Search results
Results from the WOW.Com Content Network
Aristotle (ca. 340 B.C.) may have been the first scientist to speculate on the use of hard parts of fishes to determine age, stating in Historica Animalium that “the age of a scaly fish may be told by the size and hardness of its scales.” [4] However, it was not until the development of the microscope that more detailed studies were performed on the structure of scales. [5]
Fish stocks indicators, which is normalized as a 0–100 proximity-to-target score, with 100 representing "at target" and 0 being furthest from the target. Stock assessments provide fisheries managers with the information that is used in the regulation of a fish stock. Biological and fisheries data are collected in a stock assessment.
Fish stocks are subpopulations of a particular species of fish, for which intrinsic parameters (growth, recruitment, mortality and fishing mortality) are traditionally regarded as the significant factors determining the stock's population dynamics, while extrinsic factors (immigration and emigration) are traditionally ignored. Stocks fished ...
Fish with these high growth rates (and their progeny) sometimes develop a morphological abnormality similar to acromegaly in humans, exhibiting an enlarged head relative to the body and a bulging operculum. This becomes progressively worse as the fish ages.
The growth curve is used to model mean length from age in animals. [1] The function is commonly applied in ecology to model fish growth [2] and in paleontology to model sclerochronological parameters of shell growth. [3] The model can be written as the following: = ( (()))
Broodstock managers can use or select for traits such as fast growth rates or disease resistance over generations to produce more desirable fish. [15] This ability for genetic improvement of stocks is more efficient and produces higher value stock. Broodstocks also enable you to selectively plan and control all matings.
The individual growth model, published by von Bertalanffy in 1934, can be used to model the rate at which fish grow. It exists in a number of versions, but in its simplest form it is expressed as a differential equation of length ( L ) over time ( t ): L ′ ( t ) = r B ( L ∞ − L ( t ) ) {\displaystyle L'(t)=r_{B}\left(L_{\infty }-L(t ...
Fish embryos go through a process called mid-blastula transition which is observed around the tenth cell division in some fish species. Once zygotic gene transcription starts, slow cell division begins and cell movements are observable. [4] During this time three cell populations become distinguished. The first population is the yolk syncytial ...