Ammonia dynamics during and after prolonged emersion in the freshwater clam Corbicula fluminea (Müller) (Bivalvia: Corbiculacea)

1991 ◽  
Vol 69 (3) ◽  
pp. 676-680 ◽  
Author(s):  
Roger A. Byrne ◽  
Thomas H. Dietz ◽  
Robert F. McMahon

Hemolymph ammonia content during emersion and ammonia fluxes on reimmersion were examined in the freshwater bivalve Corbicula fluminea (Müller). Hemolymph ammonia levels remained at pre-emersion levels over a 5-day emersion period at 25 °C, but thereafter levels increased prior to death. On resubmergence after 3 days emersion, the initial rates of ammonia excretion were low and took 15 h to reach maximum levels. Duration of emergence did not affect postemergence ammonia excretion rates in individuals emersed for less than 3–4 days. These results indicate a lack of ammonia accumulation in aerially exposed specimens. Rather, C. fluminea appeared to suppress protein catabolism during emergence and avoided ammonia accumulation. Death on emergence occurred coincidentally with an increase in ammonia accumulation. After reimmersion, the delay in development of ammonia efflux maxima may represent metabolic "switching" from catabolism dominated by nonprotein energy stores to one partially supported by protein. Suppression of protein catabolism in air is an adaptation to the prolonged and unpredictable emergence not previously reported for any freshwater species.

1995 ◽  
Vol 52 (8) ◽  
pp. 1761-1767 ◽  
Author(s):  
David W. Aldridge ◽  
Barry S. Payne ◽  
Andrew C. Miller

Mussels were acclimated to each of four experimental temperatures (20, 24, 28, and 32 °C) for 30 days. Mussels averaged 10.29 mg tissue dry weight. Oxygen consumption rates at 32 °C were 3.65 times larger than consumption rates at 20 °C (p < 0.01). Ammonia excretion rates at 32 °C were 4.9 times greater than those at 20 °C (p < 0.01). O:N ratios were >60 at 20 and 24 °C but declined (p < 0.01) at 28 and 32 °C to <40. Filtration rates, an estimate of feeding rates, were not significantly different at 20 and 24 °C (p > 0.50) but declined at 28 and 32 °C (p < 0.01). Filtration rates at 32 °C were only 27% of the rates at 20 °C. These results indicate that (i) the metabolic expenditure of Dreissena polymorpha rose 265% as the temperature rose from 20 to 32 °C, (ii) metabolism relied more heavily on lipids and carbohydrates at 20 and 24 °C while protein catabolism increased at 28 and 32 °C, and (iii) the potential feeding rates of D. polymorpha declined by 73% as temperature rose from 20 to 32 °C. Above 28 °C D. polymorpha was unable to match energy expenditures with concurrent food intake and forced to rely on stored fuels.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tongqing Zhang ◽  
Jiawen Yin ◽  
Shengkai Tang ◽  
Daming Li ◽  
Xiankun Gu ◽  
...  

AbstractThe Asian Clam (Corbicula fluminea) is a valuable commercial and medicinal bivalve, which is widely distributed in East and Southeast Asia. As a natural nutrient source, the clam is rich in protein, amino acids, and microelements. The genome of C. fluminea has not yet been characterized; therefore, genome-assisted breeding and improvements cannot yet be implemented. In this work, we present a de novo chromosome-scale genome assembly of C. fluminea using PacBio and Hi-C sequencing technologies. The assembled genome comprised 4728 contigs, with a contig N50 of 521.06 Kb, and 1,215 scaffolds with a scaffold N50 of 70.62 Mb. More than 1.51 Gb (99.17%) of genomic sequences were anchored to 18 chromosomes, of which 1.40 Gb (92.81%) of genomic sequences were ordered and oriented. The genome contains 38,841 coding genes, 32,591 (83.91%) of which were annotated in at least one functional database. Compared with related species, C. fluminea had 851 expanded gene families and 191 contracted gene families. The phylogenetic tree showed that C. fluminea diverged from Ruditapes philippinarum, ~ 228.89 million years ago (Mya), and the genomes of C. fluminea and R. philippinarum shared 244 syntenic blocks. Additionally, we identified 2 MITF members and 99 NLRP members in C. fluminea genome. The high-quality and chromosomal Asian Clam genome will be a valuable resource for a range of development and breeding studies of C. fluminea in future research.


