

Lobster blood samples for protein and metabolite quantification - the white bits are haemocyte pellets. Photo taken by Charlotte Eve Davies. 

First of all, let's get something straight. Lobsters don't have blood. I know I say it above and I will say it again, but as previously explained, lobsters don't really have blood. In fact, lobsters don't even have a 'closed' circulatory system like us (or mammals). Although they have a heart, which beats, and arteries, through which haemolymph (lobster 'blood') is passed through to bathe the organs, there are no veins to pass the haemolymph back to the heart. Instead, it returns to the heart via interconnecting spaces known as venous sinuses. For this reason, you will sometimes hear that the lobster's circulatory system known as an "open" circulatory system.

Okay, now that's out of the way, back to blue blood business. Some of us may have seen the (in)famous video or photos of bottles of horseshoe crab blood being decanted in a factory, for use in medical research... and we are wondering why my photo above doesn't show a similar brilliant blue hue? This is because, firstly, my samples were taken directly from a syringe, into a tube, which was closed, centrifuged and put in the freezer almost right away to stop the blood from clotting (the little white pellets you see are blood cells, or haemocytes, from the centrifugation). So the samples weren't exposed to much 'air' or namely, oxygen. 

As mentioned in one of my previous blogs, haemocyanins are the crustacean version of our haemoglobin; they are proteins that bind and transport oxygen throughout the body. Haemocyanins contain two copper atoms that bind a single oxygen molecule (remember it's O2... not O1) rather than Iron, which is what binds to oxygen in human and most mammalian bodies. Now, it's oxygenation that causes a colour change between the colourless Cu(I) deoxygenated form and the blue Cu(II) oxygenated form which is why in some cases, a nice blue colour can occur, especially when exposed to the open air - air contains oxygen which reacts with the copper present in the blood, giving us the blue colour.

However, this is not always the case. Protein levels in the blood, or haemolymph, of lobsters, and all crustaceans, are constantly changing. This can depend on the stage in the moult cycle (i.e. is it about to shed it's shell to grow?), the reproductive status (whether it is about to try and find a mate, or lay eggs) or even whether a lobster is diseased or not. It was interesting that in my photo, one sample was very dark green (bottom row, 4th from the right) - we think that this may have been due to reabsorption of eggs. There is a protein, vitellogenin which is synthesized by the ovarian tissues in lobsters. During female maturation, extra-ovarian vitellogenin is transported through the hemolymph to the ovary and is taken up into the cytoplasm oocytes, or eggs. Egg reabsorption can happen for a umber of reasons, be it adverse conditions (if the lobster is stressed), or if the egg were released too early and the lobster then needs to moult. 

More recerntly, during my first postdoc, I have been working on a virus in the Caribbean spiny lobster Panulirus argus. The virus, Panulirus argus Virus 1 (PaV1) has some interesting effects on the haemolymph of infected hosts. It turns it a very white, milky colour, rather than the usual amber colour, due to the degradation of hemocytes (blood cells). This is how we diagnose clinically infected individuals, pulling the tail away from the body a little and looking at the almost clear membrane covering the abdomen, it can clearly be seen whether or not an animal is infected.

Diseased vs. Healthy Comparison: The lobster on the left in this shot is healthy while the one on the right is in the last stages of PaV1. During this time the hemolymph turns from clear/amber to white, as you can see in the middle syringes. Photo from http://www.pav1.org/

So that's how we know... lobster blood isn't always blue.

Mojito.... I mean... Puerto Rico!

I seem to have gone on a rampage about lobster blood over my last few posts. I will relieve you of the science with a tale of some exciting sunny marine biology!

As some of you know, as well as my research, I work at Swansea University as a part-time teaching assistant, and last year the university started it’s new Tropical Ecology Field Course, in Puerto Rico. Now, as most of you will not know, over the past year I have been in talks with a university in Mexico about applying (and indeed applying for) a postdoc. I found out in October that I got the funding for the project and I have been planning my departure from Swansea. However, I decided to go out with a bang and volunteered as a member of staff for the field course in Puerto Rico (hard life, I know). My Caribbean Sea-life knowledge wasn’t really up to scratch so I thought this would be an excellent chance to get to grips with what will probably be the next two years of my life. The trip was lead by Dr. Richard Unsworth (seagrass lover extraordinaire) and Nicole Esteban (sea turtle expert) in addition to Dr. Ed Pope (of PhD viva fame), Dr. Ian Horsfall (sea cucumber hugger) and Dr. Penny Neyland (plant fondler…. hang on, what’s she doing there?! Tehe)

So, in the early hours of a cold January morning we set off from Swansea, armed with foldable quadrats, dissection trays and bikinis (all the essentials... ya know). After a 4-hour coach to Heathrow, a flight to Houston Texas (where we may or may not have left the bags on the luggage carousel and Ed may or may not have tried to exit the airport without the students).. another flight to San Juan, and another 3-hour coach we arrived in the little town of La Parguera and our home for the two weeks; Isla Magueyes Field Station. Which by the way, was just a field station, on an island. I was picturing a larger island, with roads and stuff (as were some of the officers at the American immigration apparently, when they tried to get some students to write a street address.. another story!)… it was paradise.

