18 Aquatic Species

Question 1

Main aquatic environments (3)

Answer 1

1. Salt/Marine
2. fresh water
3. brackish
   * very few fish that can more from one environment to another

Question 2

Fresh water

Answer 2

water with very little mineral content

Question 3

Brackish

Answer 3

water that we often find in tidal flows, estuaries, mangroves; where we see a variable salt content

Question 4

Fish that can adapt from salt to fresh and vv?

Answer 4

salmon, eel
- able to tolerate the changes as a life stage change (not able to do so on a frequent basis

bullshark
-abel to tolerate on a daily basis

Question 5

pelagic fish

Answer 5

stay in the upper few hundred metres of the deep ocean;

Question 6

oceanic fish

Answer 6

inhibit the middle parts of the deep oceans

Question 7

neritic fish

Answer 7

spend most of their lives on the continental shelves and tidal area (less than 200m deeps)

Question 8

benthic fish

Answer 8

live at the bottom of the oceans in deep water; most live their entire life without seeing daylight

Question 9

littoral fish

Answer 9

ones we see most commonly, up to onto the shoreline

Question 10

bathyal fish

Answer 10

ones that are associated with the seabed as we get to the edge of the continental shelf into deep water

Question 11

abyssal fish

Answer 11

associated with the very depths of the ocean

Question 12

hadal

Answer 12

inhabits the deepest part of the oceans; dont know much about them

Question 13

How dangerous are sharks?

Answer 13

not so; of 344 species only 35 known to attack man or have the ability to do so

Question 14

Aquarium elements (7)

Answer 14

1. stocking density
2. gaseous exchange
3. heating
4. lighting
5. filtration
6. enrichments
7. chemical compostion

Question 15

Stocking density

Answer 15

how many animals can we have in our environment; depends on the water environment
*** Important to note that the water has a capacity to maintain a certain number of fish (based on the surface area or volume of the tank). However, that capacity assumes that all parts of your tank are functioning at their peak efficiency, including the filters that remove waste material from the water.

Now these filters are living things, if we talk about biological filters. They get put into a tank and must grow and settle in before they reach their peak capacity. That is what we mean by “maturing” the tank - making sure all parts of the system are operating at their most efficient; it takes time to let all the organisms settle down together.

Question 16

Brackish and Fresh water: stocking density

Answer 16

related to the surface area of fish: 1cm fish per 30 cm SA

-need to maximize SA –> shallow tanks

Question 17

Marine water: stocking density

Answer 17

volume more important than SA: 1cm fish per 4l

-can have 3d and deep tanks

Question 18

Stocking density of cold water

Answer 18

Cold water generally has lower SD than tropical water

- holds more o2 but demand for o2 is greater in cold water

Question 19

Gaseous exchange

Answer 19

ensure SA:V ratio is as high as possible; SA is very important for gaseous exchange

Question 20

Heating and lighting

Answer 20

• need to accommodate to fish regular environmental temperature (cold/warm water fish)
• lighting generally whatever you want to make your tank look good

Question 21

Filtration (3)

Answer 21

1. physical (pump)
2. chemical (detox/purification)
3. biological

Question 22

importance of filtration

Answer 22

• fish will end up sitting in their own waste products

- filters also disturb the top layer of water and produces ripples (which increase SA); facilitates gaseous exchange

Question 23

Biological filtration

Answer 23

• relies on the fact that ammonia (main waste product) breaks down and follows the nitrogen cycle
• can do this by growing bacteria in the aquarium (will help breakdown waste products)
• need bacteria to mature as we set up the fish tank; need to be ready for the fish

Question 24

n2 cycle

Answer 24

1. organic nitrogen > ammonia (deamination; break down amino group)
2. ammonia > nitrite (nitrification; add o2 molecule)
3. nitrite > nitrate (nitrification)
4. nitrate> nitrogen (denitrification; remove o2)

Question 25

Why is n2 cycle so important?

Answer 25

ammonia is extremely toxic (bleach) so it needs to be broken down to less toxic products

Question 26

Chemical composition (3)

Answer 26

1. Hardness
2. Salinity
3. pH

Question 27

Hardness

Answer 27

measure of mineral content in FRESH water

- need to mimic the water in animals natural environment (soft/hard)

Question 28

Consequence of hard water?

Answer 28

• Has a lot of caco3 ( when boil in kettle, hardens around the heating element as limescale)
• difficult to get soap to lather bc of the caco3

Question 29

Salinity

Answer 29

measure of mineral content in MARINE environments (ppt, microsiemens)

Question 30

pH

Answer 30

can alter by putting in different substrates, wood, plants

-affects n2 cycle (nitrification optimal ph 9, stops at 5.5)

Question 31

Treating infections (fungi, bacteria, protozoa) (2)

Answer 31

1. treat whole tank

2. isolate fish