Project Overview:
This project aims to create visually convincing images of copepods to demonstrate individual behaviors in a research or educational setting.
Authors:
- Celeste Fowler, Scripps Institution of Oceanography
- Dr. Jeannette Yen, School of Biology, Georgia Institute of Technology
- Dr. Jules Jaffe Scripps Institution of Oceanography
Very Basic Copepod Introduction:
(Skip this if you already know what a copepod is.)
Copepods are a type of crustacean, the class of animals that also includes shrimps, lobsters, and crabs. Copepods are one of the most abundant animals on the planet. Most are saltwater plankton, living their entire lives in the open ocean without ever touching the bottom or surface. Copepods also live on the sea bottom, in fresh water, as parasites on fish, in caves…
Euchaeta Biological Introduction:
Copepods in the genus Euchaeta are planktonic and predatory. Congeners of Euchaeta (Kingdom Animalia, Phylum Crustacea, Class Copepoda, Order Calanoida, Superfamily Clausocalanoidea, Family Euchaetidae, Genus Euchaeta) live in seas from the Antarctic to the tropics, within the fjords of Norway and Puget Sound, and in deep lochs of Scotland. In their respective open-ocean planktonic communities, these copepods are often biomass dominants because of their high abundance, large size, and high lipid content (up to 70% their body weight). The image to the right was taken by Yen and Strickler and shows a typical Euchaeta. The long antennules are lined with sensitive setal receptors to detect fluid motion and odors. This photo of the live subarctic species, shows its natural coloration with blue oocytes within the oviducts and iridescence imparted by the thin caudal setae. The robust capture appendages, the paired maxillipeds, are shown extended away from anterior section of body.
Computer Visualization Introduction:
We created and animated our model using 3D Studio Max from Discrete Logic. This high-end animation package is widely used by movie special effects artists.
To create our models and animations, we first looked at illustrations in the literature. Rose 1933 gave us a good starting point. To create the prosome, we scanned 2D images from Rose into the computer and traced them using Bezier curves to create the outline of the prosome as seen from the left-hand side. We then made an estimate of curves representing the outline of the prosome as seen from the rear. Using these two sets of curves, we were able to create a Bezier patch surface approximating the prosome. We then checked our results by rendering images from several viewpoints and comparing them against preserved specimens. We also showed the images to Annie Townsend, curator of the SIO Planktonic Invertebrates Collection. She was able to suggest many important improvements.
The other segments of the prosome and urosome were constructed in a similar fashion, as were the appendages. We found that NURBS surfaces generally gave better results with less effort than other techniques for modelling curved surfaces.
Setae provided a special animation challenge, as there are so many of them. After exploring several techniques we used loft surfaces created from circles and Bezier splines. The tip of each seta was attached to a controller, so that each seta could be individually positioned if necessary. We generally avoided this by attaching the tips of each set of setae to a master controller. To give a more natural appearance, the setae on the maxillae are translated and rotated using a random noise function.
To animate our model, we first determined the range of motion of the joints by examining preserved specimens. We then looked at video of live animals. Using key frame animation, we were able to approximate the motion of the living animals. Once the computer model had been animated, it could be examined from any angle and at any speed.
Jump to animations
Abstract submitted to ALSO 2000
Fowler, C., Marine Physical Lab, Scripps Institution of Oceanography Yen, J., School of Biology, Georgia Institute of Technology Jaffe, J., Marine Physical Lab, Scripps Institution of Oceanography 3D VISUALIZATION OF A CALANOID COPEPOD, EUCHAETA To afford a better understanding of predatory copepod appearance and behavior, a three-dimensional computer model was created of a Euchaeta. Using the model, anatomy and behavior may be illustrated and examined from arbitrary viewpoints. Such a model can be used in many ways, for example: to communicate the features of the animal to the lay public; to understand the spatial/temporal relationships of predator/prey interactions through the examination of behaviors from selected viewpoints; and to increase our understanding of aquatic animal behavior through examination from viewpoints difficult or impossible to achieve using previous techniques. The model represents a synthesis of current knowledge from traditional sources: textual descriptions, drawings, photographs, and examination of preserved specimens, as well as from high-speed two-dimensional videography of living copepods and from discussions with experts. Although creating the model required a substantial time commitment, we believe the model shows great promise as a tool to illustrate aspects of plankton morphology and mechanics that few have had the opportunity to observe. SS23 SS15 CS37 ORAL FOWLER, C.