Related Experiment Video
Updated: Jul 2, 2026
07:25
Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria
Published on: July 20, 2017
Does within-population variation in fish egg size reflect maternal influences on optimal values?
1Norwegian Institute for Nature Research, Tungasletta 2, N-7485 Trondheim, Norway.
The American Naturalist
|August 19, 2008
Summary
Fish egg size variation is adaptive, influenced by maternal effects and offspring environment. Demersal eggs show greater variation than pelagic eggs, suggesting selection primarily occurs posthatching.
Area of Science:
- Evolutionary Biology
- Ecology
- Ichthyology
Background:
- Maternal phenotype and offspring environment correlations predict adaptive variation in egg size.
- Previous models suggest adaptive egg size variation within populations.
Purpose of the Study:
- To conduct a comparative test of models predicting adaptive variation in fish egg size.
- To investigate the influence of maternal effects and offspring environment on fish egg size variation.
Main Methods:
- Comparative analysis of published fish egg size data.
- Statistical examination of intrapopulation variation in egg size across different fish groups.
- Analysis of egg and larval distribution patterns (demersal vs. pelagic).
Main Results:
- Intrapopulation variation in egg size was significantly higher in fish with demersal eggs and larvae (CV = 6.5%) compared to those with pelagic eggs (CV = 3.6%).
- This pattern held across taxonomic levels and habitats, independent of mean egg size.
- Fish with demersal eggs and pelagic larvae showed intermediate variation (CV = 3.8%), suggesting posthatching selection is a key driver.
Conclusions:
- Patterns of within-population egg size variation in fish reflect adaptive processes.
- Maternal effects on the egg size-fitness relationship are crucial and may explain deviations from single-optima models.
- Selection favoring egg size variation appears more intense posthatching than prehatching.
Related Concept Videos
01:11Testing a Claim about Mean: Known Population SD
A complete procedure of testing the hypothesis about a population mean is explained here.
Estimating a population mean requires the samples to be distributed normally. The data should be collected from the randomly selected samples having no sampling bias. The sample size needed to be higher than 30, and most importantly, the population standard deviation should be already known.
In most realistic situations, the population standard deviation is often unknown, but in rare circumstances, when it...
Estimating a population mean requires the samples to be distributed normally. The data should be collected from the randomly selected samples having no sampling bias. The sample size needed to be higher than 30, and most importantly, the population standard deviation should be already known.
In most realistic situations, the population standard deviation is often unknown, but in rare circumstances, when it...
02:27Background and Environment Affect Phenotype
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
01:24Testing a Claim about Population Proportion
A complete procedure for testing a claim about a population proportion is provided here.
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
00:55Parental Care
Many animals exhibit parental care behavior, including feeding, grooming, and protecting young offspring. Parental care is universal in mammals and birds, which often have young that are born relatively helpless. Several species of insects and fish, as well as some amphibians, also care for their young.
01:06Natural Selection and Mating Preferences
The principle of natural selection posits that organisms better adapted to their environment are more likely to survive and reproduce. This principle is closely intertwined with mating preferences, a key aspect of sexual selection, which evolutionary psychologists believe is driven by instincts to propagate one's genes. Such instincts significantly influence mating behaviors and preferences between genders.
Females, due to their biological roles in conception, pregnancy, and nursing, inherently...
Females, due to their biological roles in conception, pregnancy, and nursing, inherently...
01:06Fixed Action Patterns
A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs.