The condition factor was calculated by the formula (Pauly, 1983): Condition Factor (K) = 100W⁄ L3 where W is weight (g) and L is total length (cm). This study analyzed the length-weight relationship of the two major fish species collected from Wudil River.
What is fish index?
Fish Is Food – The FAO’s Fish Price Index
The fish price index (FPI) relies on trade statistics because seafood is heavily traded internationally, exposing non-traded seafood to price competition from imports and exports.
What is ponderal index in fish?
Condition factor or Ponderal Index
• The condition factor or Ponderal index, or co- efficient. of correlation expresses the condition of a fish, such as the degree of well being, relative robustness, plumpness or fatness in numerical terms. The condition factor used to determined from length and weight of the fish.
What is the use of condition factor?
The condition factor (K) of a fish reflects physical and biological circumstances and fluctuations by interaction among feeding conditions, parasitic infections and physiological factors (Le Cren 1951). This also indicates the changes in food reserves and therefore an indicator of the general fish condition.
How do you find the relative condition factor of a fish?
The relative condition factor (Kn=w/W) is the ratio of observed weight (w) of a fish at a given length to the expected weight (w) of a fish of the same length as calculated from the length weight regression (Le Cren, 1951), has been calculated separately for males and females of D.
How do you measure fish health?
The condition index in fish is a way to measure the overall health of a fish by comparing its weight with the typical weight of other fish of the same kind and of the same length. The condition index is its actual weight divided by its expected weight, times 100%.
What is index abundance?
An index of abundance is a relative measure of the size of a population or sub-unit of the population, such as a year class. It is usually measured as number (or weight) of fish caught per standard unit of fishing effort.
Why is length weight relationship in fish important?
Length-weight relationships (LWRs) and relative condition factor are of great importance in fishery assessment studies since it provide information about the growth of the fish, its general wellbeing, and fitness in a marine habitat.
How do you find the abundance index?
You can calculate species relative abundance byTotal Number of Individual species (Isi) divided by Total Number of Species Population ( ∑ Nsi) multiply by one hundred (100).
How is growth and age determined in fish?
Scales from individual fish are placed in an envelope like those used by coin collectors. … Aging fish is similar to aging a tree by counting the number of growth rings. However, the age of the fish is determined by counting the number of wide growth rings called annuli.
What is condition factor K?
The Condition Factor K allows the Department to compare quantitatively the condition of individual fish within a population, individual fish from different populations, and two or more populations from different localities. K may also be used as an index of the productivity of a water.
How do you calculate fish K factor?
- Factor (K) =
- 100 * g /
- cm ^3.
What is isometric growth in fish?
Widely accepted concept is that if the exponent value is 3, the fish grows isometrically, if it is greater or less than 3 fish grows allometrically (Tesch, 1968).
How is Fulton’s condition factor calculated?
- K = 100 * W L 3 . (3)
- V = f(L)L3 (4)
- W = ρ*k*H*D*L = ρ*k*k2L*k3L*L. (5)
- W = S*k3*L3 = 100*K*L3 (6)
What is length weight relationship model?
An accurate length-weight relationship equation allows for the conversion of growth-in-length to growth-in-weight in stock assessment models, as well as the estimation of biomass from the length frequency distribution, condition (Petrakis and Stergiou, 1995.
What is the need of conducting stock assessment in fisheries?
Stock Assessments Provide Scientific Advice For Sound Fisheries Management. Stock assessments are one important piece of a dynamic cycle of management aimed at preserving our ocean resources. They provide scientific advice to decision-makers on the current health and future trends of a fish stock and its fishery.
How is condition factor calculated?
Furthermore, fish speceices were identified and then fish individuals were measured and then it was calculated a condition factor (CF) using following formula: CF= (W/L3) x l00 W – weight of fish body in grams; L – length of fish in centimeters.
Why is it important to monitor the health of the fish populations?
Fish populations are monitored because they are key components of the aquatic ecosystem and important ecological indicators that integrate natural and development-related changes over time. Fish are also a highly-valued subsistence and recreational resource in the region.
What is Shannon index of diversity?
The Shannon diversity index (a.k.a. the Shannon–Wiener diversity index) is a popular metric used in ecology. … The index takes into account the number of species living in a habitat (richness) and their relative abundance (evenness).
What is a population index ecology?
These are indices that are used to summarize population dynamics and characteristics in one number. The life table uses the current age-specific death rates and applies them to a hypothetical population of 100,000, “aging” them through time until all the hypothetical members die. …
What is population abundance?
Population size is the actual number of individuals in a population. Population density is a measurement of population size per unit area, i.e., population size divided by total land area. Abundance refers to the relative representation of a species in a particular ecosystem.
How do you calculate weight based on length?
To calculate dimensional (DIM) weight, multiply the length, width, and height of a package, using the longest point on each side. Then, divide the cubic size of the package in inches by the DIM divisor to calculate the dimensional weight in pounds.
What is positive Allometric growth?
Positive allometric growth implies the fish becomes. relatively stouter or deeper-bodied as it increases in length. and is indicated by a β > 3.0. The coefficient α, it should. Table 1.
How is Shannon index calculated?
Take the natural logarithm of each proportion (lnp) and then multiply the proportion and the ln of the proportion (p*lnp). Add these values together, take the negative value of it (to make it positive) and you will have your Shannon Weiner index score (H’).
How do you calculate diversity index?
- Add the individual species populations to get N .
- Determine N × (N – 1) .
- Work out n × (n – 1) for each species, where n is the number of individuals in each species.
- Sum all the values in step 3.
- Divide the sum obtained in step 4 by the value obtained in step 2.
How is biodiversity index calculated?
One way to calculate a simple biodiversity index is by dividing the species richness by the species evenness. Take it outside! Try this methodology in your backyard or a local park to measure the biodiversity of organisms.
How do you count fish years?
Aging fish is similar to aging a tree by counting the number of growth rings. However, the age of the fish is determined by counting the number of wide growth rings called annuli. In our example, the bluegill is 4 years old.
How otolith is used in fish age determination?
Biologists estimate fish age by counting these opaque zones, called annuli, just as one would count rings on a tree to determine its age. For each species to which it is applied, the method of estimating age by counting annuli must be validated to prove that one whole annulus is equal to one year of growth.
What is the growth rate of fish?
growth-rate occurs between 69th and 73rd days, since 100 embryos form 1*7 gm. of new tissue during this period, and at that time they weigh approximately 9-5 gm.
What is isometric and allometric?
The key difference between allometric and isometric growth is that allometric growth refers to the unequal growth rate in different parts of the body in comparison to the growth rate of the body as a whole while isometric growth refers to the equal growth rate of body parts in comparison to the growth rate of the body …
What is the difference between isometric and allometric?
Allometric growth is when an organism grows and the proportions of its body parts are different. The word ‘allometric’ means different measure. … Isometric growth is the exact opposite of allometric growth. ‘Isometric’ comes from the Greek for same measure.
What is intermittent growth?
Intermittent growth is a common feature of growth cone motility, in both the optic chiasm ( A ), a decision region, and the optic tract ( B ), a straight path. … Frames were taken in the chiasm every 15 min, and in the tract, every 20 min. Asterisk indicates a break in the sequence of the frames displayed.