How do you determine fish fecundity?

The fecundity is then F = nV/v where n = number of eggs in the subsample, V = volume to which the total number of eggs is made up and v = volume of the subsample. In practice, it is normally necessary to count more than one subsample from each fish to get a reliable estimate of the fecundity.

What is the importance of fecundity?

Fecundity measurements are of particular importance in animal biology and ecology since they are used for assessing population reproductive dynamics and energetics and for estimating their annual reproductive output and how it is linked to recruitment and population growth (Stearns 1992).

Why it is important to study fecundity of fish?

Knowledge of the fecundity of a species is an important factor in fish stock management. It is used to calculate the reproductive potential of a stock and the survival from egg to describe a fish which is spawning for the first time.

Which factors can really affect fecundity of fish?

Fecundity and egg production are affected by several factors, including environmental variations, food availability, breeding season duration, and spawning frequencies (Vazzoler, 1996).

How is fecundity measured?

Fecundity is measured by the number of offspring that are created successfully. In sexually reproducing organisms, two gametes must meet and the process of fertilization must occur.

What is fish relative fecundity?

Fecundity is generally defined as the egg laying capacity of a fish. … Relative fecundity is the number of eggs per unit body weight and the total (absolute) fecundity is the total number of eggs that are likely to be spawned in one spawning season.

Is fecundity hereditary?

Fecundity is a developmental and genetic trait that advances within a specific framework. Dependent on various factors, e.g. lifestyle, stress, emotional and reproductive health, willingness, availability of a potential mating partner, and preventive measures being taken.

Is fecundity declining explain?

Fecundity can increase or decrease in a population according to current conditions and certain social factors. … Indeed, it is considered impossible to cease reproduction based on social factors, and fecundity tends to rise after a brief decline.

What is the difference between fecundity and fertility?

Fertility is the number of children born to a woman, while fecundity is her physiological potential to bear children. Fertility is often used as measure of fitness, and fecundity is related to reproductive value.

How long are fish pregnant for?

As examples, the female swordtail and guppy will both give birth to anywhere from 20 to 100 live young after a gestation period of four to six weeks, and mollies will produce a brood of 20 to 60 live young after a gestation of six to 10 weeks.

How is GSI measured in fish?

Calculate Gonadosomatic Index (GSI = (gonad weight (g) / fish weight (g)) *100).

What is the spawning season?

shed into the water (spawning), where the eggs are fertilized. Most echinoderms spawn on an annual cycle, with the spawning period normally lasting one or two months during spring or summer; several species, however, are capable of spawning throughout the year.

What is the life cycle of fish?

The life cycle of marine fishes is comprised of four developmental stages: egg (or embryonic), larval (yolk-sac and non-yolk-sac), juvenile and adult. The eggs and larvae of marine fishes are called ichthyoplankton.

What are the three ways of estimation of fecundity?

There are several methods for the estimation of fecundity of fish. These are (a) Volumetric method, (b) Gravimetric method and (c) Von Vayer method (Lagler, 1956). Volumetric method and Von Vayer method have been found to be suitable for relatively large eggs.

What is breeding in fish?

MEANING OF FISH BREEDING. Fish breeding is the act of producing young ones from parent brood fish. This ensures species continuity and survival. In aquaculture, fish breeding is a very important activity ensuring availability of fingerlings for the stocking of ponds, pens, tanks and cages.

What does Fecundability mean?

Fecundability is defined as the probability of achieving a pregnancy within one menstrual cycle or the ability to achieve a live birth from one cycle’s exposure to the risk of pregnancy (ESHRE, 2001).

What animals have high fecundity?

Prey species like mice and rabbits have higher losses of offspring to predation. For these species, having high fecundity increases the likelihood that some of the offspring will survive to reproduce themselves.

What is fecundity rate?

In demography and biology, fecundity is the actual reproductive rate of an organism or population, measured by the number of gametes (eggs), seed set, or asexual propagules. … Fecundity can increase or decrease in a population according to current conditions and certain regulating factors.

How do you find the relative fecundity of a fish?

Relative fecundity was obtained by dividing absolute fecundity with total weight of fish.

What is ecological fecundity?

In ecology, ‘fecundity’ can be described simply as the. physiological maximum potential reproductive output of. an individual over its lifetime, and it is usually applied to. the female’s (rather than a male’s) output, although there. is no inherent reason why fecundity should be restricted.

What is absolute fecundity?

Definition of Term absolute fecundity (English) Total number of eggs in a female. (

How does fecundity affect fertility?

Literally, fecundity means the ability to produce live offspring, and fertility means the actual production of live offspring. So fecundity refers to the potential production, and fertility to actual production, of live offspring.

Is human fecundity declining?

Human fertility rates are declining all over the world (Fig. 1). In some Western countries the rates are far below the point at which the population can be main- tained at the current level (Lutz et al., 2003; World Bank, 2005).

What is a synonym for fecundity?

In this page you can discover 13 synonyms, antonyms, idiomatic expressions, and related words for fecundity, like: richness, rich, infertility, productivity, abundancy, fertility, fruitfulness, productiveness, prolificacy, prolificness and fruitlessness.

What is the difference between fecundity and fertility quizlet?

Fecundity is similar to fertility. it is the actual reproductive rate of an organism or population, measured in the number of gametes. … Fertility is the natural capability to produce offspring.

How do you use fecund in a sentence?

Fecund in a Sentence

  1. The computer programmer was a fecund person who could quickly identify and solve problems.
  2. Although Jim was fecund at work and always met his daily goals, he rarely left his favorite chair at home.
  3. The airline is looking for fecund individuals who can complete many tasks in a short period of time.