A COMPARATIVE ANALYSIS OF THE GROWTH AND LIFESPAN OF OPHIACANTHA BIDENTATA RETZIUS 1805 (ECHINODERMATA, OPHIUROIDEA) IN THE HIGH LATITUDES OF THE RUSSIAN ARCTIC

摘要

Growth is known to be one of the key parameters in animal ecology. The rates and periodicity of growth are determined by the internal physiological characteristics of species and the external conditions of their habitat. The growth rates and their features were studied using Ophiacantha bidentata as an example. This species is widely distributed in the Arctic. The collection material of the Marine Research Laboratory of the Zoological Institute of the Russian Academy of Sciences was used for this research. The samples of O. bidentata analyzed were taken from two regions of the Russian Arctic: the Vikhr Strait (Franz Josef Land) and the Vilkitsky Strait. The determination of the individual age was performed through counting the ring-shaped growth marks in the calcite structure of the animal arm vertebrae. Each visible ring was considered as annual. The Gompertz equation was used as the basic mathematical model to describe the growth of this species. In the Vikhr Strait, the average value of the theoretically limit radius of the arm (R-infinity) of O. bidentata was 399 +/- 28 gm, the exponential deceleration of the specific growth rate (g) was 0.58 +/- 0.028. The parameters of group growth differed from the above-mentioned and were R-infinity = 476 +/- 28 mu m, g = 0.39 +/- 0.063. Similar calculations performed for the O. bidentata population from the Vilkitsky Strait showed that the average value of the theoretically limit radius of the arm was 398 +/- 25 mu m, the exponential deceleration of the specific growth rate was 0.39 +/- 0.018, the parameters of group growth were as follows: R-infinity = 495 +/- 23 mu m, g = 0.26 +/- 0.028. The maximum lifespan of O. bidentata in the study population from the Vikhr Strait (Franz Josef Land) was estimated to last 7-10 years, vs. 10-15 years for the Vilkitsky Strait population.