Ghost Crab Ocypode Quadrata Research Articles

Burrows of Ocypode quadrata (Fabricius) as related to slopes of substrate surfaces

Diameter, dip and orientation of burrows of the ghost crab Ocypode quadrata (Fabricius) were measured in back-beach areas: dune faces, dune crests, swales, blowouts and washover fans. Slope direction of the substrate at each burrow site was also measured. Results support three conclusions. First, burrow diameter increases landward. Second, burrow dip is related more to topography than to distance from shoreline; burrows dip more steeply in flatter areas (swales, blowouts, washovers). Third, a causal relationship exists between burrow orientation (as measured by the direction in which apertures point) and substrate slope; contrary to previous conclusions, burrow orientation is unrelated to shoreline direction. Burrow apertures simply point in the same direction as substrate slopes. In fact, on landward faces of dunes, burrow apertures point away from shoreline.

Chemical stimulants of cheliped flexion behavior by the Western Atlantic ghost crab Ocypode quadrata (Fabricius)

Cheliped flexion behavior was used as a bioassay to measure the responses of the Western Atlantic ghost crab Ocypode quadrata (Fabricius) to pure and natural stimuli. Responses to mantle fluid of Geukensia demissa Dillwyn are based on heat stable components of < 1000 mol. wt. In each class of pure compounds the following were most stimulatory: butanoic acid, carboxylic acids; trehalose, carbohydrates; homarine, amines; asparagine, amino acids. The response to butanoic acid was the largest of any stimulus tested. Disaccharides were more stimulatory than their common monosaccharide component, glucose, and were significantly more potent than amines, except for homarine. Disaccharides, carboxylic acids, and most of the amines were significantly more stimulatory than any of the amino acids. Proteins were the least stimulatory in contrast to the tripeptide glutathione that elicited responses similar to amino acids. These chemical stimuli are components of both live and decomposing foods in the diet of this species. The wide response spectrum of this species may reflect its “plasticity” of foraging behavior

Uptake of Interstitial Water from Soil: Mechanisms and Ecological Significance in the Ghost Crab Ocypode quadrata and Two Gecarcinid Land Crabs

Mechanisms by which terrestrial crabs take up interstitial water from soil, limiting conditions and rates of uptake, and their ecological relevance in nature were examined in the ghost crab Ocypode quadrata. Comparisons were made with two species of land crabs (Gecarcinus lateralis and Cardisoma guanhumi). Rapid rehydration, by bulk uptake of water, occurs in desiccated individuals of all three species when sufficient moisture is present in soil, regardless of osmotic gradient. Slow rehydration from hypoosmotic soil moisture also occurs, particularly in G. lateralis, even when the water content is below the threshold for bulk uptake. Ocypode quadrata has the lowest threshold (<5% water) for bulk uptake from damp sand. Water is collected from soil spaces by capillary tufts of setae, drawn into the gill chamber by suction up to 76 mm Hg, and at least some of it passed to the mouth and swallowed. This mechanism provides water ad lib. anywhere the water table lies near the surface of sandy soil. The highly terrestrial land crab G. lateralis is less capable of producing suction and of extracting soil water in bulk. In this crab's natural habitat, burrow soil never contains sufficient water for bulk uptake to contribute significantly to water balance, although gradual "osmotic uptake" may be important. Cardisoma guanhumi, whose burrows contain a pool of water, presumably need not rely on uptake of soil water. Nevertheless, it possesses structures similar to, and soil-water extraction capabilities superior to, those of G. lateralis. The great terrestriality of the land crabs, particularly G. lateralis, cannot be attributed to highly developed mechanisms for taking up bulk water from soil. These species meet the challenge of water balance on land by relying on conservation, while ghost crabs emphasize water uptake.

Deposit-feeding by the ghost crab Ocypode quadrata (Fabricius)

Observations using a videotape system on a secluded, Georgia, barrier beach revealed that the ghost crab Ocypode quadrata (Fabricius) exhibits diurnal deposit-feeding behavior similar to that manifested by the sand fiddler crab Uca pugilator (Bosc). The only other ghost crabs reported to engage in deposit-feeding, Ocypode ceratophthalma and guadichaudii, use their chelae in a different manner than O. quadrata or Uca pugilator. Ocypode quadrata individuals collect more substratum per feeding motion and produce larger feeding pellets, aggregations of harvested but uningested substratum, than do sand fiddlers. The difference in feeding pellet size appears to be related to differences in buccal cavity size. Differences in Chl a concentrations between feeding pellets and unforaged substratum showed that O. quadrata is less efficient than Uca pugilator at extracting algae from the harvested substratum. However, ghost crabs can extract up to 70% of the available algae. Findings of this study suggest that deposit-feeding is an important adjunct to predatory behavior.

Applications of Crab-Burrow Orientation to Environmental Analysis: ABSTRACT

Burrows of the ghost crab Ocypode quadrata (Fabricius) are widespread in beaches of Texas and Georgia. The orientation of these burrows and the factors that influence it are potentially useful in recognizing and interpreting ancient beach environments, shoreline position and orientation, and direction of dominant winds. O. quadrata burrows generally slope downward away from the shoreline with branches being landward of the main shaft. This preferred orientation is controlled by the direction of onshore winds. During the short excavation period (several minutes), individual crabs burrow 45° to either side of the local downwind direction. The mean orientation of all ghost crab burrows over days or larger periods of time, however, corresponds to the mean onshore wind direction. Other factors that influence burrow orientation include temperature and local landforms. When air temperatures drop below 15.5°C, ghost crabs generally stay in their burrows and reduce their activity. In Texas and Georgia, winter winds of these temperatures are generally offshore winds and consequently have little effect on burrow orientation. Where fore-dune ridges exist, burrows are randomly oriented in the interdune flats owing to wind shadows. In other places, mean burrow orientation is parallel with geomorphic features such as swales which tend to funnel the wind in specific directions. A model of ghost crab-burrow orientation was developed from laboratory experiments that can be combined with wind data to predict field observations in modern beach environments. End_of_Article - Last_Page 466------------

