Malacology 101: Snail Sex

CW: NSFW snail facts.

Those who know me well know that I adore snails. Malacology – the scientific study of gastropods such as slugs, snails, and mollusks – has become a serious area of interest for me over the past year or so. My fascination with malacology began when I attempted to create my own biosphere (a contained, self-maintaining habitat for aquatic plants, mosses, and microscopic critters); one of my aquatic plants came with a tiny bladder snail (Physella acuta - AKA pest snail, or freshwater pond snail). I became utterly enamored with the tiny, adorable bladder snails until they bred so fast that I couldn’t keep up with them…they ended up eating literally all my water plants, so I needed to get rid of them. It turns out that they’re a common problem for aquarium keepers (and had I done my research, I would have known that). I decided that once I have the appropriate space and time to maintain an aquarium, I’ll probably keep larger aquatic snail species (ones that won’t procreate like crazy).

My appreciation for snails was quelled until I got another opportunity to keep them – this time, with terrestrial snails. One night, I received a message from a friend of mine, stating that he found a garden snail in the dumpster of the restaurant he was working at. He sent me a picture of the snail, asking if I wanted to keep it. An hour later, I bought a terrarium, a food dish, and found a pot for it to hide in, as well as some substrate, plants, and a stick for it to climb on – a pretty comfortable environment, when compared to a dumpster. I found out that it was a grove snail (Cepaea nemoralis), and I named it Biggie Snails.

Biggie Snails, about to investigate some carrots. 

Keeping garden snails is fun; they’re relatively low-maintenance and easy to care for, while being incredibly adorable and fascinating to learn about. However, like the bladder snails I mentioned above, most garden snails procreate very quickly. I wasn’t aware of this at first (again, I only did the bare minimum of research here) until I witnessed Biggie burrowing into the substrate, laying a full clutch of eggs.

Snails like to burrow down into the substrate (soil), to protect their eggs from predators. Here, Biggie chose to lay its eggs right beneath the food dish. 

Snails and slugs are hermaphrodic - they possess both male and female genitals. They prefer to mate and exchange their "genetic stuff" with others (which produces healthier stock), but if that isn't an option, some species can fertilize their own eggs. I’m unsure if grove snails prefer to mate with others or not; either Biggie had already mated with another prior to finding its way into a dumpster (sad), or it inseminated itself. At any rate, within a few weeks, I had at least 50 baby snails crawling around in the habitat I made for Biggie.

One of Biggie's babies, exploring the log in the tank. Notice how translucent it is; this one is only 5-7 days old.

A baby snail, exploring my thumb. Here, its shell is still somewhat see-through, but the brown stripes characteristic of grove snails are beginning to form. This one is about 2 weeks old.

The baby snails start out totally translucent; they need a lot of calcium in order to grow their shells properly (most terrestrial snail keepers use ReptoCal or a cuddlebone in their tanks; I’ve found that both work rather well). Unfortunately, only 15-20 of Biggie’s baby snails survived. Of those, I kept only one – Missy Shelliot – and I set the rest free into the wild. I have mixed feelings about setting them free; grove snails are an invasive species already (they came along on vegetable ships with European colonizers), and I don’t want to screw up the natural order. I set one snail free in different locations, with each location being 7-10 miles away from each other.

Missy Shelliot, who seems to enjoy exploring new places a lot more than Biggie does. 

I mentioned that snails need calcium for maintaining their shells; here's a good example of why. Missy Shelliot's shell is on the left, and Biggie Snails's shell is on the right. Biggie's slime isn't as strong as it used to be (he's getting rather old now), so he falls from the lid of the terrarium sometimes. This caused significant damage to its shell, exhibited by flaky white fragments in the middle of the spiral. Fortunately, though, the shell is beginning to grow back, due to the fact that Biggie is finally starting to notice the cuddlebone that I left in their terrarium.

Earlier this week, I caught both Missy Shelliot and Biggie Snails in the mating act. Slugs and snails display elaborate mating rituals that last for hours, which are specific to certain species. Supposedly, this keeps them from mating with other species and prevents them from making hybrid babies. Snail mating is equally fascinating as it is gross; they start off as if they’re about to argue, fight, or dance, but with their genitals out. Most snail species inseminate each other at the same time, both giving and receiving sperm. Some slug species also do this, but in slightly more entertaining ways – for example, great grey garden slugs can copulate in midair, suspended from strands of slime that can be up to 17 3/4 inches long. Banana slugs intertwine themselves in an S pattern, in which each one gives and receives sperm. However, un-twining themselves after mating is difficult, and could result in "apophallation" - one slug actually gnaws off the penis of the other (Gordon 1994: 31-32).

