Bacteria forming light-organ symbiosis with deep-sea chlorophthalmid fishes (Aulopiformes: Chlorophthalmidae) are considered to belong to the species Photobacterium phosphoreum. The identification of these bacteria as P. phosphoreum, however, was based exclusively on phenotypic traits, which may not discriminate between phenetically similar but evolutionarily distinct luminous bacteria. Therefo...

Temperature effects on spectral properties of the two types of rod photoreceptors in toad retina, "red" and "green" rods, were studied in the range 0-38 degrees C. Absorbance spectra of the visual pigments were recorded by single-cell microspectrophotometry (MSP) and spectral sensitivities of red rods were measured by electroretinogram (ERG) recording across the isolated retina. The red-rod vis...

We tested the hypotheses that hypoxic toads (Bufo marinus) in a thermal gradient would select a lower than normal temperature and that this behavioral response would be beneficial. Under normoxic conditions, selected body temperature was 24.2 +/- 3.6 degrees C. When inspired O2 was 10% or less, mean selected temperature decreased to 15.3 +/- 2.4 degrees C. The theoretical advantages of hypoxia-...

Many anurans use their hindlimbs to generate propulsive forces during both jumping and swimming. To investigate the musculoskeletal dynamics and motor output underlying locomotion in such physically different environments, we examined patterns of muscle strain and activity using sonomicrometry and electromyography, respectively, during jumping and swimming in the toad Bufo marinus. We measured ...

Changes in the apical and basal membrane potentials and the resultant changes in the transepithelial potential were recorded from the isolated retinal pigment epithelium of the toad Bufo marinus while the potassium concentration superfusing the apical membrane was changed. Lowering apical potassium caused an initial apically-generated hyperpolarization that increased the transepithelial potenti...