Exam II

Fish 422 (Concepts in Aquaculture)

In class portion

November 8th, 2001

Please read all questions thoroughly and provide complete answers (feel free to use the back of the page if necessary). Good luck! (100 pts total)

  1. (2 pts) Catfish can break down starch in their diets better than coldwater species. What is the likely reason for this?
  1. (4 pts) Why does cryopreservation work for fish sperm but not eggs? How does cryopreservation work and why use it?
  1. (6 pts) List the four parameters that could be used to estimate carrying capacity and describe the primary factors that are important for each. Which are most often used?
  1. (6 pts) In Dr. Cloud’s lecture he talked about collection and storage of sperm for long and short periods of time. What is an important characteristic of fish sperm that must be taken into account when transporting or storing for a short period of time. How did he suggest transporting milt to maintain the highest level of viable sperm?
  1. (10 pts) In commercial rainbow trout production it is desirable to have all female lines. Why? Briefly explain 2 ways a mono-sex all female population can be obtained.
  1. (True or False) (2 pts) Daily energy requirements of fish increase throughout their life.
  1. (10 pts) Draw an energy budget for fish and explain the elements of distribution.
  1. (8 pts) Explain the concepts behind NATURES rearing of fish for supplementation purposes.
  1. (6 pts) Name 2 things that make the use of extruded feeds desirable over traditional pelleted diets.
  1. (6 pts) What are the 3 primary dietary components in feed? What is the significance of each?

  1. (25 pts) Explain the Feed Conversion Ratio (FCR). If fish on your facility appear healthy and are feeding well, but are exhibiting poor (high) FCRs, what are 3 possible reasons for this? Assume that all water quality parameters are within the “no-effect limit.
  1. (5 pts) In catfish culture programs, why are broodfish used that are typically less than 4.5kg?
  1. (10 pts) Explain the significance of phosphorus in fish diets. What are 3 ways (related to feeds) to reduce the amount of phosphorus in the effluent of a fish culture facility?


Exam II

Fish 422 (Concepts in Aquaculture)

Take home section

November 8th, 2001

Responses to all questions are due at the beginning of class on November 13th. Please provide answers and show any calculations on separate sheets of paper, preferably typed computer output. Required tables for calculations are found in Klontz’s “Concepts and Methods…” manual. Good luck! (100 pts total)

  1. (25 pts) Given the following information, determine the missing carrying capacity parameters. For OCAP calculations, use the SMR method of Klontz.

Species: RBT-shasta strain

Raceway A: inflow DO = 9.3 mg/l

Water temp.: 15oC

Flow rate: 10 lps

Available DO = DOin – (0.7 x DOin)

Raceway dimensions (10m x 1m x 0.3m)

  1. Available DO in pond (mg/h) ______
  2. Permissible biomass in pond (assuming you want 300g fish at “take out”)

Based on OCAP______

Based on DCAP______

  1. Permissible number of fish in pond (at “take out”)

Based on OCAP______

Based on DCAP______

Based on your calculations, which figure would you use to determine initial stocking densities? If you estimate that the fish will reach 300 g in 5 months (150 days), how many fish would you stock (assuming standard mortality rates) in this pond? Justify your answers.

  1. (15 pts) You are a RBT hatchery manager in Buhl, ID, and recently your fish have been swimming on the surface and you are losing approximately 30 fish/day in this pond. You notice that the rainbow trout exhibit saddle-like lesions around their dorsal fin. Knowing that this is typical of a Flavobacterium columnare infection, you immediately call your veterinarian. It is recommended that you feed your fish feed medicated with Terramycin at a dose of 3.0 g/100 lb/day for 10 days. Your medicated feed contains 8.0 g of Terramycin per kg of feed. In your pond, you have 11,500 kg of fish. How much medicated feed should you feed your trout over the 10 day period?
  1. (5 pts) What would you estimate the FCR to be for a diet fed containing 3079 kcal/kg of metabolizeable energy being fed to Pacific salmon (show all calculations)?
  1. (15 pts) If a raceway contains 5000 kg of fish on the start of a production cycle how much feed would be needed on day one if they were to be fed at 3.0 % body weight? Assuming logarithmic growth, calculate how much feed would be needed for this group of fish on the second day of the production cycle (1 day of growth)? Use the FCR you calculated for question #4 to determine the feed rate.

  1. (40 pts) Complete the following inventory data table (show all calculations).

Species: RBT-shasta Pond #: Raceway 01

Date of inventory 2/14/00

Date of previous inventory 2/1/00

Start End Change

Length (mm) data: Mean: 57.2 67.2 ______

Range: 30 42 ______

Median: 57 68 ______

Mid-range 56.5 70.5 ______

Daily increase (mm) _____

Weight (g) Data: Mean: 1.939 3.133 ______

Specific Growth Rate (%) _____

Condition Factor (K) ______

Headcount: 50,000 _____ 65

Biomass (kg) ______

Density Index (kg/m3/cm) ______

Flow Index (kg/lpm/cm) ______

Water inflow (lps) 10.2 11 ______

DO inflow (mg/l) 10.2 9.4 ______

DO outflow (mg/l) ______

(use SMR method)

Water temperature (C) 13 15 ______

Elevation (m) 1000 1000 na

Pond volume (total m3) 19

(rearing area m3) 17

95% replacement time (min) ______

Feed fed (assume 100% Dry matter) 51 kg (over 14 days)

FCR