J C Otto

Bio: J C Otto is an academic researcher. The author has contributed to research in topics: Maratus & Maratus volans. The author has an hindex of 1, co-authored 1 publications receiving 8 citations.

Description of a new peacock spider from Cape Le Grand, Western Australia, with observations on display by males and females and comparative notes on the related Maratus volans (Araneae: Salticidae: Euophryinae: Maratus)

Abstract: Description of a new peacock spider from Cape Le Grand, Western Australia, with observations on display by males and females and comparative notes on the related Maratus volans (Araneae: Salticidae: Euophryinae: Maratus) Jürgen C. Otto 1 and David E. Hill 2 1 19 Grevillea Avenue, St. Ives, New South Wales 2075, Australia, email jurgenotto@optusnet.com.au 2 213 Wild Horse Creek Drive, Simpsonville, SC 29680-6513, USA, email platycryptus@yahoo.com

A phylogenetic classification of jumping spiders (Araneae: Salticidae)

Abstract: The classification of jumping spiders (Salticidae) is revised to bring it into accord with recent phylogenetic work. Of the 610 recognized extant and fossil genera, 588 are placed at least to subfamily, most to tribe, based on both molecular and morphological information. The new subfamilies Onomastinae, Asemoneinae, and Eupoinae, and the new tribes Lapsiini, Tisanibini, Neonini, Mopsini, and Nannenini, are described. A new unranked clade, the Simonida, is recognized. Most other family-group taxa formerly ranked as subfamilies are given new status as tribes or subtribes. The large long-recognized clade recently called the Salticoida is ranked as a subfamily, the Salticinae, with the name Salticoida reassigned to its major subgroup (the sister group to the Amycoida). Heliophaninae Petrunkevitch and Pelleninae Petrunkevitch are considered junior synonyms of Chrysillini Simon and Harmochirina Simon respectively. Spartaeinae Wanless and Euophryini Simon are preserved despite older synonyms. The genus...

Splendid coloration of the peacock spider Maratus splendens.

Abstract: Jumping spiders are well known for their acute vision and often bright colours. The male peacock spider Maratus splendens is richly coloured by scales that cover the body. The colours of the white, cream and red scales, which have an elaborate shape with numerous spines, are pigmentary. Blue scales are unpigmented and have a structural colour, created by an intricate photonic system consisting of two chitinous layers with ridges, separated by an air gap, with on the inner sides of the chitin layers an array of filaments. We have characterized the optical properties of the scales by microspectrophotometry, imaging scatterometry and light and scanning electron microscopy. Optical modelling revealed that the filament array constitutes a novel structural coloration system, which subtly fine tunes the scale reflectance to the observed blue coloration.

Doppler shift generated by a moving diffraction grating under incidence by polychromatic diffuse light

Abstract: We consider the spectral response of moving diffraction gratings, in which the incident light extends over a broad angular range and where the diffracted light is observed from a specific angle. We show that the dispersion relation between the frequency perceived by an observer who is looking at a moving grating and the incident frequency can exhibit some unique features, such as a flat band (i.e., a local minimum). An observer can see the light diffracted into a non-specular diffraction order from a multitude of incident light rays and the angle of incidence of each ray is frequency-dependent, as a consequence, when the grating is moving, each incident ray experiences a Doppler shift in frequency that depends on its angle of incidence. We find that remarkable features appear near a Wood anomaly where the angle of incidence, for a given diffraction angle, can change very quickly with frequency. This means that light of multiple frequencies and incident from multiple angles can be mixed by the motion of the grating into the same diffracted ray and their frequencies can be compressed into a narrower range. The existence of a flat band means that a moving grating can be used as a device to increase the intensity of the perceived diffracted light due to spectral compression. The properties of a grating in motion in sunlight can also be relevant to the study of naturally occurring gratings which are typically in oscillatory motion.

Phylogenomics of peacock spiders and their kin (Salticidae: Maratus), with implications for the evolution of male courtship displays

Abstract: 1Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA 94720-3114, USA 2Department of Biology, San Diego State University, San Diego, CA 92182-4614, USA 3Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720-3160, USA 4Ecology & Evolution Research Centre, School of Biological, Earth & Environmental Sciences, UNSW, Sydney, 2052, NSW, Australia 5Collections and Research, Western Australian Museum, 49 Kew Street, Welshpool, 6106, Western Australia, Australia