scholarly journals Changes in precipitation may alter food preference in an ecosystem engineer, the black land crab, Gecarcinus ruricola

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6818
Author(s):  
Iain J. McGaw ◽  
Travis E. Van Leeuwen ◽  
Rebekah H. Trehern ◽  
Amanda E. Bates
Keyword(s):  
Food Intake ◽  
Water Loss ◽  
Ecosystem Engineer ◽  
Nutrient Recycling ◽  
Multiple Choice ◽  
Body Water ◽  
Land Crab ◽  
Land Crabs ◽  
The Caribbean ◽  
Black Land

Gecarcinid land crabs are ecosystem engineers playing an important role in nutrient recycling and seedling propagation in coastal forests. Given a predicted future decline in precipitation for the Caribbean, the effects of dehydration on feeding preferences of the black land crab Gecarcinus ruricola were investigated. G. ruricola were offered novel food items of lettuce, apple, or herring to test for food choice based on water and nutritional (energetic) content in single and multiple choice experimental designs. The effect of dehydration was incorporated by depriving crabs of water for 0, 4, or 8 days, leading to an average body water loss of 0%, 9%, and 17%, respectively, (crabs survived a body water loss of 23% + 2% and 14–16 days without access to water). The results were consistent between the single and multiple choice experiments: crabs consumed relatively more apple and fish and only small amounts of lettuce. Overall, no selective preferences were observed as a function of dehydration, but crabs did consume less dry food when deprived of water and an overall lower food intake with increasing dehydration levels occurred. The decrease in feeding was likely due to loss of water from the gut resulting in the inability to produce ample digestive juices. Future climatic predictions suggest a 25–50% decline in rainfall in the Caribbean, which may lead to a lower food intake by the crabs, resulting in compromised growth. The subsequent reduction in nutrient recycling highlights possible long-term effects on coastal ecosystems and highlights the importance of future work on climate relative behavioral interactions that influence ecosystem function.

Prevalence, Serovars, and Antimicrobial Susceptibility of Salmonella Isolated from Blue Land Crabs (Cardisoma guanhumi) in Grenada, West Indies

2013 ◽  
Vol 76 (7) ◽  
pp. 1270-1273 ◽  
Author(s):  
ROSS PETERSON ◽  
HARRY HARIHARAN ◽  
VANESSA MATTHEW ◽  
SAM CHAPPELL ◽  
ROB DAVIES ◽  
...  
Keyword(s):  
Disc Diffusion ◽  
Land Crab ◽  
Land Crabs ◽  
Cardisoma Guanhumi ◽  
Amoxicillin Clavulanic Acid ◽  
Human Illness ◽  
Salmonella Serotypes ◽  
The Caribbean ◽  
The Individual ◽  
Diffusion Assay

Samples of intestine and hepatopancreas from 65 blue land crabs (Cardisoma guanhumi), a crustacean commonly consumed as a food item in Grenada, were collected from six geographic sites in Grenada and tested for Salmonella by enrichment and selective culture. The individual animal prevalence of Salmonella based on isolation was 17% (11 of 65), and all infected crabs were from three of the six sampled locations. Isolates were identified by serotyping as Salmonella enterica serovars Saintpaul (n = 6), Montevideo (n = 4), and Newport (n = 1). The intestines of all 11 infected crabs were positive for Salmonella, but only 7 of 11 hepatopancreas samples were positive for Salmonella, and these isolates were the same serovar as isolated from the matching intestine. These three Salmonella serovars are known to cause human illness in many countries, and in the Caribbean Salmonella Saintpaul has been frequently isolated from humans. In a disc diffusion assay, all isolates were susceptible to all 11 drugs tested: amoxicillin–clavulanic acid, ampicillin, cephalothin, chloramphenicol, ciprofloxacin, gentamicin, imipenem, neomycin, streptomycin, tetracycline, and trimethoprim-sulfamethoxazole. To our knowledge, this report is the first concerning isolation and antimicrobial susceptibilities of Salmonella serotypes from the blue land crab.

Effects of atropine on synthesis and secretion of pepsinogen in the rat

1960 ◽  
Vol 198 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Basil I. Hirschowitz ◽  
D. K. O'Leary ◽  
I. N. Marks
Keyword(s):  
Water Loss ◽  
Indirect Evidence ◽  
Atropine Sulfate ◽  
Body Water ◽  
Limiting Factors ◽  
Subcutaneous Injections ◽  
Pylorus Ligation ◽  
Pepsinogen Secretion ◽  
Water Secretion ◽  
Rate Limiting

Simultaneous measurements of gastric juice pepsin and stomach mucosal pepsinogen were made in groups of pylorus-ligated rats at intervals from 2 to 24 hours to examine the effects of atropine sulfate (20 mg/100 gm/8 hrs.) on pepsinogen secretion and synthesis. Animals given subcutaneous injections of water served as controls. Atropine caused a marked reduction in pepsinogen secretion and a concomitant accumulation of pepsinogen in the mucosa which increased with time to a plateau; pylorus ligation had the opposite effect, indicating that atropine effected the reduction in secretion of pepsinogen by blocking the release of pepsinogen from peptic cells. In untreated rats the hematocrit increased proportionately to presumed body water loss, but in the atropine-treated rats the hematocrit failed to increase to the same degree for equivalent body water loss. Indirect evidence is presented to suggest that the rate of water secretion may be one of the rate-limiting factors in pepsinogen secretion. Although synthesis of pepsinogen can proceed without secretion, correlation of the rates of synthesis with those of secretion suggested that the rate of synthesis could be increased by an increased rate of secretion.