The two large snails are Missy and Biggie; the arrows are pointing to protruding dark spots, which are their penises at half-mast. The small snail towards the top is an innocent bystander, just trying to mind its own business.

Part of the pre-mating "dance", which is unique to only grove snails. The video is blurry, but since their dicks are out you probably get the point.

Of course I got a video of my snails’ pre-mating ritual – you know, for science – but I refrained from getting one of them in the act itself (I know they’re just invertebrates, but they still deserve to have at least a little goddamn privacy). As you can see in the photo and video, they both have taken out their penises and they began their “mating dance”, which actually lasted for three and a half hours. Their actual copulation took an additional three hours. For another version of the snail mating process, zefrank1 made a lighthearted video about it, which gets into the actual “spirited love darting” process. The gestation period for slugs and snails vary among each species. For grove snails, it’ll take approximately 3-4 weeks for a clutch of eggs to appear after mating. It usually takes an additional 4 weeks for those eggs to hatch, depending on environmental circumstances.

Useless (but hilarious) slug fact: slug genitals are disproportionally large, compared to the rest of their body. An example is that of the great grey garden slug - whose penis is half the length of its body. These traits are also reflected in their scientific names - for example, one banana slug species, dolichophallus, is Latin for "really long penis" (Gordon 1994: 31-32). Now you have a nice lunch-time conversation topic.

Though snail mating is fascinating, I could definitely live without seeing it in action ever again. Anyway, if you're interested in learning more about slugs and snails, I absolutely recommend these two books (Gordon 1994, 2010): 

Mental Health and Archaeology (Post-SHA Reflection)

TW / CW: in-depth descriptions of depression and mental health issues

I laughed way too hard at this. Sorry. 

This past week, myself and thousands of other archaeologists attended the 53^rd Annual Conference on Historical and Underwater Archaeology – i.e., the annual Society for Historical Archaeology (SHA) conference. It was a total blast – I got to explore Boston, I learned a lot of useful things during the symposia, I was able to meet professionals in my field and make connections, and I became inspired to put together a couple of topics for my own future presentations. I was surprised at the amount of familiar people who were at the conference; quite a few of my friends and colleagues, both known in person and on the Internet, attended. Meeting my Internet archaeology pals for the first time was incredible, though I didn’t get the chance to have many in-depth conversations with some of them (there also were a few people who I simply didn’t recognize until it was too late to introduce myself). The driving force in preventing me from meeting more people and networking, though, was the crippling depression I had during my trip.

From October to about mid-April, I get horrendous Seasonal Affective Disorder (SAD, which is…a convenient acronym). Symptoms are different for everyone, but for me, SAD causes mild to extreme depression, anxiety in social situations, sensory overload, and irritability. I recall feeling a sense of extreme sensory overload and anxiety during the opening reception of the conference, due to the sheer volume of people and voices who were gathered all at once in the Grand Ballroom of the Sheraton. Most nights after the symposia were over, I felt myself craving isolation and time alone, while simultaneously wanting to go out with my friends at the conference (which is typical for my SAD: equally wanting social interaction while desperately wanting to be alone, all at the same time, in one feeling). Depression affects my performance in the field and lab as well; I don’t think as clearly, I withdraw into myself, and I’m unenthusiastic (a trait that is very uncharacteristic for me). However, I’m not alone in this; after seeing fellow professionals talk about this on Twitter (see also Alex Fitzpatrick’s blog post on #DiggingWhileDepressed) and after talking in person to my colleagues, it is apparent that depression is a common problem within our discipline, especially within commercial and academic contexts.

Archaeologists who travel a lot for their jobs are away from their family, friends, and their entire home base for extended amounts of time. In the context of a conference, for example, one is surrounded by thousands of people within the same or adjacent disciplines, all of which are in different walks of life; though I feel very well-versed and experienced in my own field, I was surrounded by others who knew way more than I do about various aspects of my research interests. It can be hard to keep feelings such as imposter syndrome at bay (not to mention the SAD-induced social anxieties). It was difficult for me to navigate through my feelings during the SHA conference, a professional setting that was far from home, and is an experience that is still relatively new to me.