There were a few iguanas.

Luckily, Rich and Nicole had been there for a few days already getting everything ready for our grand arrival (oh yeah, did I mention we were bringing 22 students as well?). We had a briefing in the classroom followed by an introductory snorkel. Although at the time not everybody was up for it, this was probably the best idea - we had been travelling all night and most of us were zombies but if left to our own devices we would have just slept and jet-lag would have ruled!

The first ‘official’ day was snorkelling practise from the various wharfs and docks around the island, with a fish measurement and biomass estimation activity, whereby we set out a line of wooden fish (lovingly transported by students last year) which we knew the size of, and the students had up to 3 tries to improve their guesses. This is really important for things like AGRRA surveys where you can use the length of a specific species to estimate it’s biomass using info freely available on FishBase. Other activities were fish ID (self explanatory), fish behaviour (trying to follow a fish for a few minutes is HARD), fish species and fish abundance, where students experienced the difficulty in estimating fish abundance underwater. 

Day three involved boat based snorkelling… now here let me introduce you to something essential that we all loved to hate. An SMB, or surface marker buoy... is, as the name suggests.. a buoy which marks the surface where a diver/snorkeller is underneath the water. In a tourist hotspot like Isla Magueyes and around, these were essential for safety.. but sometimes.. they got in the way. Now, not naming any names… but I’m pretty sure that we didn’t end the week with all the SMBs we started with (I’m looking at you, Jack.. Elizabeth…). Having an SMB entangle itself around your neck/snorkel/weight-belt, let me tell you, is not a nice experience... but neither is Richards face when you have to tell him you tried to tie one to a rock then lost it! Anyway, SMBs aside.. today we used the carefully re-assembled quadrats to look at percentage cover of corals, sponges, algae, seagrass (because nope, they are not the same thing) plus the invertebrates on the seabed.. in both the day and the night (spooky!!). This activity essentially taught me how bad my coral ID skills were but hey! I had another week to improve. And to play with the territorial damselfish... 

The next couple of days were based on teaching and learning AGRRA. AGRRA, or to use it’s full name; Atlantic and Gulf Rapid Reef Assessment is a technique used to assess coral reef benthos. This includes understanding how to assess coral reef health, and for our students, to assess coral reef health of reefs in Puerto Rico by examining how the biota of healthy reefs changes as they become degraded. There is also a technique for assessing coral reef fish assemblages, which applies the knowledge of reef fish we developed on day 1 to assess coral reef fish communities in Puerto Rico. Again, we used it to examine how the fish communities of healthy reefs change as they become degraded. Now obviously, our surveys were small, but when used for research projects, these techniques are widely comparable and are used by scientists in Universities, Government and NGO’s for assessing coral reef health in Caribbean and Pacific.

Early morning commute to the sampling sites. Life is hard.

Even though it was a marine ecology field course, a super important part of tropical marine ecosystems are mangroves. So, under the supervision of our resident plant lover Penny, we headed out to Laguna Monsio José to learn about these fascinating ecosystems.. because yes, although a mangrove tree is a plant, the forests mangroves form are among the most productive and biologically complex ecosystems on Earth. As described in this great NatGeo article.. “birds roost in the canopy, shellfish attach themselves to the roots, and snakes and crocodiles come to hunt. Mangroves provide nursery grounds for fish; a food source for monkeys, deer, tree-climbing crabs, and a nectar source for bats and honeybees”. As well as squelching through the mangrove mud, we snorkelled through the roots to check out diversity of fish that live there... maybe plants are pretty cool after all.

The students also learnt how to seine net.. and this was an interesting one. As marine biologists, they are lucky in the fact that they have already taken part in a field course in the UK (at the Field Centre in Orielton) so are familiar with netted species back home.. so here we did it at night and in the morning. Both of which I missed as I was asleep very busy science-ing. 

Now.. we also did a lionfish dissection. In the Caribbean, the lionfish (Pterois volitans) is invasive. That means, it's not supposed to be there. Native to the Indian Ocean, Southern and Western Pacific Ocean and the Red Sea, it is speculated that they were introduced to the Atlantic when released by "retired" aquarium enthusiasts. Luckily, cold water temperatures are keeping numbers at bay in the north, but this is not the case in the south where lionfish are spreading rapidly through the South Florida coast, the Gulf of Mexico and the Caribbean Sea. But so what? They are just fish right? Wrong. Lionfish are are voracious predators and non-selective feeders, with virtually no natural enemies due to their toxic spines. Studies have shown that a single lionfish can reduce juvenile fish populations by 79% in just 5 weeks. Wow.

