Showing papers on "Uca pugilator published in 1981"
TL;DR: The feeding responses of the sand fiddler crab, Uca pugilator (Bosc), to various chemical and living food sources were determined using sand substrates and synergy interactions were observed in the stimulatory capacities of amino acids, amino acids + sugars, and living organisms.
86 citations
TL;DR: Rhythmic larval release on the nighttime high tide may be adaptive as a predator-avoidance mechanism for adult gravid females.
Abstract: Gravid female Uca pugilator (Bosc) maintained in conditions of 14h L: 10h D light regime and constant temperature without simulated tides showed a significant positive correlation between time of hatch and time of the nighttime high tide. Light: Dark experiments showed no entrainment by LD cues. Larval hatching was delayed until dark when high tide occurred between 1900 and 2130 hrs. Hatch time was a positive linear function of the time of the nighttime high tide when high tide occurred after 2130 hrs. Time of hatch was delayed by the light period on days lacking a nighttime high tide. Experiments conducted under constant light (LL) and temperature, without simulated tides, indicated a persistent free-running rhythm of approximately 25 h 03 min, suggesting an endogenous timer. Rhythmic larval release on the nighttime high tide may be adaptive as a predator-avoidance mechanism for adult gravid females.
68 citations
TL;DR: Findings of this study suggest that deposit-feeding is an important adjunct to predatory behavior in ghost crabs.
62 citations
TL;DR: The phase relationship of the two processes appears to be regulated in an antagonistic manner as those eyestalk-ablated lobsters exhibiting an accelerated molting cycle show correspondingly small gonadal development while those showing great gonadal growth do not exhibit accelerated molts.
50 citations
TL;DR: The results are consistent with the hypothesis that norepinephrine exerted its effect by acting on the central nervous system to trigger the release of melanin-dispersing hormone.
Abstract: Norepinephrine produces dose-related pigment dispersion in the melanophores of intact and eyestalkless fiddler crabs, Uca pugilator, but has no effect on the melanophores in isolated legs. 2. The effects of agonists and antagonists of norepinephrine on the rates of melanin dis- persion and concentration were determined. 3. The results are consistent with the hypothesis that norepinephrine exerted its effect by acting on the central nervous system to trigger the release of melanin-dispersing hormone. Migration of the pigment in the chromatophores of the fiddler crab Uca pugi- lator is hormonally regulated (Carlson, 1935; Sandeen, 1950; Brown, 1950; Fin- german, 1956a). A series of experiments performed with this crab has revealed that release of red pigment-dispersing hormone is triggered by 5-hydroxytrypt- amine (=serotonin) (Rao and Fingerman, 1970b) whereas release of red pigment- concentrating hormone is triggered by dopamine (Fingerman and Fingerman, 1977). However, no one has as yet identified a neurotransmitter substance which appears to be involved in triggering release of melanin-dispersing hormone (MDH), melanin-concentrating hormone (MCH), white pigment-dispersing hor- mone, or white pigment-concentrating hormone in any species of fiddler crab. Abramowitz and Abramowitz (1938) tested both acetylcholine and epinephrine on melanophores of Uca pugilator, and reported that they had no effect in either producing dispersion or aggregation of the pigment in these cells. Although Bau- chau and Mengeot (1966) found that 5-hydroxytryptamine will produce dispersion of the pigment in the melanophores of the shore crab Carcinus maenas, Rao and Fingerman (1970a) observed that this compound has no such effect on the me- lanophores of Uca pugilator. Presented below are the results of a series of ex- periments which led to identification of norepinephrine as a neurotransmitter substance that appears to be involved in triggering release of MDH in Uca pu- gilator. Experiments were also performed to identify a neurotransmitter sub- stance that might be involved in release of white pigment-dispersing hormone, but these were unsuccessful.
42 citations
TL;DR: The procedure described in the chapter uses the glands from 8000 crabs, received in shipments of 1000 each, to produce approximately 100-150 mg of homogeneous crab protease from the glands of 8000 fiddler crabs.
Abstract: Publisher Summary This chapter presents the procedure for purification and assaying of crab collagenolytic protease. The procedure described in the chapter uses the glands from 8000 crabs, received in shipments of 1000 each. The purification steps are following: preparation of acetone powder; first gel filtration; ion-exchange chromatography; hydroxyapatite chromatography; second gel filtration. This procedure produces approximately 100-150 mg of homogeneous crab protease from the glands of 8000 fiddler crabs. The enzyme is stable for several months in slightly acidic solution (pH -6.0) at –20°C, and can be stored indefinitely as a lyophilized powder. Crab collagenase can be assayed specifically for collagenolytic activity with a standard assay, which quantitates the release of soluble [14C]glycine-containing peptides from native reconstituted guinea pig skin collagen fibrils, or spectrophotometrically by following esterase or amidase activity with synthetic substrates.
32 citations
TL;DR: P pigment dispersion in all three chromatophore types is induced and potentiated and hormone-induced dispersion is inhibited in a dose dependent manner in isolated legs of U. pugilator.
22 citations
TL;DR: The results were consistent with the hypotheses that 5-hydroxytryptamine triggers release of a red pigment-dispersing hormone and that dopamine triggersRelease of aRed pigment-concentrating hormone in Uca pugilator.
20 citations
TL;DR: Fluoxetine potentiated and LY53857 antagonized 5-HT- and iproniazid-induced red pigment dispersion in crabs kept on a white background, consistent with the hypothesis that5-HT triggers the release of red pigment-dispersing hormone in Uca pugilator.
15 citations
TL;DR: The results are consistent with the hypothesis that norepinephrine is the neurotransmitter which triggers release of melanin-dispersing hormone in U. pugilator.
15 citations