Aside from being apart from home often, cultural resource managers, academic archaeologists and graduate students are subject to immense workloads and unrealistic expectations. Archaeological fieldwork, lab work, and research are all physically and mentally taxing. Unfortunately, in the US, field technicians doing much of the “grunt work” in CRM don’t have access to health care through their company, which makes seeking professional help a difficult [read again: inaccessible] task. Graduate students who aren’t supported financially by their university experience the same issue. Academic archaeologists are expected to teach large classes, keep office hours, and publish their own research, while most have other obligations at home that need to be taken care of. Doug’s Archaeology highlighted some sessions and papers that explore some of the work that archaeologists have done to study and bring forward these issues. Discussions of mental health in our field are continuous and frequent, and I think that’s a very good thing; my hope with bringing this conversation back into the spotlight is that “mental health”, “emotional well-being”, and whatever else you want to call it, get the same treatment that physical illnesses do for archaeologists.

Since mental health varies so greatly among everyone, I’m refraining from handing out unsolicited advice – I don’t have any “advice” anyway. However, I do encourage folx to utilize their support groups – professional therapists, friends and family, colleagues, and so on – and, if you’re comfortable with speaking out about it, I encourage you to do so. I was surprised at the amount of solidarity there was out there when I started talking about it, and it inspired me to keep at it. However, I can’t stress enough how much clinical, professional therapy will help. As a side note, I never used to crack open about my own mental health, neither with whatever kind of other garbage I’m going through. There’s no specific reason for that; I just didn’t do it. However, I’ve been finding that being openly honest about it actually helps me cope with it; I’m no longer embarrassed to admit anything. I know how to treat and manage SAD, and at this point, I’m now able to recognize the different situations in which SAD resurfaces; though, I’m not afraid to admit that I’m still learning (mostly via the hardest ways possible) how to cope with the stress of working CRM, working in academic spaces, and being a graduate student all at the same time, all while being plagued with SAD. I thank my friends and colleagues for being part of my support system.

I think it’s crucial to remember that it is perfect normal and fine to become burnt out in a job and/or career that you genuinely enjoy. Needing to take a break does not mean that you stopped loving it, or that you no longer appreciate it. Being dedicated to the grind is one thing but treating yourself like a robot is another. Trust me, literally everyone in archaeology experiences this at some point in their careers. Please take the time that you need – get the help that you need – and take care of yourself this year.

Historical Ceramics and Electrolysis: An Experiment

A few weeks ago, I conducted an experiment using electrolytic cleaning to rid stubborn chunks of iron corrosion from ceramic fragments. These ceramic sherds were recovered by Tim Bennett and his family at the historic Warner Pioneer Homestead (20LV334), from Feature 19. Due to post-depositional processes (presumably from being in the ground for a hundred years with oxidizing soils and iron artifacts), these potsherds were encrusted with ferric (iron) concretions, which made it impossible to mend the sherds together with others from the same vessels (i.e. cross-mending). Cross-mending ceramic sherds is useful for determining the forms of vessels and their full decorations, which can be functionally and temporally diagnostic. The ferric concretions that were encrusted on these sherds were impossible to detach with typical artifact cleaning procedures.

For my purposes here, I’ll very briefly summarize the electrolysis process (I posted a lab manual for the process on my blog, located here). In short, electrolysis is the process by which ferrous artifacts are cleared of ferric corrosion via electrical current. Electrolysis is useful for determining an iron artifact’s past function. Since iron oxidizes, electrolysis also helps conserve artifacts by preventing further corrosion. The artifact (or in chemist’s terms, the cathode) is connected to a battery’s negative charge. To ensure an efficient electrical current, the iron artifact is Dremeled in the places where the negatively charged clips will be connected. The battery’s positive charge is connected to a steel rod or mesh, which is called the anode. The cathode and anode are placed in a bath with distilled water and baking soda (which acts as an electrolyte); the battery’s electrical charge essentially attracts the oxidation from the artifact to the anode, aided by the baking soda electrolytes. The end result is an iron artifact that no longer has ferric corrosion on its surface. In order for the electrolytic cleaning process to work, there needs to be a strong connection from the iron artifact’s intact/corrosion-free surface to the negative charge, to facilitate a strong electrical current.