We found some pretty cool stuff in our lion fish stomachs... including a mantis shrimp!!

Mantis shrimp! Fresh from a lionfish tummy

My favourite day by far had to be the seagrass sampling.  SeagrassWatch is the internationally recognised method for assessing seagrass meadows. It allows scientists to examine the differences between healthy and degraded seagrass meadows and our students were able to help establish a long-term seagrass monitoring site in Puerto Rico! If you are a marine scientist that is interested in taking part.. check out the manual here. 

Seagrass are important; like mangroves, they support whole ecosystems. The habitat complexity within seagrass meadows enhances the diversity and abundance of animals. Seagrasses on reef flats and near estuaries are also nutrient sinks, buffering or filtering nutrient and chemical inputs to the marine environment.... They also stabilise coastal sediments. Most important of all, they are a nursery for all sorts of reef critters... including my buddy, the spiny lobster. Below is a video of me doing what I do best, harassing a couple.

The last few days were reserved for the students to undertake their very own 'mini research projects'. These 5 projects ranged from tarpon behaviour... to abiotic driver of benthic composition, the latter of which I was lucky enough to take part in! 

A-team. 

Overall, a great week was had by all. I can say that although I went as a member of staff, I was constantly learning and I feel safe in the knowledge that I now know my squirrelfish from my angelfish. A must, if you plan on undertaking a postdoc in the Caribbean... (but more of that in my next post!)

The life and times of lobster girl...

Okay so I know I've been threatening to start up a blog for quite a while, but this time I really mean it! What is this change of heart in aid of, I hear you ask? Well, I only went and got a travel scholarship didn't I... Clever girl. But first, for those who don't know me... let me introduce myself.

To my friends back home it may seem that I have been partying in Swansea for the last *ahem*.. 6 years, but in amongst all that dancing, beach BBQ-ing and surfing, I managed to obtain a Biology degree (hurrah!) and am now well on my way to getting a PhD and becoming a doctor (Oooh!).

Sampling on a commercial fishing vessel near Devon.

On the other side of things, there are my friends in Swansea, who simply know me as 'Lobster girl.. that girl that does lobster stuff... the one with the lobster tattoo!' No, I am not some sort of magical superhero with giant claws for weapons, but a lobster pathologist looking into all things fatal and disastrous to our beloved European lobster (Homarus gammarus, for you science geeks out there). I am passionate about disease susceptibility, with special reference to impacts of invasive species (yes, I'm talking about you, you pesky Americans). I am also a huge supporter of sustainable fisheries, rather than banning fishing altogether (sorry Hugh)... and am interested in the implementation of MPA's, especially how disease susceptibility might change within conservation areas.

How did I get into this line of work? Well, it's all down to my lovely supervisor, Prof. Andrew Rowley (who never updates his website, it seems), who offered me a lobster project for my dissertation as I neared the end of my bachelors degree, simply for being in his office at the right time, looking at a 'new' parasite that fishermen had been finding on lobsters around a Marine Conservation Zone (MCZ). Naturally, the two modules I had decided against taking that year were Parasitology and Cell and Immunobiology, so as you can see, it started off well. Not.

Lobster research in the UK is limited, the real hub of activity is based at IMR, Norway, whereas American lobster research is a vast area, spanning all over the US and Canada. As I started my PhD my first 'project' was a collaboration with the New England Aquarium in Boston, Massachusetts, where they are nearly as lobster mad as me. It was a match made in heaven.

Some of my baby research subjects. 

At the moment I am back to looking at parasites (should have taken that module...), which is really interesting, and I will keep you updated, but I am also starting up a new collaboration with the AVC Lobster Science Centre, in Canada, this coming fall.

I have been lucky enough to get two travel scholarships, one from the Society of Biology  and one from Climate Change Consortium for Wales (C3W),  and so I commence my travels in September. On top of the trip to Canada I am heading down to NEAQ to tie up some loose ends, and having a cheeky couple of nights in NYC before heading to Virginia to visit my amazing friends Tessa and Rebecca, who interned this summer at our department in Swansea.

I do hope to keep everyone updated with my antics (and frantic preparation, packing and tie-ing up of loose ends here at Swansea), but guaranteed I will forget and you will be reading my next blog at some point in 2015.

In the meantime, you can tweet me @_CharlotteEve_, or check me out on LinkedIn.