Communities and Biomes

In this lab you will be exploring a community and biome by maintaining a reef tank, a form of marine biome.  A reef tank, or reef aquarium, is an aquarium that contains fish, live corals and other invertebrates associated with coral reefs.

24. Go to:  http://www.mhhe.com/biosci/genbio/virtual_labs/BL_24/BL_24.html
25. Read through lab carefully.
26. Make sure to read through reef tank and fish guides (on top of tank).
27. As you monitor the reef tank each “week”, fill in the following table.
28. After you finish monitoring week 12, answer the following questions.

	# of fish	# of invertebrates	Ammonia	Nitrate	Nitrite	pH	S.G	Temp
Week 1	0	0	0.00	0.00	0.00	8.1	1.022	78
Week 2	4	0	0.00	0.00	0.00	8.1	1.022	78
Week 3	4	0	0.02	0.00	0.00	8.1	1.023	79
Week 4	4	0	0.04	0.00	0.01	8.2	1.023	78
Week 5	4	0	0.00	0.00	0.05	8.2	1.024	78
Week 6	4	0	0.00	0.10	0.02	8.1	1.022	79
Week 7	4	0	0.00	0.20	0.00	8.1	1.023	78
Week 8	9	2	0.00	0.20	0.00	8.3	1.023	78
Week 9	9	2	0.01	0.20	0.00	8	1.024	78
Week 10	9	2	0.00	0.20	0.01	8.4	1.022	79
Week 11	20	7	0.00	0.20	0.00	8.2	1.023	78
Week 12	20	7	0.02	0.20	0.01	8.2	1.023	78

1. List the fish and invertebrates you selected after the nitrogen cycling process.

      After the nitrogen cycling process, I added four Scooter Blennies, one Yellow-Tailed Blue Damsel, and two Scarlet Cleaner Shrimps. In Week 11, I added six Yellow Tangs, four Maroon Clownfish, one Yellow-Tailed Blue Damsel, two Rose Anemones, two Scarlet Hermit Crab, and one Scarlet Cleaner Shrimp.

2. What changes did you make to your reef tank during the 12 weeks and why did you make them?

      In Weeks 5 and 9, I added water to normalize the specific gravity in the water tank. In Week 10, a buffer solution was also added to the water tank in order to lower the pH of the water which exceeded the accepted pH for a water tank. In the selection of fish for the reef, I chose fishes that are easy to manage (Scooter Blennies), undestructive and contributive to the environment inside the water tank (Scarlet Cleaner Shrimp, Yellow-Tailed Blue Damsel, Maroon Clownfish, Rose Anemones, and Scarlet Hermit Crab), and well-built to undergo the cycling (Yellow-Tailed Blue Damsel).

3. What problems, if any, did you have with any of the fish or invertebrates in the reef tank?

      There were no problems encountered with any of the fish or the invertebrates in the reef tank since the choices of fish and invertebrates were carefully selected, based on the Reef Tank Guide and Fish Guide to meet the requirements of the nitrogen cycle, the limits in the size of the fish after the cycling process, and most importantly the relationship between the fishes and invertebrates.

4. Describe the final population of the reef tank.

      The final population in the reef tank was composed of six Yellow-Tailed Blue Damsel and four Scooter Blennies since both species are harmless, easy to manage, and small in size, four Maroon Clownfish with two Rose Anemones since Clownfishes live cooperatively with other fishes with the same size, such as the Yellow-Tailed Blue Damsel and because they survive through the consumption of Rose Anemones, six Yellow Tangs since the water tank is large enough to accommodate them, and two Scarlet Hermit Crabs, three Scarlet Cleaner Shrimps, and two Margarita Snails in order to manage cleaning parasites, dead cells, and algae.

5. Compare the initial and final populations. What changes did you make to make to keep the fish and invertebrates alive?

      The initial population, (4 fishes) is comparatively smaller than the final populations (20 fishes and seven invertebrates). I made safe choices in selecting the fishes since they are not destructive to the physical environment and are not harmful to other fishes or invertebrates, unlike the Sharp-Nosed Puffer Fish. In addition, I also checked the Specific Gravity and pH levels every week in order to ensure that the conditions are normal. I added water to normalize the Specific Gravity for two weeks, and a buffer solution in one week to also normalize the pH level inside the water tank.

6. Study the data you collected. Describe the occurrences of ammonia, nitrite, and nitrate in your tank.

      The occurrences of ammonia, nitrate, and nitrite inside the tank change at infrequent intervals. The amount of the ammonia, nitrate, and nitrite inside the tank coincides with the nitrogen cycle, such that the first substance that exhibited change was the ammonia (0.00 to 0.02) which signals the start of the nitrogen cycle. The natural conversion of ammonia to nitrite was signaled by the change in the amount of nitrite inside the tank, and the subsequent conversion of nitrite to nitrate was also signaled by the changes in the amount of nitrate according to the tests.

7. Study the data you collected. Why is the population in the reef tank stable?

            The population in the reef tank is stable because the Specific Gravity and pH levels were maintained throughout the twelve weeks by adding water and buffer solution as needed. In addition, the species contained inside the tank were chosen according to their features and characteristics to ensure that they will live harmoniously with each other.