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A F Alimov

Publications and source records attributed to A F Alimov.

11 recordsLinked to original sources
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[Biodiversity in plankton, benthos, and fish communities, and ecosystems of fresh water bodies with various productivity].

The species diversity of phyto- and zooplankton, benthic animals, and ichthyofauna was studied in continental water bodies that differ in type, geographic location, size, and productivity. The results showed that the number of species in the communities of aquatic organisms and in ecosystems depends on the area and volume of the water body and the level of plankton primary production. Corresponding relationships can be approximated by the equations of exponential and polymodal functions. The species number and biomass per unit area or volume proved to decrease the area or volume of the water body increased. The greatest number of heterotrophic species was observed in water bodies whose primary production approached 1400 kcal/m2 per year. It is proposed that the number of aquatic species in a body of water depends on the total area of the latter and the area of individual territories occupied by the representatives of certain species.

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[Territoriality in aquatic animals and their sizes].

The concept of territoriality proposed by E. Odum was used in this study. The territories were determined that were occupied by individuals of specific animal species and the notion "territory of individual" was proposed. The territories of individuals for different representatives of aquatic animals, including fish, were calculated and their relationships with mass and energy potential of animals were established. The territories of individuals and home ranges were compared in invertebrates and vertebrates. It was shown that for the entire animal world the relationship of these areas and mass can be described by a power equation with the exponent indistinguishable from 1. It was established on the example of zooplankton and zoobenthos communities that animal species with a larger size obtain advantage in the oligotrophic water bodies, since when the territories of individuals increase, they are capable of obtaining the necessary amount of food objects at their low density in such conditions. On the contrary, in the eutrophic water bodies, smaller animals have advantage, since they are capable of obtaining the necessary amount of food at a small home range and high density of food objects. A hypothesis was put forward that large and largest aquatic animals can occur in sea and oceanic waters not only because these are huge water basin, but also because these waters are, on the most part of territories, less productive, as compared to continental water bodies. In these conditions, the animals have to hunt over big territories for the necessary amount of food to be obtained and only large animals are able to do this.

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[The regularities in connection between fecundity with body weight and growth rate in fishes].

The absolute and relative fecundity of freshwater, anadromous and marine fishes (102 species and subspecies from 33 families) and its dependence on body mass and growth rate were analyzed on the basis of published data. According to the spawning type all studied fishes were divided into species with short-term and single spawning and fishes with extended or long-term spawning. The equations of dependence of absolute fecundity (E) on body mass (W) were calculated: E = 1.033 W0.578 (the first group) and E = 0.792 W0.74 (the second group). If W < 177 g the equations don't differ significantly and one may use the equation E = 1.34(-0.742) for both groups. The body mass of females at age of maturity expressed as a portion of maximal definitive body mass equals 0.22 +/- 0.044 for many different species with 0.95 probability. The relative fecundity (a1) of some species negatively correlates with maximal body mass of adult individuals (Wmax). This dependence is expressed by equations: a1 = 3.033 Wmax-0.549 (for the first group) and a1 = 1.726 Wmax-0.351 (for the second group). Value of ratio Wov/W of different fish species changes irregularly from 0.054 to 0.32 and its average is 0.150 +/- 0.012 for the first group and 0.156 +/- 0.007 for the second one. In such a way, single reproduction effort of fishes is approximately 0.15. Comparison of data on Pisces, Crustacea, Amphibia, Reptilia, and Mammalia revealed that reproduction effort of different aquatic and terrestrial invertebrates and vertebrates varies within rather narrow limits (from 0.05 to 0.44). Average values of this index varies even less--from 0.097 to 0.238, on average 0.162, i.e. approximately 15-18% of animals' body mass falls on their reproduction constituent.

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[Relationships between basic life history parameters and population size].

We consider an ideal population with a stable age composition changing according Lotka equation. Additional assumptions are made concerning the constancy of population size, independence of specific mortality rate on age, and linear dependence of female fecundity on its weight. A relationship has been obtained [formula: see text] where N0 is initial numbers of a generation, N[alpha, omega] is total numbers of the mature part of the population, w[alpha, omega] is a mean weight of a mature individual, s is sex ratio, c is specific fecundity (per unit of weight) and l0 is the probability of larval surviving. The growth of an individual is described by the Bertalanffy function. Methods of calculation of life history parameters are discussed. A method is proposed to calculate the age of maturity (alpha) and at the end (omega) of the reproduction period as first and second inflection points of the growth rate curve. Based upon data on development of 27 populations of several species of fishes of inland waters of Russia the following relationship have been obtained: [formula: see text] for populations with [formula: see text] < or = 100 g, [formula: see text] for populations with [formula: see text] > 100 g, and [formula: see text] for all populations.

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[A concept of relation between physical and biological time in animals].

A definition is proposed for biological ("internal") time tau(t) for a growing organism whose weight variation obeys the law w(t): tau(t) = 1/c(w) (t) = w(t)/w'(t), where t is physical ("external") time, w'(t) is weight increase rate, and c(w) (t) = w'(t)/w(t) is specific growth rate. Properties of functions tau(t) and w(tau) were studied for those cases when growth curves w(t) were described by Bertalanffy's or logistic equations.

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