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Uca pugilator

About: Uca pugilator is a research topic. Over the lifetime, 376 publications have been published within this topic receiving 12303 citations.


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01 Jan 1984
TL;DR: Electrical stimulation of the isolated eyestalk of Uca pugilator induces the release of several peptides which affect epidermal chromatophores, but no red pigment dispersing hormone (RPDH) was detected at any voltage.
Abstract: Electrical stimulation of the isolated eyestalk of Uca pugilator induces the release of several peptides which affect epidermal chromatophores. Thresholds for release of these peptides were different, that for red pigment concentrating hormone (RPCH) being lowest, for black pigment dispersing hormone (BPDH) highest, and for black pigment concentrating hormone (BPCH) intermediate, but no red pigment dispersing hormone (RPDH) was detected at any voltage. Neurotransmitters, known to be present in crustacean central nervous systems, induced chromatophore dose dependent responses. Norepinephrine induced BPDH release, and dopamine induced both RPCH and BPCH release.

7 citations

Journal ArticleDOI
TL;DR: The extensor muscle and chela of unoperated and transplanted regenerated limbs from two species of Uca were examined to test the theory of neurotrophic control on crustacean muscle, finding that innervation alone controls the growth and differentiation of muscle.
Abstract: The extensor muscle and chela of unoperated and transplanted regenerated limbs from two species of Uca were examined to test the theory of neurotrophic control on crustacean muscle. Initially, tuberculation patterns, sensory hair number, and claw shape of the transplanted regenerated limb resembled those of the donor. Sarcomere lengths were donorlike except when the transplant was from male to female. Eventually the transplanted regenerated limb acquired some recipientlike features, although the claw shape and sarcomere length measurements of secondary regenerates resembled those of the donor. Because of these findings, it is no longer possible to hypothesize that innervation alone controls the growth and differentiation of muscle.

7 citations

Journal ArticleDOI
TL;DR: Of the three types of tissues analyzed, muscle showed the lowest pyruvate incorporation into FAA and almost none into protein, whereas hepatopancreas and “carcass” (all remaining tissues) exhibited more rapid turnover of both protein and FAA.
Abstract: 1. 1. The time course of in vivo incorporation of 3-[ 14 C]-pyruvate into free and protein-bound amino acids was studied in the fiddler crab, Uca pugilator , over a 72 hr period. 2. 2. Label was detected in alanine, glutamic acid, aspartic acid, glutamine, proline, and possibly serine, indicating that these are nonessential for this species. 3. 3. Peaks in total label content and specific activities of free amino acids (FAA) ∗ were observed within 4 hr after injection, with highest labeling in alanine and glutamic acid; however, significant amounts of 14 C were still present in the FAA after 72 hr. 4. 4. Of the three types of tissues analyzed, muscle showed the lowest pyruvate incorporation into FAA and almost none into protein, whereas hepatopancreas and “carcass” (all remaining tissues) exhibited more rapid turnover of both protein and FAA. 5. 5. Acid hydrolysis of FAA fractions from carcass and hepatopancreas released large amounts of some amino acids, especially glutamate and aspartate, from other TCA-soluble materials. However, only glutamate contained appreciable radiocarbon. 6. 6. The label distribution patterns found in Uca are consistent with those of most other crustaceans which have been studied.

7 citations

Journal ArticleDOI
TL;DR: The melanin-dispersing activity was related to the dielectric constants of the normal alcohols used in the following decreasing order: methanol>ethanol>propanol>butanol>amyl alcohol as mentioned in this paper.
Abstract: 1. Extracts of fresh, freeze-dried, and heat-dried eyestalks prepared directly in physiological saline evoked nearly identical melanin-dispersing responses. The highly active ethanol-soluble fraction extractable from fresh eyestalks ofUca was to a great extent unextractable after the eyestalks were freeze-dried, heat-dried, or pretreated with a variety of organic solvents, whereas the melanin-dispersing substance in the ethanol-insoluble fraction of the eyestalk was resistant to these treatments. The melanin-dispersing substance obtained by direct extraction of the eyestalk in water is more resistant to treatment with organic solvents than the substance present in the ethanol-soluble fraction. 2. The melanin-dispersing activities of the eyestalk material soluble in various solvents showed no overall relationship with the dielectric constants of the solvents used. However, the melanin-dispersing activity was related to the dielectric constants of the normal alcohols used in the following decreasing order: methanol>ethanol>propanol>butanol>amyl alcohol. 3. Ether and isopropyl ether destroyed most of the melanin-dispersing material present in the ethanol-soluble and water-soluble fractions of the eyestalk, possibly due to excessive oxidation. 4. The melanin-dispersing material in the ethanol-soluble fraction of the eyestalk is greatly destroyed by heat. In contrast, the melanin-dispersing material in the water-soluble fraction of the eyestalk is resistant to heat. 5. The possibility that two melanin-dispersing substances are present in the eyestalks ofUca is considered and discussed.

7 citations

Journal ArticleDOI
TL;DR: Examination of a population of fiddler crabs, Uca pugilator, revealed that the females were darker than the males, and the following investigation was undertaken to analyze the difference in coloration between the males and females.
Abstract: The degree of dispersion of the pigment in the melanophores of fiddler crabs, Uca spp., is influenced by a variety of factors. Carlson (1935) demonstrated that blanching resulting from melanin concentration occurred in Uca pugilator when the eyestalks were removed. Injection of extracts of the eyestalks caused the Uca to darken through dispersion of the pigment. Sandeen (1950) showed that the central nervous organs produced a factor that caused melanin dispersion. Fingerman (1956a) found a blood-borne hormone that concentrated the melanin in the chromatophores of Uca pugilator. Light, temperature, and background also influence the state of the pigment (Brown and Sandeen, 1948). The dispersion of the melanin increased with increase in the light intensity. The black pigment tended to concentrate with increase in temperature. An albedo response was also present. The black pigment tended to disperse on a black background and concentrate on a white background. Daily and tidal rhythms also determine the dispersion of the melanin. Abramowitz (1937) first described the daily rhythm. The Uca were dark by day and light by night. Brown and Webb (1949) and Webb (1950) elucidated the mechanism involved in shifting the phases of this rhythm. Superimposed upon the daily rhythm is a tidal rhythm (Brown, Fingerman, Sandeen and Webb, 1953; Fingerman, 1956b). This tidal rhythm leads to an increased degree of dispersion of the melanin approximately two hours later than the actual time of occurrence of the tides which are spaced 12.4 hours apart. In regions with semidiurnal tides this augmentation occurred only after the low tide, but in regions of diurnal tides this augmentation occurred after both high and low tides. Examination of a population of fiddler crabs, Uca pugilator, revealed that the females were darker than the males. The following investigation was undertaken to analyze the difference in coloration between the males and females.

7 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20211
20176
20162
20153
20146
20137