scholarly journals Flexibility in basal metabolic rate and evaporative water loss among hoopoe larks exposed to different environmental temperatures

2000 ◽  
Vol 203 (20) ◽  
pp. 3153-3159 ◽  
Author(s):  
J.B. Williams ◽  
B.I. Tieleman
Keyword(s):  
Food Intake ◽  
Metabolic Rate ◽  
Body Mass ◽  
Cold Exposure ◽  
Basal Metabolic Rate ◽  
Water Loss ◽  
Energy Demand ◽  
Exposure Group ◽  
Internal Organs ◽  
Evaporative Water

The ‘energy demand’ hypothesis for short-term adjustments in basal metabolic rate (BMR) posits that birds adjust the size of their internal organs relative to food intake, a correlate of energy demand. We tested this hypothesis on hoopoe larks (Alaemon alaudipes), inhabitants of the Arabian desert, by acclimating birds for 3 weeks at 15 degrees C and at 36 degrees C, then measuring their BMR and total evaporative water loss (TEWL). Thereafter, we determined the dry masses of their brain, heart, liver, kidney, stomach, intestine and muscles of the pectoral region. Although mean body mass did not differ initially between the two groups, after 3 weeks, birds in the 15 degrees C group had gained mass (44.1+/−6.5 g), whereas larks in the 36 degrees C group had maintained a constant mass (36.6+/−3.6 g; means +/− s.d., N=6). Birds in the 15 degrees C group had a mean BMR of 46.8+/−6.9 kJ day(−1), whereas birds in the 36 degrees C group had a BMR of 32.9+/−6.3 kJ day(−1), values that were significantly different when we controlled for differences in body mass. When measured at 35 degrees C, larks in the cold-exposure group had a TEWL of 3.55+/−0.60 g H(2)O day(−)(1), whereas TEWL for birds in the 36 degrees C group averaged 2.23+/−0.28 g H(2)O day(−1), a difference of 59.2%. Mass-independent TEWL differed significantly between groups. Larks in the 15 degrees C group had a significantly larger liver, kidney and intestine than larks in the 36 degrees C group. The total increase in organ mass contributed 14.3% towards the total mass increment in the cold exposure group. Increased food intake among larks in the cold group apparently resulted in enlargement of some of the internal organs, and the increase in mass of these organs required a higher rate of oxygen uptake to support them. As oxygen demands increased, larks apparently lost more evaporative water, but the relationship between increases in BMR and TEWL remains unresolved.

scholarly journals The Aphelenchus avenae genome highlights evolutionary adaptation to desiccation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xuehua Wan ◽  
Jennifer A. Saito ◽  
Shaobin Hou ◽  
Scott M. Geib ◽  
Anton Yuryev ◽  
...  
Keyword(s):  
Water Loss ◽  
Intrinsically Disordered Proteins ◽  
Early Stage ◽  
Body Water ◽  
Disordered Proteins ◽  
Gene Duplications ◽  
Intrinsically Disordered ◽  
Genome Wide ◽  
Aphelenchus Avenae ◽  
Species Specific

AbstractSome organisms can withstand complete body water loss (losing up to 99% of body water) and stay in ametabolic state for decades until rehydration, which is known as anhydrobiosis. Few multicellular eukaryotes on their adult stage can withstand life without water. We still have an incomplete understanding of the mechanism for metazoan survival of anhydrobiosis. Here we report the 255-Mb genome of Aphelenchus avenae, which can endure relative zero humidity for years. Gene duplications arose genome-wide and contributed to the expansion and diversification of 763 kinases, which represents the second largest metazoan kinome to date. Transcriptome analyses of ametabolic state of A. avenae indicate the elevation of ATP level for global recycling of macromolecules and enhancement of autophagy in the early stage of anhydrobiosis. We catalogue 74 species-specific intrinsically disordered proteins, which may facilitate A. avenae to survive through desiccation stress. Our findings refine a molecular basis evolving for survival in extreme water loss and open the way for discovering new anti-desiccation strategies.

Effects of dehydration on body-water distribution in desert kangaroos

1975 ◽  
Vol 229 (1) ◽  
pp. 251-254 ◽  
Author(s):  
MJ Denny ◽  
TJ Dawson
Keyword(s):  
Plasma Volume ◽  
Water Loss ◽  
Water Distribution ◽  
Extracellular Volume ◽  
Body Water ◽  
Red Kangaroo ◽  
Ecological Implications ◽  
Body Fluid Compartments ◽  
Fluid Compartments ◽  
Total Body

The effect of dehydration on the distribution of water in the bodies of two species of desert kangaroos, the red kangaroo Megaleia rufa and the euro Macropus robustus, has been examined. The volumes of various body-fluid compartments were determined in normally hydrated animals and then after the kangaroos had been dehydrated until body weight declined to 80% of the initial weight. The fluid compartments examined were total body water, plasma volume, intracellular volume (cellular and gut water), and extracellular volume. Both species were camel-like in their response to dehydration in that plasma volume was maintained in both species, falling by only 8.3% in red kangaroos and 7.4% in euros. The pattern of water loss from other compartments differed between species, particularly gut water loss. This compartment, which includes the large rumenlike fore stomach, contributed 56% of the total water loss of red kangaroos but only 22% of the loss from euros. The ecological implications of the preferential maintenance of gut water by the sedentary, cave-dwelling euros have been discussed.

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