I believe that the best way to convey the maximum morphological information of a sturgeon habitus is to have a descriptive text accompanied by a detailed scientific illustration. Text and illustrations can compliment each other and never can one serve its full purpose without the other. Although illustrations may have a purely diagnostic purpose, such as species identification, they can achieve much more than that bare minimum. A super‐detailed illustration may satisfy all sturgeon experts since it treats meristics, morphology and a host of anatomical peculiarities. Selective emphasis in detail, along with proper captioning can further help guide the reader to important or key features relevant to sturgeon morphology. Photographs can be useful if color happens to be a major diagnostic feature (e.g. certain reef fishes), but the cost of such reproductions has always been a problem. Fish photographs taken of specimens out of the water, suffer from several shortcomings: 1) Intense glare due to the wet nature of the subject is often amplified by the thick mucus layer on the skin surface. 2) Overall tonal similarity, reflexion and clustering of detail are factors that make it difficult and sometimes impossible to carry out proper fin ray, scute or scale counts. Illustrations, however, can emphasize certain details (characters) which are not clearly visible or easily overlooked on a photograph. Such features may escape notice by the viewer even when looking at the actual specimen. Expert morphologists can potentially become the best scientific illustrators but for those less learned in this field, it is suggested to first consult biologists who specialize in the species prior to planning any illustration of a species. The expert advice will be helpful in pointing out what characters are typical versus those that are more unusual. There are several procedures which can be used to varying degrees to improve the appearance of the original in graphic form. These depend on factors such as whether the fish is preserved or cannot be sacrificed in the name of science. For example, in order to capture properly the shape and contours of small and relatively flat fish (e.g. species of the family Centrarchidae), the specimen can be placed on a photocopier and the size of the photocopy can be adjusted to the size the drawing is to be made. The photocopy is ready in an instant and is more accurate than countless hours of caliper measurements. In fact, the photocopy gives a more accurate rendering than the human eye can estimate since our vision suffers from the stereoscopic‐single viewing source while a photocopier scans the image from one end to the other. Thus, a photocopy‐produced image is so true to life, that it would take human vision to have dozens of eye‐balls, lined along the entire length of the fish, all focused only at what is directly below their position above the specimen. The photocopy is then traced onto a transparent paper but in order not to have a reversed image, the other side must than receive a pencil outline as well. It can then be laid down on a hard board and by scratching the surface of the tracing paper, one can press down a faint pencil deposit onto the board. The above technique is not well suited for sturgeon since they are usually too big or too precious to be sacrificed. Sturgeons are also too tubular in shape and a photocopy can only provide a good image of the area directly in contact with the glass. In this presentation we deal with the actual procedural techniques of doing sturgeon illustrations but first, a warning about museum specimens. Often, museums are limited by the size of the sturgeon that can be properly preserved wet (e.g. alcohol/ formalin). Dry mounts are usually deformed and certain aspects of the fish that are apparent when alive are lost. For example, on Acipenser sturio, it is common for the adults to have an adipose layer covering the plates on the fins. This involves tracing every bit of detail and is best done with a pencil. Within many hours or days, every millimeter of detail is transferred from the photo to the paper. Specimens preserved in alcohol also exhibit degradation of the outer dermal layer and a complete loss of the mucus layering. This in turn, causes the re‐appearance of scutes which were already in the process of absorption. Also, there is a reversal in overall contrast with all ossifications (normally same color or lighter than surrounding skin), in time, becoming darker than the surrounding skin. These wet preserved specimens lose the tonal color range of a live specimen. For example, the very dark back and laterodorsal surface in contrast to pale lateral scutes (as in A. gueldenstaedtii) is lost. A perfect example of these problems can be seen in the illustrations by Brant 1886. In light of these problems, it was soon realized that photography was the only way to proceed in order to combine realism and the effect of depth perception, both critical factors in sturgeon illustrations. The aquaculture community was very helpful in providing live specimens as were the enormous sturgeon hatcheries of Russia. These fish are critical brood stock specimens and usually could not be sacrificed for transportation to the laboratory for illustration purposes. This is why photography became a critical recording method. In order for the parallax distortion to be kept to a minimum, a lens of at least 100mm. focal length is considered essential. This way, the width of the viewing angle is kept at a minimum. If one were to take dozens of mophometric measurements on a large fish such as a sturgeon, a strange thing would happen when actually taking those numbers and translate them into an illustration. Because all body parts are treated equally, those further from the observers' eye (such as dorsal scutes as opposed to lateral scutes) will be enlarged. Thus, biometric measurements via caliper will always give a 2 dimensional rendering of a specimen, flattening out the reality of depth. Photo tracing of slides produced from long focal length photography is the only possible way to achieve the 3 dimensional effect. Morphometries, by the very nature of how they are taken, does not address shape and depth (perspective) simultaneously. We will now look at the procedure of photo tracing in more detail:

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   |texte=   Illustrating Sturgeon Species: the art of science in highlighting morphological features
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