G.portentosa Lab Report

Biology lab report Metabolic Rate of Gromphadorhina portentosa (Madagascar Hissing Cockroach) in Controlled Environments
View more...
   EMBED

Share

  • Rating

  • Date

    December 1969
  • Size

    158KB
  • Views

    643
  • Categories

Preview only show first 6 pages with water mark for full document please download

Transcript

Metabolic Rate of Gromphadorhina portentosa (Madagascar Hissing Cockroach) in Controlled Environments Abstract This experiment was conducted in order to test the gas exchange or metabolism of the ectotherm; Gromphadorhina portentosa, commonly known as the Madagascar hissing cockroach. One (1) G.portentosa was set in a clear experimental container and observed for approximately ten (1 ) minutes at a room temperature of !"o#$ %ollowing this observation the apparatus containing G.portentosa was submerged in cold water to provide a cold environment for the first run$ Then it was submerged in warm water to imitate a hot environment$ The carbon dioxide level and the temperature of the apparatus were observed for approximately ten (1 ) minutes in five (&) minute increments for both runs$ 'nder normal conditions such as the natural environment of G.portestosa carbon dioxide (#O!) and oxygen (O!) exchange increases as temperature increases allowing for more free movement$ The metabolism experiment proposed that in hotter temperatures the cockroach showed more gas exchange of #O! and also displayed more movement$ Introduction Metabolism is the totality of an organism(s chemical reactions to maintain life$ ) metabolic pathway usually comprises several steps such as a series of chemical reactions cataly*ed by en*ymes$ Thus the reactants of one reaction are the products of the previous one$ This cycle occurs repeatedly yielding processes for cell growth+ reproduction+ response to environment+ survival mechanisms+ sustenance+ and maintenance of cell structure and integrity$ ,t is made up of two categoriescatabolism and anabolism$ #atabolism is the degradative pathway that breaks down complex organic molecules such as fats+ carbohydrates+ and proteins into simpler molecules such as pyruvate+ #o!+ and .!O causing an oxidation reaction that releases free energy$ )nabolism is the constructive pathway that consumes energy to build complex molecules from simpler ones+ such as the formation of glucose from two pyruvate molecules+ which are sometimes called biosynthetic pathways$ The Madagascar hissing cockroach is an ectothermic insect+ which means it regulates its body temperature by exchanging heat with its surroundings unlike endothermic insects that generate heat by internal metabolic pathways to maintain body temperature$ (#ampbell and /eece ! 0) G.portestosa(s natural environment is the tropical dry forest and tropical rainforest$ Their lifestyle includes the breaking down of decaying plant and animal matter and their usual diet includes rotting fruits and fungi$ They are categori*ed as herbivores$ They live in large colonies containing subsets of smaller colonies within the large colony$ One male will dominate and hold a territory with several females$ ,f another male enters+ it is pushed out of the territory by the dominate male$ %emales may come and go within these male dominated territories$ (%ull and .erreid 110") ,n the experimental examination of G.portestosa+ levels of #O! were tested at different temperatures of hot or cold environments$ ,t was predicted that+ with increased temperature metabolic exchange of #O! and O! would also increase thus allowing free movement of G.portentosa closely mimicking its natural environment$ This prediction was predicated by knowing a brief history and knowledge of the natural habitat of G.portestosa Methods Preparation G.portestosa used in the experiment was taken from a container where all the roaches were held and placed into a two liter clear container allowing for behavioral observations during incremental increasing and decreasing temperature changes$ ) 2ernier 3ab4uest instrument was used to analy*e the O! and #O! levels inside the apparatus by inserting probes through two holes on top of the apparatus yielding digital readings of O! and #O! levels at specified time intervals$ ,n this experiment the levels of #O! were of greater importance than the O! levels$ To evaluate a correlation between temperature and rate exchange a thermometer was placed inside the container to get the temperature readings at each time interval$ CO! Levels with Respect to Temperature in a Cold Environment The apparatus containing the O! and #O! probes and thermometer was placed on the table for a few minutes to get initial readings of #O! levels and temperature$ The initial temperature inside the container was !"o# and the initial level of #O! was $!!5 6$ 7ext+ we placed the apparatus into a tub of ice+ inducing a cold environment for G.portestosa$ This was our first run of the experiment$ The emission of gases were read as percentiles and recorded for ten (1 ) minutes with five (&) minute intervals$ The temperature was recorded at each time interval as well$ )ll data was recorded in lab notebooks for later usage$ %rom this data an average of O! and #O! levels was calculated$ CO! Levels with Respect to Temperature in a Hot Environment To prepare for run two (!)