scispace - formally typeset
Search or ask a question

Showing papers on "Uca pugilator published in 1970"


Journal ArticleDOI
TL;DR: It is concluded that serotonin acts primarily on the central nervous system to stimulate the release of a red pigment-dispersing hormone, whereas the red pigment’s hormone stimulates the erythrophores directly.

59 citations


Journal ArticleDOI
TL;DR: The direct responses of chromatophores to light stimuli have been observed in a wide diversity of organisms and the spectral sensitivity of the fin melanophores in isolated tails of the amphibian Xenopus laevis is determined.
Abstract: The direct responses of chromatophores to light stimuli have been observed in a wide diversity of organisms (Fingerman 1963; Van der Lek 1967). With very few exceptions, pigment dispersion occurs in bright light (visible and ultraviolet) and pigment concentration in darkness. For example, when melanophores of eyestalkless fiddler crabs Uca pugilator were exposed to sunlight, pigment dispersion occurred as a direct response to the illumination (Brown and Sandeen 1948). However, the relative spectral efficiency of this response is not known. As in the fiddler crab, bright illumination also causes pigment dispersion to occur in the chromatophores of the sea urchin Diadema setosum (Yoshida 1956). Using visible light alone, Yoshida (1957) reported a peak effectiveness for pigment dispersion in this sea urchin in the region 450-500 mnt. Van der Lek (1967) determined the spectral sensitivity of the fin melanophores in isolated tails of the amphibian Xenopus laevis. The pigment in these melanophores atypically concentrates when they are illuminated. With visible light, the wavelength of maximal sensitivity was 425 mp. Van der Lek also obtained

35 citations


Journal ArticleDOI
TL;DR: Lysergic acid diethylamide evokes strong concentration of the erythrophoric pigment in intact fiddler crabs, Uca pugilator, but does not evoke pigment concentration in the ERYthrophores of eyestalkless crabs or legs isolated from intact crabs.

24 citations


Journal ArticleDOI
M. Fingerman1
TL;DR: The possibility of a species specificity in the action of distal retinal pigment light‐adapting hormones in crustaceans is discussed.
Abstract: The distal retinal pigment in the fiddler crab, Uca pugilator, displays a circadian rhythm in constant darkness. The pigment approaches the fully light adapted position by day and the fully dark adapted position by night. This rhythm is presumably due at least to rhythmical release by day of a distal retinal pigment light‐adapting hormone. Extracts of eyestalks from Uca produce a light‐adaptational response in the crab, but extracts of eyestalks from the prawn, Palaemonetes vulgaris, do not produce a light‐adaptational response in the crab, but a dark‐adaptational response instead. In contrast, both types of extract produce a light‐adaptational response of the distal retinal pigment in Palaemonetes. The possibility of a species specificity in the action of distal retinal pigment light‐adapting hormones in crustaceans is discussed.

17 citations


Journal ArticleDOI
TL;DR: Extracts of radial nerves from the starfish were assayed for chromatophorotropic activity in the fiddler crab, Uca pugilator and indicated that the latter is different from the chrom atophorotropins which have been found in crustaceans.
Abstract: 1. Extracts of radial nerves from the starfish, Asterias amurensis, were assayed for chromatophorotropic activity in the fiddler crab, Uca pugilator. 2. The radial nerve extracts evoked pigment dispersion in the melanophores and pigment concentration in the leucophores and erythrophores of Uca. Gel filtration studies revealed that the chromatophorotropic material is different from the gamete-shedding substance. 3. Like chromatophorotropins in arthropod neural tissues, the chromatophorotropic material in the radial nerves appears to have a peptide nature. Chromatography on Bio-Gel P-6 and analysis of solubility properties indicate that the latter is different from the chromatophorotropins which have been found in crustaceans. 4. The possibility that these chromatophorotropic effects were caused by a single substance was discussed.

4 citations


Journal ArticleDOI
01 Nov 1970-Toxicon
TL;DR: Lyophilized venom of the alphabet cone, Conus spurius atlanticus, was tested on the crabs Uca sp.

1 citations