Age composition and linear growth of the invasive ark clam species (Anadara kagoshimensis (Tokunaga, 1906)) in the Kerch Strait
Age composition and linear growth rate in the ark clam (Anadara kagoshimensis) population in the Kerch Strait are investigated. Based on the analysis of seasonal annual growth rings and chevron grooves on the hinge ligament of the ark clam, the age of this species has been examined, which, in this population, was found to be 7 years (6+). Based on the age and annual length gain of the molluscs in the course of their ontogenesis, a theoretical growth curve is presented; it has been calculated following the von Bertalanffy growth equation, where L∞, k, and t are the parameters equaling to 50.2, 0.428, and 0.022, respectively. The highest growth rate was observed in the first year of life, 17 mm; however, later on, it was consistently decreasing and did not exceed 2 mm/year in the oldest individuals. The relationship between the ark clam’s growth rate (PL) and its length, approximated by the inverse linear function is presented. Based on the parameters of the von Bertalanffy growth equation, a theoretical maximum age of the investigated species has been calculated; it was found to be 8.74 years. It has been shown that the linear growth rate of the ark clam in various areas of the Azov and Black Sea Basin is determined by the water salinity to a considerable extent, because in the desalinated areas (Azov Sea, Kerch Strait, Danube River Delta and Northwestern Black Sea with 10–14 ‰ salinity), the growth rate of this mollusc was 1.5–2 times lower than in the Southeastern Black Sea (18 ‰).
| Main Authors: | , , |
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| Format: | Journal Contribution biblioteca |
| Language: | Russian |
| Published: |
2022
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| Subjects: | Anadara kagoshimensis, Growth rings, Chevron grooves, Salinity effects, Von Bertalanffy equation, Ark clam, Годовые слои, Анадара, Шевронные борозды, ASFA_2015::A::Age composition, ASFA_2015::G::Growth rate, ASFA_2015::M::Marine molluscs, |
| Online Access: | http://hdl.handle.net/1834/41952 |
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| Summary: | Age composition and linear growth rate in the ark clam (Anadara kagoshimensis) population in the Kerch Strait are investigated. Based on the analysis of seasonal annual growth rings and chevron grooves on the hinge ligament of the ark clam, the age of this species has been examined, which, in this population, was found to be 7 years (6+). Based on the age and annual length gain of the molluscs in the course of their ontogenesis, a theoretical growth curve is presented; it has been calculated following the von Bertalanffy growth equation, where L∞, k, and t are the parameters equaling to 50.2, 0.428, and 0.022, respectively. The highest growth rate was observed in the first year of life, 17 mm; however, later on, it was consistently decreasing and did not exceed 2 mm/year in the oldest individuals. The relationship between the ark clam’s growth rate (PL) and its length, approximated by the inverse linear function is presented. Based on the parameters of the von Bertalanffy growth equation, a theoretical maximum age of the investigated species has been calculated; it was found to be 8.74 years. It has been shown that the linear growth rate of the ark clam in various areas of the Azov and Black Sea Basin is determined by the water salinity to a considerable extent, because in the desalinated areas (Azov Sea, Kerch Strait, Danube River Delta and Northwestern Black Sea with 10–14 ‰ salinity), the growth rate of this mollusc was 1.5–2 times lower than in the Southeastern Black Sea (18 ‰). |
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