Standard Views and Imaging Protocols

            The imaging of terminals is done according to the protocols of the Manual for Standard Views. The manual itself, as well as the ontology of anatomical terms is produced dynamically from the databases that controls the image collection.

Morphology

            Each of the more than 500 spider species plus close relatives (the arachnid orders Amblypygi, Schizomida and Uropygi) included in the Tree of Life: Phylogeny of Spiders project will be documented in hundreds of images. The primary tool for these morphological atlases will be scanning electron microscopy (SEM). Using SEM, we can examine structures at a much higher resolution than is possible with light microscopy. SEM is especially suited to examining spinneret spigots and other fine details of morphology. SEM imaging has played an increasingly critical part in the discovery of new characters for phylogenetic analysis. Additional imaging will be done using light microscopy with a series of images taken at different focal planes combined using the software package Auto-Montage. Each taxon is assigned to a clademaster, who is responsible for obtaining specimens for both morphological and molecular analysis, and for completing the series of images.

            Another important source of information is legacy data. As of 2003, there were 68 cladistic analyses of spiders including morphological data for three or more genera. Most of these were published or in press, although some were in an advanced state of progress but not yet submitted for publication. Taken together, these 68 matrices include members of 885 genera scored for over 4000 characters. Many of these characters are similar to or duplicates of characters in other analyses, so a major challenge was to synonymize characters across matrices. This matrix of legacy data will be the starting point for the Tree of Life spider matrix. Some legacy characters accepted as is for the Tree of Life project, others will be modified to better suit the taxon sample, still others will be excluded as not useful to address the deep scale questions addressed by the Tree of Life project. New characters will also be added based on the results of the SEM imaging and other observations.

Scanning electron micrograph showing spinnerets of female Latrodectus hesperus (Theridiidae). One species can have up to seven different types of silk. Note the variation in the form of the various spigots, indicating different types of silk. Most spiders have three pairs of spinnerets, the anterior lateral spinnerets (ALS), posterior lateral spinnerets (PLS) and posterior median spinnerets (PMS). Note also the colulus (CL) and the anal tubercle (AT).



Scanning electron micrograph showing the tarsal comb and claws of female Latrodectus hesperus (Theridiidae). The modified ventral setae on the ventral part of the fourth tarsus are used to comb silk out of the spinnerets silk in wrap-attack behavior.

Scanning electron micrograph showing setae on leg of Uloborus diversus (Uloboridae). Note the diversity of forms found in seta morphology.

Composite image created using Auto-Montage showing the face of Deinopis spinosa (Deinopidae).