Author(s):  
Neil E. Coughlan ◽  
Ross N. Cuthbert ◽  
Eoghan M. Cunningham ◽  
Stephen Potts ◽  
Diarmuid McSweeney ◽  
...  

AbstractSuppression of established populations of invasive alien species can be a complex and expensive process, which is frequently unsuccessful. The Asian clam, Corbicula fluminea (Müller, 1774), is considered a high impact invader that can adversely alter freshwater ecosystems and decrease their socioeconomic value. To date, C. fluminea continues to spread and persist within freshwater environments worldwide, despite repeated management attempts to prevent dispersal and suppress established populations. As extensive C. fluminea beds can often become exposed during low-water conditions, the direct application of hot or cold thermal shock treatments has been proposed as suitable mechanism for their control. Further, mechanical substrate disturbance may enhance the efficacy of thermal shock treatments by facilitating exposures to multiple layers of buried clams. In the present study, we advanced these methods by assessing combined applications of both hot and cold thermal shock treatments for control of C. fluminea, using steam spray (≥100 °C; 350 kPa), low- or high-intensity open-flame burns (~1000 °C) and dry ice (−78 °C). In a direct comparison of raking combined with hot thermal shock applications, both steam and high-intensity open-flame treatments tended to be most effective, especially following multiple applications. In addition, when hot thermal treatments are followed by a final cold shock (i.e. dry ice), steam treatments tended to be most effective. Further, when dry ice was applied either alone or prior to an application of a hot shock treatment, substantial if not complete C. fluminea mortality was observed. Overall, this study demonstrated that combined applications of hot and cold thermal shock treatments, applied following the disruption of the substrate, can substantially increase C. fluminea mortality compared to separate hot or cold treatments.


SpringerPlus ◽  
2014 ◽  
Vol 3 (1) ◽  
pp. 455 ◽  
Author(s):  
Bai-cai Xiao ◽  
Er-chao Li ◽  
Zhen-yu Du ◽  
Run-lan Jiang ◽  
Li-qiao Chen ◽  
...  

2013 ◽  
Vol 4 (4) ◽  
pp. 539 ◽  
Author(s):  
Ningbo Liao ◽  
Shiguo Chen ◽  
Xingqian Ye ◽  
Jianjun Zhong ◽  
Nian Wu ◽  
...  

2016 ◽  
Vol 76 (3) ◽  
pp. 718-725
Author(s):  
T. C. L. Silveira ◽  
A. M. S. Gama ◽  
T. P. Alves ◽  
N. F. Fontoura

Abstract This study aimed to model the habitat suitability for an invasive clam Corbicula fluminea in a coastal shallow lagoon in the southern Neotropical region (–30.22, –50.55). The lagoon (19km2, maximum deep 2.5m) was sampled with an Ekman dredge in an orthogonal matrix comprising 84 points. At each sampling point, were obtained environmental descriptors as depth, organic matter content (OMC), average granulometry (Avgran), and the percentage of sand (Pcsand). Prediction performance of Generalized Linear Models (GLM), Generalized Additive Models (GAM) and Boosted Regression Tree (BRT) were compared. Also, niche overlapping with other native clam species (Castalia martensi, Neocorbicula limosa and Anodontites trapesialis) was examined. A BRT model with 1400 trees was selected as the best model, with cross-validated correlation of 0.82. The relative contributions of predictors were Pcsand-42.6%, OMC-35.8%, Avgran-10.9% and Depth-10.8%. Were identified that C. fluminea occur mainly in sandy sediments with few organic matter, in shallow areas nor by the shore. The PCA showed a wide niche overlap with the native clam species C. martensi, N. limosa and A. trapesialis.


