Exercise 2 Where would a fish with a terminal mouth most often be feeding?

Exercise 3 What differences do you observe in the structure of the alimentary canals of the two species?

Exercise 4 How might the differences you have observed be related to diet?

Pelagic Lifestyle

• Body Structure: Often streamlined for efficient swimming (like fish, sharks, and dolphins) or with adaptations for floating (like jellyfish and plankton).

• Buoyancy Adaptations: Many pelagic organisms have structures to help maintain buoyancy, such as swim bladders in fish or gas-filled bladders in some algae.

• Feeding Adaptations: Pelagic species often feed on plankton or other small organisms, or they may be fast-swimming predators.

• Sensory Adaptations: Well-developed sensory systems for detecting food and avoiding predators in a three-dimensional, open-water environment.

• Mobility: High mobility to navigate and find food, often migrating over large distances.

• Body Color: Pelagic species often have silver, blue, or grey colors with a reflective quality, helping them camouflage in open water. These colors reflect light and make them less visible to predators or prey from certain angles.

  
  

Benthic Lifestyle

• Body Structure: Generally adapted to life on or near the substrate, with many benthic organisms being flatter (like flounder), having appendages for attaching to surfaces (like sea stars), or burrowing adaptations (like worms).

• Feeding Adaptations: Benthic organisms often feed by filtering detritus from the water, grazing on algae, or scavenging, although some are active predators.

• Protective Adaptations: Many benthic species have shells or exoskeletons for protection, given their proximity to the ocean floor where predation risks can be high.

• Reduced Buoyancy Needs: Benthic organisms don’t need structures for buoyancy; instead, they may be adapted to stay close to or on the substrate.

• Mobility: Lower mobility than pelagic organisms, with some being entirely sessile (e.g., corals, barnacles), while others are slow-moving (e.g., crabs, sea stars).

• Body Color: Many benthic species are brown, grey, green, or black to blend in with substrates like rocks or sand. For example, crabs and bottom-dwelling fish are often brown or grey, helping them match their surroundings.

  
  

Exercise 2:

Fish with a terminal mouth often be feeding in the water column or mid- water.

Exercise 3:

Ikan Kembung

• The size of intestine, stomach, liver is smaller than talapia fish

• From the gender analysis the fish is female

• There are two components in the reproductive part of this fish, namely the yellow gonads and the ovaries

Ikan Talapia

• The size of the intestine, stomach, liver is bigger than the puffer fish

• From the analysis of the gender of the fish Male

• There are two components in the reproductive part of this fish, namely the white gonads and the testicles

  
  

Exercise 4

Ikan Talapia

-Based on observation, the fish stomach is empty

Ikan kembung

-Based on observation, there is a brown colour in the state of half liquid

its indicate that those fish diet consist of plankton

 https://youtu.be/G2BKVhFgpVU

1.What are the disadvantages of using artemia as a food?

2.List four ingredients needed in culturing the artemia.

3.How much salt do we need to get 25 ppt of salinity?

4.Why we need a baking soda in culturing the artemia?

5.What is the suitable temperature for artemia culture?

6.How long does it take to harvest the artemia?

• High cost of production.

• Variable nutritional content.

• Limited availability.

• Risk of disease transmission.

• Dependency on specific hatching conditions.

• Inadequate for all life stages.

2.Ingredient for culturing artemia

• Salt (NaCl): To create a saline environment suitable for Artemia hatching and growth.

• Water: Clean, dechlorinated water to maintain optimal salinity and quality

• Aeration System: For providing oxygen and maintaining water circulation.

• Food Source: Microalgae, yeast, or commercial Artemia feeds for nutrition.

3.Salt for 25ppt

• To achieve a salinity of 25 parts per thousand (ppt), we need to dissolve 25 grams of salt in 1 liter of water. (10 liter of water = 25 grams x 10 ).

  
  

4.Baking Soda Function

• Artemia thrive in slightly alkaline conditions, typically in the pH range of 7.5 to 8.5. Adding baking soda helps buffer the water and ensures the pH remains in an optimal range for the shrimp's growth and development.

5. Suitable Temperature

• the suitable temperature for artemia culture is between 25°C to 30°C.

6. Time for harvesting artemia

• It typically takes 18 to 24 hours to hatch Artemia cysts under optimal conditions. After hatching, the nauplii can be harvested immediately for feeding. For growing Artemia to larger stages, 5 to 10 days, depending on the desired size and environmental conditions.

1.      what are the disadvantages of using artemia as food?

-        Nutritional deficiencies due to lack of sufficient levels of long-chain polyunsaturated fatty acids (LC-PUFA) that are crucial for growth and development

-        Short shelf life when Artemia hatched as it can be troublesome for aquaculture facilities with varying feeding schedules.

-        Artemia need saline water to thrive so it is unable to breed without adjustments in freshwater systems

-        High cost as the cyst of Artemia can be overpriced.

2.      List four ingredients needed in culturing the artemia.

-        Salt

-        Dechlorinated water

-        Artemia cysts(Brine shrimp eggs)

-        Aeration

3.      How much salt do we need to get 25 ppt of salinity?

-        25 grams of salt/litre of water

4.      Why do we need baking soda in culturing the artemia?

-        To stabilize the pH of the water

5.      What is the suitable temperature for artemia culture?

-        Between 25°C and 30°C

6.      How long does it take to harvest the artemia?

-        18 to 24 hours