Procambarus clarkia, besides known as spiny lobster, belongs to a crustaceous household that is called Decapoa. This order has 10,000 species. The different species are divided into two different superfamilies: Astacoidea and Parastacoidea. The Astacoidea, which contains households Astacidae and Cambaridae, occur in the Northern Hemisphere. The Parastacoidea, which contains household Parastacidae, inhabit the Southern Hemisphere. These households live in Europe, Australia, New Zealand, North and South America, and Asia.
Crayfish, which lack a H2O tight exoskeleton and have gills, set up settlements in aquatic, semi-aquatic, and high humidness countries. Approximately 10 per centum of crayfish are of the fresh H2O species. These crayfish are omnivores, intending they feed chiefly on aquatic flora, other invertebrates, and atoms of break uping works and animate beings. They are really susceptible to marauders during their stripling and station sheding province of their life.
Crayfish are classified as poikilotherms. Poikilotherms are defined as “ any alleged inhuman animate being ; that is, any carnal whose ordinance of organic structure temperature depends on external beginnings, such as sunshine or a het stone surface ” ( Encyclopedia Britannica ) . “ The organic structure temperatures of aquatic poikilotherms are normally really close to those of the H2O. Poikilotherms do non necessitate as much nutrient as warm-blooded animate beings ( endotherms ) of the same size, but most can non cover every bit good with cold milieus. ”
Crayfish are good topics for surveies on facets of “ excitation including placing neuromuscular junctions and their differences, axon types, musculus types, neurotransmitters, behaviour, and long term alteration of nervus and musculus types ” ( Stock, Todd ) . In this instance, the spiny lobster were used to mensurate CHH ( crustaceous hyperglycemic endocrine ) . This endocrine is released under times of emphasis and is transferred to the hemolymph ( circulative fluid ) . This endocrine is present at the terminal of the eyestalk, in an organ called the “ x-organ ” , of crustaceans. The x-organ is a group of neurosecretory cells. This endocrine is the more often seen endocrine in the eyestalk of the spiny lobster. The chief function of this endocrine is to keep the glucose degrees in the hemolymph. A similar endocrine, called glucagon, maintains the normal glucose degrees in the blood of worlds. This endocrine has the opposite consequence of insulin, intending it increases the glucose degrees in the blood.
In this lab, measurings of CHH are being taken from two different spiny lobster, one with eyes and one without. My void hypothesis is that there will be no alteration in the glucose degrees between these two specimens. My working hypothesis is that there will be a higher glucose degree in the sample taken from the spiny lobster with eyes.
Methods and Materials
In this lab, we used two different types of spiny lobster ( Carolina Biological Supply Burlington, NC ) , one with eyes and one without eyes ( the eyes had been antecedently removed by teacher ) . All together, with 2009 and 2010 information, there were a sum of 12 braces of spiny lobster. The brace of crayfish were match in size. This was so you did n’t hold one little spiny lobster and one that was really big. Chloroform was used to set the spiny lobster under emphasis. Ringer ‘s solution ( Department of Biology and Environmental Science ) , which is made of 12g NaCl, 0.4g KCl, 1.5g CaCl2, 0.5g MgCl2, 0.17g NaHCO3 into 700 ml H2O, was put into the spiny lobster after taking some hemolymph. This solution substituted for the sum of hemolymph taken from the spiny lobster. Regular panpipes were used to recover the samples. A Spectronic 20 Plus was used to mensurate the optical density degrees.
With each spiny lobster, we held it from behind, on each side of the cephalothorax. We so held the tail down while person else inserted a syringe and drew out ~0.1 milliliter of hemolymph. Immediately after the hemolymph was taken, ~0.1 milliliter of Ringer ‘s solution was inserted into the spiny lobster. The hemolymph sample was so placed into a little trial tubing. This was done to each spiny lobster before emphasis. After taking the first sample of hemolymph, the spiny lobster were put in H2O to rest for approximately 15 proceedingss. Then, they were placed under emphasis in a little bath of trichloromethane for 20 seconds. They were so able to rest in the H2O for 15 more proceedingss. After they rested for 15 proceedingss, we took another sample of hemolymph and replaced it with Ringer ‘s solution. After all of our samples were taken and put into little trial tubings, we made a space ( ~0.1 milliliter Ringer ‘s solution and ~1.5 mL enzyme solution ) and a glucose criterion ( ~0.1 milliliter glucose, ~0.1 mL Ringer ‘s solution, and ~1.5 mL enzyme solution ) . To each of the tubings of hemolymph, we added ~1.5 mL enzyme solution ( Department of Biology and Environmental Science ) . We them placed the tubings in a H2O bath of 37A° C for 30 proceedingss. After the tubings were taken out of the H2O bath, we placed the contents of each tubing in a separate cuvette. The cuvettes were so placed in the Spectronic 20 separately for mensurating the optical density of the samples. After these measurings were taken, the glucose concentration was calculated for each sample.
