What is normal liver somatic index?
The size of the liver increases with depth of occurrence (Fig. 7.6) such that the hepatosomatic index (HSI) reaches a maximum at about 2000 meters and a size of 20–25% of body weight. The lipid content of the liver also increases with depth, but levels off at about 2000 meters and a content of 60–90% (Fig.
How do you calculate Hepatosomatic index?
Hepato-somatic index (HSI) was calculated as : HSI=(LW/W)•10 0 where LW and W are liver weight and somatic weight (g), respectively . Head on gutted weight and head off gutted weight were also measured (± 1 g) to estimate muscle weight and to allow calculations of somatic weight from gutted weight .
What is Gonadosomatic index in fish?
The gonadosomatic index (GSI) is the ratio of fish gonad weight to body weight. The GSI is particularly helpful in identifying days and seasons of spawning, as the ovaries of gravid females swiftly increase in size just prior to spawning.
What is Hepatosomatic index used for?
Hepatosomatic Index (HSI) is defined as the ratio of liver weight to total body weight and used as a measure of the energy reserves of an animal, especially in fish. …
What is Gonadosomatic index used for?
The gonadosomatic index (GSI), measuring the ratio between gonad weight and body weight (either total or gutted weight), is frequently used to compare reproductive condition across individuals or across different groups of individuals (e.g., DeVlaming et al., 1982).
Why Gonadosomatic index is important?
Gonadosomatic index (GSI) and fecundity are one of the most essential parameters in studying the reproductive biology of every fish. GSI is a parameter that is used to study the spawning biology of the fish. It also assesses the level of ripeness of the ovary [7].
What is 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.
What organs does a fish have?
The major internal organs common to most fish species. (1) Liver, (2) stomach, (3) intestine, (4) heart, (5) swim bladder, (6) kidney, (7) testicle, (8) ureter, (9) efferent duct, (10) urinary bladder, and (11) gills.
Why we need to study the gonadal maturity of fishes?
The age and size at sexual maturity may be important in assessing the optimum age of first capture of a species and the time and place of spawning can be used to plan fishing tactics because many species of fish are easiest to catch when they congregate to spawn.
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.
What is length weight relationship?
The log transformation formula of Le Cren was used to establish LWRs (Le Cren, 1951). The length-weight equation W = a Lb was used to estimate the relationship between the weight (g) of the fish and its total length (cm).
What is the formula of condition factor?
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.
What are the 7 physical structure of fish?
How do you calculate Gonadosomatic index of fish?
GSI was computed as the ratio between gonad weight (G) and gutted weight (W) in each individual sampled as follows: GSI=GW.
What is Fulton’s condition index?
The Fulton formula It’s possible to estimate the weight of a trout based on what’s known as the K-factor or the condition – you could call it the BMI or health index of the fish. The factor is calculated using the Fulton formula. Fulton suggested this in the early 1900’s: K = 100 × weight/length^3.
What is fish condition factor?
What is Fulton’s condition factor?
From this, Fulton’s body condition factor K (Fulton, 1904) was estimated as(1) K = 100 , 000 × W L 3 , where W is the weight (g) and L the FL (mm). K factor is a non-lethal morphometric index estimate of body condition, which is determined by measuring the weight and length of individual fish.