Reproductive dependence of a branchiobdellidan annelid on its crayfish host: confirmation of a mutualism

Crustaceana ◽  
2015 ◽  
Vol 88 (4) ◽  
pp. 385-396 ◽  
Author(s):  
Robert P. Creed ◽  
Robert P. Creed ◽  
Joshua D. Lomonaco ◽  
Robert P. Creed ◽  
Joshua D. Lomonaco ◽  
...  

The ectosymbiotic branchiobdellidan Cambarincola ingens Hoffman, 1963 can increase the growth and reduce mortality of the crayfish Cambarus chasmodactylus James, 1966. These results suggest that these two species are engaged in a cleaning symbiosis mutualism. However, the potential benefits C. ingens derives from the association, specifically its reproductive dependence on the crayfish, have not been examined experimentally. We conducted two experiments to determine if C. ingens was reproductively dependent on C. chasmodactylus. In the experiments, worms only laid cocoons on live crayfish. Also, significantly more cocoons were laid on larger crayfish which was consistent with a survey of worm and cocoon abundance on crayfish collected from a local river. These results suggest that C. ingens is dependent on its crayfish host for reproduction. The association between C. chasmodactylus and C. ingens is a mutualism, at least under environmental conditions in which crayfish survival and growth are enhanced by the worms.

1986 ◽  
Vol 43 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Peter F. Shacklock ◽  
James S. Craigie

Commercial aquaculture of Chondrus crispus in eastern Canada required the development of reliable methods for ensuring the winter survival of a healthy, vegetative inoculum. Two procedures were investigated. Agitated cultures of C. crispus (stocking density <6 kg∙m−2) in running seawater grew at average rates of 0.21–0.34 kg∙m−2∙wk−1 during two winters under natural irradiance. Cultures maintained in undisturbed, outdoor tanks of seawater over three winters showed little or no net production; however, survival was excellent provided that the stocking density remained below approximately 10 kg∙m−2. The plants were capable of resuming growth when environmental conditions improved. We found no difference in the responses of the several haploid and diploid isolates examined. Large vegetative inocula required for commercial aquaculture can be maintained simply and reliably in tanks of clean seawater if they are undisturbed and an ice cover is allowed to form.


Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 159
Author(s):  
Álvaro Montesinos ◽  
Grant Thorp ◽  
Jérôme Grimplet ◽  
María José Rubio-Cabetas

The cropping potential of almond (Prunus amygdalus (L.) Batsch, syn P. dulcis (Mill.)) cultivars is determined by their adaptation to edaphoclimatic and environmental conditions. The effects of scion–rootstock interactions on vigor have a decisive impact on this cropping success. Intensively planted orchards with smaller less vigorous trees present several potential benefits for increasing orchard profitability. While several studies have examined rootstock effects on tree vigor, it is less clear how rootstocks influence more specific aspects of tree architecture. The objective of this current study was to identify which architectural traits of commercially important scion cultivars are influenced by rootstock and which of these traits can be useful as descriptors of rootstock performance in breeding evaluations. To do this, 6 almond cultivars of commercial significance were grafted onto 5 hybrid rootstocks, resulting in 30 combinations that were measured after their second year of growth. We observed that rootstock choice mainly influenced branch production, but the effects were not consistent across the different scion–rootstock combinations evaluated. This lack of consistency in response highlights the importance of the unique interaction between each rootstock and its respective scion genotype.


2008 ◽  
Vol 53 (No. 5) ◽  
pp. 203-209 ◽  
Author(s):  
M. Sarvaš ◽  
P. Pavlenda ◽  
E. Takáčová

In this study results of hydrogel application in reclamations are presented. The application of hydrogel affected the survival of pine seedlings during two vegetation periods after planting. Double application of STOCKOSORB AGRO (gel) on the root system after lifting caused an about 19% higher survival rate compared to control variants. The application of 7 g/planting hole of STOCKOSORB MICRO granules caused overdosage and plant mortality. The application of hydrogel granules is simple but it is very complicated not to cause the overdosage because of the very high swelling capacity of hydrogel. Research should be carried out to determine suitable hydrogel application rates for different environmental conditions and tree species. To design a technology with regard to the economic effectiveness of application will be a very important task.