When ciphering the glucose, it appears that the spiny lobster that still had eyes had a higher concentration of glucose in their hemolymph than the spiny lobster without eyes. In each brace, the glucose degrees were higher in the spiny lobster with eyes. The degrees were even higher after the spiny lobster had been under emphasis instead than before emphasis with the spiny lobster that had eyes. The degrees seemed to be higher before emphasis with the spiny lobster that did non hold eyes. Mention to the tabular arraies above.
Based on the working hypothesis the information supports it. The blood concentration of glucose increased dramatically in the spiny lobster with eyes that were exposed to emphasize. The blood glucose of spiny lobster without eyes increased somewhat or non at all.
With the consequences that the category calculated, my hypothesis was supported. I hypothesized that the spiny lobster with eyes would hold a higher glucose degree than those that did non hold eyes. Thingss that could hold gone incorrect would be the timing, recovering the hemolymph, and doing the solutions. We may hold left the spiny lobster in the trichloromethane for excessively long or non long plenty. The spiny lobster could hold been at remainder for a longer sum of clip after being under emphasis which could hold caused a alteration in their glucose degrees. We could hold put the acerate leaf in excessively far or non far plenty. We could hold gotten the measurings of the solutions incorrect, either excessively small or excessively much of a certain ingredient. To do the experiment better, we could hold reduced the emphasis from outside beginnings, such as jabing the spiny lobster or trouble oneselfing them in general. We could hold had more replicates to acquire more measurings from. We besides could hold had more controls. We could hold taken a sample before we removed the eyes from the spiny lobster and possibly tried to give the endocrine back through injection. Overall the experiment was a success.
- “ poikilotherm. ” Encyclop?dia Britannica. 2010. Encyclop?dia Britannica Online. 05 Oct. 2010 & lt ; hypertext transfer protocol: //www.britannica.com/EBchecked/topic/1516418/ectotherm & gt ; .
- Bowen, R. 1999. Glucagon. hypertext transfer protocol: //www.vivo.colostate.edu/hbooks/pathphys/endocrine/pancreas/glucagon.html
- Stock, T. 1997. The Crayfish: background and related neurological research refering to Cheliped ( Claw ) research. hypertext transfer protocol: //www.biol.sc.edu/~vogt/courses/neuro/notes/crawfish-claw-todd2.pdf
- hypertext transfer protocol: //www.ncbi.nlm.nih.gov/pubmed/18281112
- Laboratory Manual for Introduction to Physiology
Example of a great lab study:
Effectss of the hyperglycemic endocrine on ordinance of the hemolymph glucose concentration in response to emphasize in Procambarus clarkii
Procambarus clarkii ( crayfish ) are organisms that thrive in the fresh water swamp parts of North America ; by and large in the parts of the south-central United States and northeasterly Mexico ( Rogers, 2000 ) . Crayfish are first-class theoretical account beings to carry on research on because of the location of the x-organ fistula at the base of the eyestalks. The crustaceous hyperglycemic endocrine ( cHH ) is a peptide that is produced and stored in the x-organs ( Fanjul-Moles, 2005 ) . This country besides houses neurosecretory cells that release the cHH. These cells cause the hepatopancreas to let go of more glucose into the hemolymph ( Sullivan, 2009 ) . For the intent of this survey they are first-class beings to experiment with due to the fact that the x-organs can be removed easy in order to see the effects with and without the hyperglycemic endocrine when they are induced with emphasis. Any endocrine that that raises blood glucose concentration is referred to as a hyperglycemic endocrine ( Saladin, 2010 ) . In decapod crustaceans, hyperglycaemia as a response to assorted sorts of emphasis has been observed. The crustaceous hyperglycemic endocrine is the regulator of the hemolymph glucose concentration in the spiny lobster when it is released from its storage installation in the x-organ composite. The cHH is a conducive factor for keeping the homeostatic belongingss to guarantee endurance of the crustacean. ( Chang, 2005 ) .
The intent for carry oning this experiment was to demo the correlativity between the presence of the hyperglycemic endocrine and the sum of hemolymph glucose concentration produced in spiny lobster. This survey involved the application of emphasis to find how the hyperglycemic endocrine regulates the sum of hemolymph glucose produced in a crayfish with and without eyestalks. Spiny lobster from which the eyestalks have been removed lack x-organs and sinus secretory organs and so they will non be able to bring forth or let go of the hyperglycemic endocrine ( Sullivan, 2009 ) . The working hypothesis of this experiment stated Procambarus clarkii with integral x-organs exhibit higher hemolymph glucose degrees so Procambarus clarkii without x-organs under emphasis conditions. The corresponding void hypothesis stated that there would be no difference between the experimental and control groups of Procambarus clarkii under emphasis conditions.
