AFI 20306: Feeding & Growth II Flashcards

Vocabulary flashcards covering feeding mechanics, growth models, and physiological adaptations in fish and bivalve aquaculture based on Henrice Jansen & Roel Maas's lecture notes.

Growth (Production Biology)

The increase in size of an individual in time.

Standard Length (SL)

The measurement from the end of the upper jaw or snout to the end of the hypural bone.

Total Length (TL)

The measurement from the end of the upper jaw or snout to the tip of the longest caudal lobe when pinched together.

Fork Length (FL)

The measurement from the end of the upper jaw or snout to the end of the middle caudal fin rays.

Hyperplasia

A biological mechanism of growth involving an increase in the number of muscle fibers.

Hypertrophy

A biological mechanism of growth involving an increase in the size of existing muscle fibers.

Allometric Relation Formula

$Y = aW^b$, where $Y$ is organ weight/volume, $W$ is body weight, $a$ is the initial fraction, and $b$ is the growth-coefficient.

Specific Growth Rate (SGR)

The growth expressed as a percentage of mean body weight per day: $SGR = \frac{\ln(W_t) - \ln(W_0)}{t} \times 100\%$.

Von Bertalanffy Growth Equation (VBGE)

A model describing the growth rate as the difference between anabolism and catabolism: $\frac{dW}{dt} = a_1W^b - a_2W^c$, where $b = 2/3$ and $c = 1$.

Metabolic Body Weight (Fish)

Body weight raised to the power of $0.80$ ($W^{0.80}$).

Metabolic Body Weight (Shellfish/Mytilus galloprovincialis)

Body weight raised to the power of $0.79$ ($W^{0.79}$).

Compensatory Growth

A higher growth rate than normal following a period of nutrient restriction, often achieving partial or full recovery of body weight.

Hyperphagia

An unsatisfied drive to consume food that often occurs during the recovery phase of compensatory growth.

Maintenance Ration ($R_m$)

The feed ration at which growth is zero ($G=0$).

Feed Conversion Ratio (FCR)

A measure of efficiency calculated as: $FCR = \frac{\text{Feed Intake}}{\text{Gain}}$.

EC50

The Effective Concentration of a factor (like temperature or ammonia) that results in a $50\%$ response intensity.

NOEC

The No-Observed Effect Concentration; the level at which a factor does not negatively affect growth.

Seston

Bivalve food source consisting of micro-algae (phytoplankton), zooplankton, bacteria, and organic particles mixed with inorganic particles.

TPM or SPM

Total or Suspended Particulate Material.

Clearance Rate (CR)

The amount (volume) of water filtered or swept clear of suspended particles per unit of time ($L/h$).

Retention Efficiency (RE)

The percentage of available particles trapped on the gills as water is filtered.

Selection Efficiency (SE)

The efficiency with which a bivalve ingests high-quality particles through the mouth versus rejecting them as pseudofaeces.

Pseudofaeces

Non-ingested material packed in mucus and rejected by bivalves before entering the gut; also known as "fake poo."

Absorption Efficiency (AE)

The fraction of ingested food taken up by the animal and made energetically available for growth, reproduction, and maintenance.

Scope for Growth (SFG)

A model describing production per time unit as a Net Energy Budget ($NEB$).

Net Energy Budget (NEB) Formula

$\text{Production} = \text{food uptake} - \text{egestion} - (\text{respiration} + \text{excretion})$.

Shell Composition (Bivalves)

$95\text{-}99\%$ Calcium Carbonate ($CaCO_3$) and $1\text{-}5\%$ organic material forming a 3D matrix.

Labial Palps

Bivalve organs responsible for pre-ingestive particle processing, selection of edible fractions, and production of pseudofaeces.

Plasticity (Bivalves)

The ability to change phenotypic traits (behavior, morphology, physiology) in response to environment; can be short-term reversible changes.

Adaptation (Bivalves)

Heritable, non-reversible genetic changes in a population due to natural selection that provide a survival advantage.

Filtration Rate

The amount of material filtered per hour, calculated as: $\text{Clearance Rate} \times \text{particle concentration}$ ($mg/h$).

Bivalve Gill-to-Palp Ratio

A morphological adaptation where gill size increases and palp size decreases in low seston Environments to maximize clearance.