2013 ◽  
Vol 61 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Vicente Gomes ◽  
Maria José de Arruda Campos Rocha Passos ◽  
Arthur José da Silva Rocha ◽  
Thais da Cruz Alves dos Santos ◽  
Alex Sander Dias Machado ◽  
...  

Changes in environmental factors may deeply affect the energy budget of Antarctic organisms as many of them are stenothermal and/or stenohaline ectotherms. In this context, the aim of this study is to contribute to knowledge on variations in the energy demand of the Antarctic amphipod, Gondogeneia antarctica as a function of temperature and salinity. Experiments were held at the Brazilian Antarctic Station "Comandante Ferraz", under controlled conditions. Animals collected at Admiralty Bay were acclimated to temperatures of 0ºC; 2.5ºC and 5ºC and to salinities of 35, 30 and 25. Thirty measurements were made for each of the nine combinations of the three temperatures and three salinities, totalling 270 measurements. Metabolic rates were assessed by oxygen consumption and total nitrogenous ammonia excretion, in sealed respirometers. When acclimated to salinities 30 or 35, metabolic rates at 0ºC and 2.5ºC were very similar indicating a possible mechanism of metabolic compensation for temperature. At 5.0ºC, however, metabolic rates were always higher. Lower salinities enhanced the effects of temperature on metabolism and ammonia excretion rates. The physiological adaptations of individuals of G. antarctica suggest adaptive mechanisms for energy saving, adjusted to an environment with stable conditions of temperature and salinity. Little is known about the joint effects of salinity and temperature and this study is an important contribution to the understanding of the mechanism of polar organisms in their adaptation to both factors.


2019 ◽  
Vol 7 (1) ◽  
pp. 36-39
Author(s):  
Dee Koh Han ◽  
Faizuan Abdullah ◽  
Idanne Adilla Ibrahim ◽  
Nurul Inani Rozaki ◽  
Siti Nor Aini Md Nasir ◽  
...  

Corbicula fluminea, known as “etak” in Kelantan, Malaysia is a freshwater bivalve. This clam is widely consumed as traditional snack by the locals. However, lately there are numerous reports in local newspapers that claim “etak” to cause health effects due to eating contaminated “etak”. Hence, this study aims to determine the heavy metals concentration in fresh, smoked and exposed “etak” sold at the stall as a baseline study in order to develop a method for removing the heavy metals content in its tissues. This study involves sample collection in the stalls around Kelantan, sample preparations via acid digestion and heavy metal determination using Perkin Elmer PinAAcle 900F Atomic Absorption Spectrometer. The results showed the heavy metals (Cr, Zn, Mn and Cu) concentrations (µg/g) in all “etak” tissue were at different level for fresh (Cr: 1.02±0.35ppm, Zn: 74.57±2.76ppm, Mn: 40.22±9.96ppm and Cu: 15.27±1.41ppm), smoked (Cr: 0.42±0.02ppm, Zn: 54.62±17.83ppm, Mn: 50.13±2.31ppm and Cu: 20.94±8.81ppm) and exposed (Cr: 0.53±0.08ppm, Zn: 63.07±8.44ppm, Mn: 50.41±6.92ppm and Cu: 12.80±0.40ppm) samples. The results obtained were compared with the permissible limits set by Malaysian Food Regulations 1985 (Cu: 30.0ppm and Zn: 100.0ppm), FAO/WHO 1984 (Mn: 5.4ppm) and IAEA – 407 (Cr: 0.75ppm). For fresh “etak”, Zn and Cu concentration were below the standards, while Mn and Cr were exceeded the permissible limits. For smoked “etak” and exposed “etak” at stall, all heavy metals concentration were within the permissible limits, except Mn contents. This study successfully determine the baseline concentration of the heavy metals in “etak”.


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