The undermentioned methods were modified from the Laborartoy Manual for Intorduction to Physiology ( Sullivan, 2009 ) . Five trial tubings were obtained and each one was filled with 0.1mL of crayfish Ringer ‘s and 3.0mL of the combined enzyme-color reagent solution. ( This solution included glucose oxidase, peroxidase, and 3-3 ‘ dimethoxybenzidine ) . The control trial tubing contained 0.1mL glucose criterion ( with a concentration of 5mg/100mL ) in add-on to the old four trial tubings. Then, to a cuvette 800 – 1,000AµL of crayfish Ringer ‘s solution were added. Two Procambarus clarkii ( crayfish ) were retrieved ; one with eyestalks and one without the eyestalks ( removed prior to lab ) . Approximately 0.1mL of hemolyph glucose was obtained from each of the spiny lobster at the base of the last walking leg utilizing a 1cc ( three-dimensional centimetre ) syringe. The gathered hemolymph was instantly placed into the designated trial tubing and was incubated for about 30 proceedingss at 37EsC. Following, while waiting for the trial tubing to incubate, about 0.1mL of spiny lobster of Crayfish toller ‘s was injected into the spiny lobster. Once injected, the spiny lobster were given a 15 infinitesimal relaxation period. After incubation was complete, the cuvette incorporating crayfish Ringer ‘s was placed in the Spectrophotometer – 20 from Bausch and Lomb to zero the machine. Approximately 800 – 1,000AµL of the incubated solutions and the incubated control were distributed into cuvettes and the soaking up was measured utilizing a Spectrophotometer – 20 set 450nm wavelength. Note that after every soaking up reading the Spectrophotometer – 20 was re-zeroed utilizing the crayfish Ringer ‘s space.
Next, the two spiny lobsters were placed in separate containers with about 500mL of 0.1 % trichloromethane ( nerve-racking environment ) for the same sum of clip, which was about 20 seconds. They were so placed back into clean H2O and were allowed to rest for 15 proceedingss. Using the method antecedently mentioned, 0.1mL of hemolymph was obtained from the “ stressed ” spiny lobster. Immediately after, these samples were so placed into the appropriate trial tubings and incubated for about 30 proceedingss at 37EsC. Once incubation was finished 800 – 1,000AµL were placed into cuvettes and the soaking up was determined utilizing the same technique already mentioned. All supplies used in this experiment were provided by the Carolina Biological Supply Company.
Table 1 shows the relationship between the hemolymph glucose concentration and the presence or absence of eyestalks ( x-organs ) before and after emphasis. The Procambarus clarkii ( crayfish ) with eyestalks ( x-organs ) exhibited an addition of hemolymph glucose concentration after emphasis. The spiny lobster without eyestalks ( without x-organs ) did non exhibit any discernible form of hemolymph glucose concentration.
Based on the information, the working hypothesis is failed to be rejected due to the fact that Procamburas clarkii ( crayfish ) without x-organs did non exhibit higher hemolymph glucose concentrations than crayfish that contain x-organs. The ground for this failed rejection was due to the fact that the consequences were important, as shown in Figure 1. It is apparent that the presence of the x-organ composite and the release of the crustaceous hyperglycemic endocrine increased the sum of glucose in the hemolymph after emphasis was induced. To farther support this decision, the spiny lobster without the x-organ composite did non bring forth an discernible form to demo that hemolymph glucose concentration was increased after emphasis was applied.
The crustaceous hyperglycemic endocrine ( cHH ) is really of import in keeping homeostasis in the spiny lobster ; therefore it is besides a factor in how the carnal behaves and alterations in anatomy due to the absence of this endocrine. The cHH is a subscriber to the endocrine household, including the molt-inhibiting endocrine ( MIH ) and the gonad-inhibiting endocrine ( GIH ) , that regulate of import physiological procedures, such as growing, reproduction and moult. ( Mettulio et al. , 2004 ) . This supports the observations made when the lab groups were taking their spiny lobster. The animate beings that had their eyestalks removed were a different colour and some were losing limbs. Since the cHH is besides a lending factor to the ordinance of growing and moult, it appears logical that the spiny lobster would be affected physically every bit good as chemically if this endocrine would non be present in the organic structure. The induced emphasis that was put upon the animate being without its x-organ complex and cHH caused the spiny lobster ‘s homeostasis to non work decently and produced the terminal consequence of sheding issues and glucose concentration issues.