2004 ◽  
Vol 67 (8) ◽  
pp. 1676-1681 ◽  
Author(s):  
XIUPING JIANG ◽  
MAHBUB ISLAM ◽  
JENNIE MORGAN ◽  
MICHAEL P. DOYLE

The survival and growth of Listeria monocytogenes in soil amended with bovine manure was studied under different environmental conditions of temperature, nutrients, and soil microflora. Autoclaved soil was compared with unautoclaved soil for assessing the influence of competitive soil microflora on the survival of L. monocytogenes. Initial L. monocytogenes cell numbers of 5 to 6 log CFU/g survived for up to 43, 43, and 14 days in manure-amended autoclaved soil at 5, 15, and 21°C, respectively. In manure-amended unautoclaved soil, the pathogen was detectable for up to 43, 21, and 21 days at 5, 15, and 21°C, respectively. L. monocytogenes was inactivated more rapidly in autoclaved soil amended with manure at a manure/soil ratio of 1:10 than in the more dilute (1:100) manure in soil samples at both 15 and 21°C. However, in manure-amended unautoclaved soil, L. monocytogenes survived longer in samples with ratios of 1:10 than in the more dilute (1:100) manure-amended soil. The persistence of L. monocytogenes for several weeks in manure-amended soil suggests listeriae could be transmitted through soil to fresh produce or to shoes, clothing, and hands of field workers, especially during the cold months.


OCL ◽  
2020 ◽  
Vol 27 ◽  
pp. 51
Author(s):  
Stan Chabert ◽  
Christopher Sénéchal ◽  
André Fougeroux ◽  
Jérémy Pousse ◽  
Fabien Richard ◽  
...  

The sunflower crop provides an important honey flow for beekeepers. In France, beekeepers observed a decrease in honey yield from this crop these past years compared to the 1980s–1990s. They suspect the new cultivars to be less productive in nectar compared to the older ones, but no data is available to support this, and it is known that climate conditions have a strong impact on nectar secretion. This study aimed to explore the effect of abiotic environmental conditions on nectar secretion in sunflower, as well the range of variation of this secretion in a sample of current cultivars. Thirty-four current sunflower hybrid cultivars were sampled in test plots for their nectar secretion under varying conditions of temperature, air humidity and soil moisture. Air humidity controlled the sugar concentration of nectar, and thus its volume. To study nectar secretion independently from this effect, analyses subsequently focused on nectar sugar mass per floret. The nectar sugar mass increased with temperature up to an optimum of 32 °C, while the variation range of soil water tension was not sufficient to detect an effect on nectar sugar mass. This varied by up to 100% among the 34 cultivars (from 101 to 216 μg sugar per staminate floret in average), with a similar range to those reported in the literature for older cultivars. Likewise, oleic cultivars, a new type introduced since the early 2000s, were found to secrete the same amounts of nectar as linoleic cultivars, an older conventional type. The more self-fertile cultivars also showed no reduction in nectar secretion. Finally, we tested the method that measures the nectar gross secretion rate in one hybrid, and we observed that this hybrid secreted in average 28 μg sugar per hour per staminate floret. The potential benefits of this method were discussed.


Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.


2014 ◽  
Vol 4 (1) ◽  
pp. 23-29
Author(s):  
Constance Hilory Tomberlin

There are a multitude of reasons that a teletinnitus program can be beneficial, not only to the patients, but also within the hospital and audiology department. The ability to use technology for the purpose of tinnitus management allows for improved appointment access for all patients, especially those who live at a distance, has been shown to be more cost effective when the patients travel is otherwise monetarily compensated, and allows for multiple patient's to be seen in the same time slots, allowing for greater access to the clinic for the patients wishing to be seen in-house. There is also the patient's excitement in being part of a new technology-based program. The Gulf Coast Veterans Health Care System (GCVHCS) saw the potential benefits of incorporating a teletinnitus program and began implementation in 2013. There were a few hurdles to work through during the beginning organizational process and the initial execution of the program. Since the establishment of the Teletinnitus program, the GCVHCS has seen an enhancement in patient care, reduction in travel compensation, improvement in clinic utilization, clinic availability, the genuine excitement of the use of a new healthcare media amongst staff and patients, and overall patient satisfaction.


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