The exhibit is 14 large format prints of photographs on aluminum plate, each accompanied by a poem inspired by the image. The photos were taken by Adam Summers and processed by Ilya Brook. The Poems were written by Sierra Nelson.
The fishes depicted here have been specially treated to make the stained skeletal tissues visible through the skin and flesh. The technique uses two vital dyes – Alcian Blue to stain cartilaginous elements a deep blue and Alizarin Red S to turn mineralized tissue crimson. The specimen is then lightly bleached with hydrogen peroxide to remove dark pigments, leaving a snow-white fish. Flesh is dissolved with Trypsin, a digestive enzyme found in your intestine. Trypsin attacks most proteins but does not harm collagen, the principle fibrous material that holds the skeleton and skin together. In order to make the skin and remaining connective tissue invisible the entire specimen is immersed in glycerin. The index of refraction of collagen is very similar to that of glycerin, so the flesh seems to disappear. If you return the specimen to water the collagen will turn white again and the skeleton will be hidden. This technique is only effective on specimens that are less than about 1cm in thickness, and takes much longer for thick specimens than thin. A small fish might take 3 days to process while a larger animal could take several months.
Images are made while the fish is in glycerin on a light table with flash fill lighting. The total length of most specimens is around 25mm, though the largest is 170mm across, so a macro lens on a Canon digital SLR is used to capture the image. The photograph is printed in archival inks on an aluminum plate in a limited edition of five.
Frequently Asked Questions
Q. Where do you get the fishes?
A. These particular specimens were all collected either as by-catch from fishery operations, incidental mortality during scientific collection, or as part of a study on the developmental trajectory of the fish skeleton.
Q. How exactly do you stain them?
A. The protocol for staining these fishes works well on most small vertebrate specimens and has been in use at least 40 years. The details of the method used in the Biomechanics Lab at Friday Harbor Laboratories can be found in this Google Doc.
Q. How do you choose the fishes to stain?
A. In the course of research on skeletal shape a great variety of fishes are examined. If there are sufficient small examples of a particular species it is cleared and stained in order to more closely examine the relationship between bone and cartilage. Every museum of note has a substantial collection of vertebrates treated in this way and the collection in the FHL Biomechanics lab numbers in the hundreds of species. These specimens represent a subset that were judged to be visually appealing in addition to being data rich.
Q. Why did you do this to these fishes?
A. The Friday Harbor Biomechanics lab uses simple engineering and physics to understand how animals work. Often the first step in these investigations is understanding the underlying structure of the animal. For vertebrates this means visualizing the skeleton and the associated soft tissues. This investigation includes dissection and drawing, computed tomography (CT) scans, magnetic resonant imaging (MRI), laser scanning and clearing and staining. All of these fishes were prepared as primary or comparative material for studies of biomechanics.
Q. Why did you pair the images with poems?
A. For several years Friday Harbor Labs has been a place where the intersection of arts and science can be explored. This collaboration came out of an extended conversation on the similarity of mind set and technique between poets and fish biologists. This convergence led to an experiment on the communication of science in a poetic context.
Q. How did you make the images?
A. The specimens are in glycerine and are shot fully submerged in fluid. A large reservoir of glycerine is placed on a color corrected LED light table and the fish is posed. My scientific poses tend to be more rectilinear than the artistic ones that we hit upon in the course of this project. I use a Canon 5D Mark III with a 100mm Macro lens or the MP-E 65 1x-5x macro with a ring light fill flash. Often I hold the fill flash off to the side at an angle. I always have the camera on a tripod and use a remote shutter release. A difficulty with shooting through glycerine is that it naturally absorbs water. This means that the surface layer is often a slightly different density than the underlying fluid. That leads to Schlieren lines that blur the fine skeletal elements. I have not hit on any solution to this problem other than time. I pose the fish then leave the entire set up for several hours. Then I return and shoot without disturbing the fluid.
Q. How can I get more information?
A. Well, you could tweet to Adam Summers at @fishguy_FHL and Sierra Nelson at @songsforsquid. Or, you could email Adam at firstname.lastname@example.org.