Apparent Predation on the Mole Crab Emerita talpoida (Say) by the Ghost Crab Ocypode quadrata (Fabricius)

The ghost crab Ocypode quadrata (Fabricius) is both a scavenger and an active predator which can be seen prowling the sea wrack left by the tide, especially at night. Williams (1965) stated that the crabs often will feed upon beached fish and I have seen them consuming portions of dead bluefish and striped mullet. According to Fowler (1911), the crabs prey extensively upon amphipod beach fleas of Latreille's genus Talitrus (= Orchestia, Leach, Barnard 1969). Sprunt (1948) reported that in the Florida Keys, the crabs can successfully attack and kill newly hatched least and sooty terns. During October, 1974, I observed the nocturnal activities of 0. quadrata on the open beaches of Kill Devil Hills, North Carolina. While some crabs scavenged among the sea wrack, others wandered that part of the

Burrows of the Ghost Crab Ocypode Quadrata (Fabricius) on the Barrier Islands, South-Central Texas Coast

ABSTRACT Burrows of the grapsoid crab Ocypode quadrata (Fabricius) are important biogenic sedimentary structures on Texas barrier islands. Variation in the shape, diameter, length, orientation, and areal density of the burrows can be used to define subenvironments of the beach and foredune ridge. An increase in diameter, length, and morphological complexity of the burrows together with a decrease in burrow abundance from the upper foreshore to the back edge of the beach differentiate beach subzones. Greater burrow size and abundance and a simpler shape distinguish O. quadrata burrows in the dune mounds from burrows in the interdune flats of the foredune ridge. A preferred burrow orientation descending to the northwest in the backshore contrasts with a random orientation of burrow in the foredune ridge. Although the preferred orientation is away from the shoreline, factors not directly related to shoreline trend may be responsible.

SOME OBSERVATIONS ON THE GENERAL BIOLOGY OF THE LAND CRAB, CARDISOMA GUANHUMI (LATREILLE), IN SOUTH FLORIDA

Previous article No AccessJournal ArticlesSOME OBSERVATIONS ON THE GENERAL BIOLOGY OF THE LAND CRAB, CARDISOMA GUANHUMI (LATREILLE), IN SOUTH FLORIDACHARLES A. GIFFORDCHARLES A. GIFFORD Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Biological Bulletin Volume 123, Number 1August 1962 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.2307/1539516 Views: 123Total views on this site Citations: 9Citations are reported from Crossref © 1962 Marine Biological LaboratoryPDF download Crossref reports the following articles citing this article:Agnieszka M. Adamczewska and Stephen Morris Ecology and Behavior of Gecarcoidea natalis, the Christmas Island Red Crab, During the Annual Breeding Migration, The Biological Bulletin 200, no.33 (Sep 2016): 305–320.https://doi.org/10.2307/1543512Agnieszka M. Adamczewska and Stephen Morris Metabolic Status and Respiratory Physiology of Gecarcoidea natalis, the Christmas Island Red Crab, During the Annual Breeding Migration, The Biological Bulletin 200, no.33 (Sep 2016): 321–335.https://doi.org/10.2307/1543513 Agnieszka M. Adamczewska and Steve Morris Locomotion, Respiratory Physiology, and Energetics of Amphibious and Terrestrial Crabs A. M. Adamczewska and S. Morris, Physiological and Biochemical Zoology 73, no.66 (Jul 2015): 706–725.https://doi.org/10.1086/318099 Stuart M. Linton and Peter Greenaway The Nitrogen Requirements and Dietary Nitrogen Utilization for the Gecarcinid Land Crab Gecarcoidea natalis S. M. Linton and P. Greenaway, Physiological and Biochemical Zoology 73, no.22 (Jul 2015): 209–218.https://doi.org/10.1086/316735 Alan W. Pinder , and Allan W. Smits The Burrow Microhabitat of the Land Crab Cardisoma guanhumi: Respiratory/Ionic Conditions and Physiological Responses of Crabs to Hypercapnia, Physiological Zoology 66, no.22 (Sep 2015): 216–236.https://doi.org/10.1086/physzool.66.2.30163687 Thomas G. Wolcott , and Donna L. Wolcott Ion Conservation by Reprocessing of Urine in the Land Crab Gecarcinus lateralis (Freminville), Physiological Zoology 64, no.11 (Sep 2015): 344–361.https://doi.org/10.1086/physzool.64.1.30158528 C. Kumara Pillai , and T. Subramoniam Yolk Utilization as an Adaptive Strategy of Terrestrialization in the Freshwater Crab Paratelphusa hydrodromous (Herbst), Physiological Zoology 58, no.44 (Sep 2015): 445–457.https://doi.org/10.1086/physzool.58.4.30156019 Thomas G. Wolcott Uptake of Interstitial Water from Soil: Mechanisms and Ecological Significance in the Ghost Crab Ocypode quadrata and Two Gecarcinid Land Crabs, Physiological Zoology 57, no.11 (Sep 2015): 161–184.https://doi.org/10.1086/physzool.57.1.30155978JOHN H. CHRISTY ADAPTIVE SIGNIFICANCE OF SEMILUNAR CYCLES OF LARVAL RELEASE IN FIDDLER CRABS (GENUS UCA): TEST OF AN HYPOTHESIS, The Biological Bulletin 163, no.22 (Sep 2016): 251–263.https://doi.org/10.2307/1541264