+ the ice was dumped out into a sink and moderately hot water was filled into the tub$ The apparatus was then placed on the table for a few minutes to obtain initial readings as done for run one (1)$ )fter obtaining initial readings+ the apparatus was placed into the tub of hot water and was observed for the next ten minutes as well$ To prevent possible damage to the probes a book was used to keep the apparatus in place and prevent it from floating and tipping over$ )s in run one (1) the percentage of #O! level was recorded every five minutes along with the temperature$ Movement of the roach was also observed and noted$ )ll data was recorded in lab notebooks for later usage$ %rom this data the average #O! and O! levels were calculated$ 8ata from both runs were transferred from lab notebooks and prepared in Microsoft 9xcel$ Results CO2Levels with Respect to Temperature in a Cold Environment The initial temperature of the container was !"o# and the initial #O! level $!!5 6$ 9very five minutes the analy*ed data showed that as temperature decreased+ levels of #O! increased$ Movement of G.portentosa was minimal during the initial readings and to about ten (1 ) minutes into the experiment$ Movement was observed approximately ten (1 ) minutes into the experiment after the container was slanted slightly$ :hen the apparatus was slanted an increase in #O! levels was observed$ Movement stopped around twelve (1!) minutes$ Movement of G.portentosa was pertinent in this experiment but was observed and recorded in this report$ ,n ;raph 1+ the relationship between temperature and #O! level is depicted to show the increase in #O! level as temperatures decreased$ Temperature © vs CO2 level (ppm) 0.25 0.2 0.15 0.1 0.05 0 0 5 Temperature (c) 10 Temperature © vs CO2 level (ppm) Graph 1. Relationship between temperature I degree Celsius and CO 2 (%) level in a cold environment. ,n Table 1+ the emission of #O! along with the temperature at each time interval is shown$ Table 1 #O! levels at various temperatures in a cold environment$ CO2 level (ppm) Time Ela!sed (mins) & 1 Tem!erature (oC) 1 0 < C"# $evel (%) $1&"! $1<>1 $11>< The calculated average change in #O! (6) level per degree #elsius of change in temperature was $ 11<&6$ These calculations were derived by taking the total change in the #O! percentage and dividing it by the total change in temperature$ CO! Levels with Respect to Temperature in a Hot Environment ,nitial temperature for this run was "!o# with initial readings of #O! level at $15"&6$ 9very five minutes the observed data showed that an increase in temperature was directly proportional to an increase in #O! levels$ Movement observed was very minimal during the time period between *ero ( ) and seven (<) minutes of the experiment however towards the end of the ten (1 ) minute period the cockroach was moving fast and freely about the apparatus$ =elow in Table !+ the emission of #O! gases are shown as well as the temperature for each five (&) minute interval$ Table # O! and #O! levels at various temperatures in moderately hot temperatures$ Time Ela!sed (mins) & 1 Tem!erature (oC) "! "> "! C"# $evel (%) $15"& $1"&> $1&&< ,n ;raph !+ the relationship between temperature and #O! (6) level is graphed to easily view the rise in #O! level as temperature in degree #elsius increased$ Temperature © vs. CO2 level (ppm) 0.17 0.165 CO2 level % (ppm) 0.16 0.155 0.15 0.145 0.14 41.5 Temperature © vs. CO2 level (ppm) 42 42.5 43 43.5 Tem perature (C) &ra!h ' /elationship between temperature in degree #elsius and #O! (6) level in a hot environment$ The calculated average change in #O! (6) level per degree #elsius of change in temperature was $ 1"06$ These calculations were derived by taking the total change in O! or the #O! percentage and dividing it by the total change in temperature$ (iscussion The stated hypothesis said+ the higher the temperature the more #O! is going to be exchanged and the roach will be freely moving because this closely mimics its natural environment$ )s a result+ the prediction was proven correct+ through observation and from the data collected$ ,n the hot environment+ O! and #O! levels increased as the temperature inside the apparatus increased$ ,n the cold environment+ O! and #O! levels decreased as temperature decreased$ )ll data collected from this experiment and presented in this report fail to re?ect the null hypothesis stating that that as temperature increases #O! levels increase allowing free movement of G.portentosa$ 8uring observation of G.portentosa when placed in a cold environment it was apparent that the insect did not acclimate well to the cold environment evidenced by minimal movement and gas exchange and a hissing noise heard while in the colder environment$ ,n the warmer environment G.portentosa acclimated very well as evidenced by observed increase in O! and #O! exchange+ increased movement and a lack of hissing$ )lthough the movement of the cockroach was not relevant to the metabolic rate or gas exchange+ G.portentosa showed more movement in the warmer environment$ )ll graphs and tables in this report give a visual relationship between levels of #O! at varying temperatures$ 9xperimental data and observation was compared to others in the laboratory+ and seemed to yield the same results; hotter temperatures corresponded to more O! and #O! gas exchange$ This correlation between gas exchange and temperature includes but is not limited to serving as an indicator of G.portentosa(s ability to acclimate to certain environments$ %or example O! enters the cockroach through tiny breathing tubes called tracheae to all of the body parts #O! is then released$ (=radley and #ontreras ! 1)$ The cockroach has the ability to press air through its spiracles to make a hissing noise as a sign of aggression+ hence the name of the cockroach$ ;as exchange increases when the cockroach is comfortable with the environmental conditions regardless if the conditions are in a laboratory setting or its natural environment (=lackburn and #hown ! 0)$ 8uring this experiment there were no ma?or complications$ .owever for future experiments results may be improved if the sample si*e were increased$ ,n addition to sample si*e the sub?ect should not only be observed at room temperature but should also be observed for a period of time after being aggravated+ inducing hissing$ )t this time gas exchange should be measured before the manipulating the temperature$ =y doing this it would be possible to show whether or not aggravation and temperature are dependant or independent of each other in relationship to gas exchange$ $iterature Cited )rticles=lackburn Tim M+ #hown @teven 3+ Marais 9lrike+ Terblanche Aohn @+ :hite #raig /$ ! 0$ @caling of gas exchange cycle fre4uency in insects$ =iol 3ett$ "(1)- 1!B5> p$ %ull /obert A+ .erreid ,, #lyde %$ 110"$ #ockroaches on a treadmill- )erobic running$ Aournal of ,nsect Chysiology$ > (&)->1&B" &$ The =ig Doo E,nternetF$ #! 1 $ Magnolia (TG); Ecited ! 1 March ! 1 F$ )vailable from- http-HHwww$thebig*oo$comH)nimalsHMadagascarI.issingI#ockroach$asp