A survey conducted by a Chinese scientist, Chi-Ying Lee and his associates, was really similar to the experiment conducted in category. Similarly they were researching the effects of the cHH, nevertheless in a different mode. They were researching how the cHH was involved in 5-hydroxytryptamine ( 5-HT ) induced hyperglycaemia. They discovered that 5-HT enhanced the release of the cHH which in bend elicits hyperglycemic responses. Another determination from the paper concluded that this response is non possible when the eyestalks are inhibited. ( Lee, et al. , 2001 ) . These scientists may hold obtained different consequences, but it reinforces that when the x-organ composite is present the hemolymph glucose concentration additions when the animate being is introduced to stimulations and when it is non present or inhibited, hyperglycemic responses are non achieved.
The informations obtained for the spiny lobster without eyestalks was skewed and could hold been this manner for a figure of grounds. The solutions could hold been made falsely or non incubated for the appropriate sum of clip. Another possible issue is the extraction of hemolymph from the spiny lobster. The sum could hold been less than required and hence could hold caused the spectrophotometer to hold registered falsely. A ground for this confusion could hold originated in the lab directions themselves. The country affecting the creative activity of the solutions to be tested was highly ill-defined ; to antagonize this issue the lab could be evaluated and rewritten to guarantee that lucidity is present in all facets of the lab. To turn to the issue of pull outing excessively small hemolymph from the spiny lobster ; a tutorial earlier lab to let pattern would be really good and would make comfort for the pupils executing the undertaking.
The on the job hypothesis for this experiment was non clearly stated and did non affect all the necessary information to make a valid decision. This is because one should non hold compared crayfish with eyestalks to those without eyestalks under emphasis. The comparing should hold been between crayfish with eyestalks before and after emphasis, and so compare the spiny lobster without eyestalks before and after emphasis. When one compares this it is clear that those crayfish with eyestalks release the cHH under emphasis as seen by the higher Numberss in Table 1. To account for this alteration the hypothesis should hold been written to include all of the information listed supra ; this would guarantee a complete hypothesis and solid foundation to construct consequences upon.
The crustaceous hyperglycemic endocrine is important in crayfish and all crustaceans for that affair, to guarantee homeostasis of organic structure maps and the physical facet of the organic structure itself. Without the x-organ composite the cHH is non present and the animate being can non react decently to emphasize ( stimulation ) that can do possible injury and possible decease. This survey concludes that spiny lobster with integral x-organs can antagonize the emphasis placed upon it by raising the hemolymph glucose concentration to keep homeostasis to guarantee endurance, while crayfish that contain no x-organs can non non secrete cHH and antagonize the effects of stimulation.
- Fanjul-Moles, M. 2005. Biochemical and functional facets of crustaceous hyperglycemic endocrine in decapod crustaceans ( On-line ) 142 ( 3 ) : 390-400. hypertext transfer protocol: //www.sciencedirect.com/science? _ob=ArticleURL & A ; _udi=B6W89-4HYD9MT- 1 & A ; _user=925033 & A ; _rdoc=1 & A ; _fmt= & A ; _orig=search & A ; _sort=d & A ; _docanchor= & A ; view=c & A ; _ searchStrId=1063538796 & A ; _rerunOrigin=google & A ; _acct=C000048221 & A ; _version=1 & A ; _url Version =0 & A ; _userid=925033 & A ; md5=f0870e41f8f2d91cd5a42630b7bcfc72. Accessed 24 October, 2009.
- Lee, C. P. Yang, H. Zou. 2001. Serotonergic ordinance of crustaceous hyperglycemic endocrine secernment in the spiny lobster, Procamburas clarkii ( On-line ) . hypertext transfer protocol: //www.jstor.org/pss/30158715. Accessed 25 October, 2009.
- Mettulio, R. , P. Edomi, E.A. Ferrero, S. Lorenzon, P.G. Giulianini. 2004. The crustaceous hyperglycemic endocrine precursors a and B of the Norway lobster differ in the preprohormone but non in the mature peptide. Peptides ( On-line ) 25 ( 11 ) . hypertext transfer protocol: //www.ncbi.nlm.nih.gov/pubmed/15501521. Accessed October 25, 2009.
- Rogers, J. 2000. Procambarus clarkii ( On-line ) , Animal Diversity Web. at hypertext transfer protocol: //animaldiversity.ummz.umich.edu/site/accounts /information/Procambarus_clarkii.html. Accessed October 25, 2009
- Saladin, K.S. , 2010. Anatomy and Physiology: The Unity of Form and Function. 5th erectile dysfunction. McGraw-Hill. New York, NY.
- Sullivan, J.D. 2009. Laboratory Manual for Introduction to Physiology.