Showing papers on "Uca pugilator published in 1969"
TL;DR: Female fiddler crabs showed unconditioned responses (usually, locomotor or ‘startle’ responses) when presented with brief tones from beneath a cardboard testing platform, suggesting that the crabs were responding to amplitude displacements of the platform rather than air pressures, at least at the lower frequencies.
24 citations
TL;DR: For the first time evidence is provided to show that substances capable of evoking pigment dispersion and pigment concentration in the leucophores of Uca are present in the eyestalks of Palaemonetes.
Abstract: 1 The relationships between the response of the leucophores in Uca pugilator and the concentration of extracts of eyestalks from Uca pugilator and Palaemonetes vulgaris were determined For the first time evidence is provided to show that substances capable of evoking pigment dispersion and pigment concentration in the leucophores of Uca are present in the eyestalks of Palaemonetes Contrary to the situation recorded previously for melanin-dispersing activity, extracts prepared directly in saline and the ethanol-soluble fractions of the eyestalks from Uca evoked nearly identical white pigment-dispersing activity at all dilutions tested2 White pigment-dispersing and -concentrating substances can both be demonstrated to be present in the ethanol-soluble fraction of the eyestalks of Uca as well as in the material directly extractable in water in spite of the fact that when these extracts are assayed immediately after preparation they evoke only white pigment dispersion because the white pigment-dispersing
6 citations
TL;DR: In this article, the Winkerkrabbe Uca pugilator bei 5° ± 1°C ergaben, das bei Individuen, deren Melanin nach Augenstielenentfernung maximal konzentriert wurde and sich in diesem Zustand erhielt bis zur Kalteuberfuhrung, ein Rhythmus der Melan-inwanderungen induziert werden kann.
Abstract: Augenstiellose Individuen der Winkerkrabbe Uca pugilator zeigten bei niedrigen Temperaturen (5°-9°C) eine geringfugige aber statistisch sehr signifikante Melanindispersion. Beobachtungen an augenstiellosen U. pugilator bei 5° ± 1°C ergaben, das bei Individuen, deren Melanin nach Augenstielenentfernung maximal konzentriert wurde und sich in diesem Zustand erhielt bis zur Kalteuberfuhrung, ein Rhythmus der Melaninwanderungen induziert werden kann. Augenstiellose Kontrollen, welche bei 22° ± 1°C und 32° ± 1°C gehalten wurden liesen keinen Rhythmus der Melaninwanderung erkennen. Bei kaltgehaltenen, augenstiellosen Krebsen war das Melanin von 10°° bis 13°° Uhr und von 20°° bis 01°° Uhr starker verteilt als zu anderen Tages- oder Nachtzeiten. Die Zeiten, zu denen Maximal- und Minimalwerte in der Melanindispersion auftraten, erwiesen sich als unabhanging von der Zeit zu der die Krebse erstmals den niedrigen Temperaturen ausgesetzt worden waren. Diese Beobachtungen werden in Zusammenhang mit der einschlagigen Literatur diskutiert.
4 citations
28 Dec 1969-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: Evidence is presented to indicate that the melanin-dispersing response evoked in eyestalksless crabs after injection of eyestalk extract increases with increase in the size of the crabs used in the assay.
Abstract: 1.
The influence of size on the response of melanophores in Uca pugilator from Alligator Point, Florida and West Falmouth, Massachusetts was determined.
2.
For the first time evidence is presented to indicate that the melanin-dispersing response evoked in eyestalkless crabs after injection of eyestalk extract increases with increase in the size of the crabs used in the assay.
3.
The blood of small crabs has a higher titer of melanin-concentrating substance than does the blood of large crabs. Consequently smaller crabs would be more readily able to antagonize injected melanin-dispersing hormone, resulting in a smaller response. In addition, it is possible that the sensitivity of the chromatophores may increase with increase in size of the crab.
2 citations