At the beginning of this electrolysis experiment, I decided that I would test three hypotheses. The first hypothesis is that the battery’s electrical current would not be able to flow through the ceramic well enough. According to the American Ceramic Society, there are trace amounts of iron in all earthenware and stoneware clay bodies (I can’t seem to find a source that can tell me exactly how much is in each paste category, but there seems to be many variables that alter the amounts). Some ceramic glazes also contain amounts of iron, all of which vary depending on the glaze’s chemical composition and intended color. Being that the sherds were all plain whitewares and hard-paste porcelains with lead-based glazes, I feared that there wouldn’t be enough iron in the pastes and glazes to ensure a strong enough connection through which the current could flow. My second hypothesis was that the sherds would not be able to withstand the electrical current at all, and that they would fall apart soon after the voltage was increased. Only one of the sherds exhibited any kind of decoration (gilded bands running along the rim); I was concerned that any overglaze decoration would flake away during the process. Finally, my third hypothesis was that the electrolysis process would be successful, and that the electrolysis process could be used by historical archaeologists in the future to clear ceramics of ferric concretions.

Before I began the process, I gave each sherd an identification number. Giving them arbitrary numbers helped me monitor each sherd’s overall progress in the electrolysis bath more closely. I also kept track of which cathode clips were attached to which sherd, and I kept detailed notes during the whole experiment. Sherd #s 1-5 are all from lead-glazed whiteware vessels, and sherd # 6 was made from hard-paste porcelain. Sherd # 2 has two overglaze gilt bands that run along the rim, which unfortunately can’t be seen very well in the photo above (for descriptions of what these paste and glaze categories mean, the Maryland Archaeological Conservation Lab does a nicejob). Since our electrolysis bath at CMU is only equipped with four cathode wires, I put only four sherds in the bath at a time. As I stated previously, the iron artifacts that I clean electrolytically are always Dremeled first in spots where the cathode wires can be connected to the artifact’s original surface under the corrosion, which facilitates a strong electrical connection. Since the sherds were only covered with ferric concretions in small areas, the Dremeling step was not necessary. It did occur to me that a gentle Dremeling on the concretions themselves would efficiently get rid of them, but a grinding stone bit or a steel brush bit of a Dremel would certainly scratch the paste and glaze surfaces, thus furthering the damage on the sherds.

Since I really did not want my second hypothesis to occur, I altered the typical electrolysis process for cleaning iron artifacts to be slightly gentler on these ceramic fragments. As a general rule of thumb, the amount of voltage/amperage needed to clean iron artifacts in an efficient amount of time is calculated as one amperage per every two square centimeters of the artifact. Additionally, the higher the voltage/amperage, the faster the ferric corrosion repels from the artifact’s core. Since I didn’t want to zap these sherds into oblivion, I refused to follow my own guidelines. Instead, I kept the amperage low at first (5V/0.5A), and I increased the amperage gradually once I knew that it was safe to do so. Since I never leave the electrolysis running overnight (the process needs to be monitored closely), I needed to disconnect the battery wires and take the sherds out of the bath until I could tend to them again. After successfully cleaning iron artifacts, they need to be “stabilized” by letting them simmer in distilled water for 2-3 hours, and then baked in an oven at 200 degrees Fahrenheit for an additional 2-3 hours. After they’re baked and cooled down, they are covered with a microcrystalline wax to ensure that they don’t oxidize again. Since the ceramics are obviously not totally made out of iron, I skipped these last steps.

Fortunately, my first and second hypotheses didn’t work out, and my third hypothesis was deemed successful. Collectively, after about 18 hours in the electrolysis bath at 10V/2A, the ferric concretions could easily be wiped away from the glazed surfaces and hard-paste porcelain. The concretions on the whiteware clay bodies were slightly more stubborn, although I could still persuade them to come off by gently picking at them with a dental pick. The gilt decoration on sherd # 2, fortunately, did not disintegrate. Furthermore, unlike full iron artifacts, leaving the sherds out to dry overnight did not make the corrosion any worse. The ferric concretions flaked away during this process, but the ferrous staining remained. To remedy this, I soaked them in white vinegar for a few hours while periodically giving them a gentle scrub with a toothbrush; however, no changes were made.

Before electrolysis

After electrolysis

To conclude, these results suggest that electrolysis can be used to clean ferric concretions from historical ceramics. The process is especially useful for vessel fragments, since the absence of concretions make the cross-mending and reconstruction of full vessels possible. Furthermore, the electrolysis process did not damage the surface treatment or decoration on the sherds in the sample. Before using electrolysis as a standardized practice, however, more testing needs to be done on ceramic fragments with other forms of decoration to make sure that the electrolysis process does not harm other types of surface treatment. Additionally, the samples need to be monitored to make sure that the ferric staining does not grow worse (especially since the sherds were not “stabilized” afterwards).

For more background information about the Warner Pioneer Homestead, implore you to check out Tim’s blog. I am indebted to both Tim Bennett and Sarah Surface-Evans, who originally came up with the idea and let me take control of the experiment.