Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 43

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The close phylogenetic relatedness among eels and their many species often necessitates applying genetic studies (PCR-RFLP) to identify the various species within the order Anguilliformes. This article presents a method for differentiating between European and Japanese eel based on the dentition of the upper jaw and the mouth cavity vault (vomer section). In European eel the row of teeth at the edge of the jaw is wider and has more teeth in comparison to that of the Japanese eel. The lengths and widths of the middle strip of the mouth cavity vaults are longer and wider in European eel than in Japanese eel.
Studies of the sex structure and recruitment rates of silver eels from a population occurring in natural conditions in a large lake complex were conducted in the 1985-1990 period based on a sample of 6998 specimens. The fish were caught in 60 connected lakes with a combined surface area of 300 km2 using box traps, cross traps, stownets on stakes and electric fishing. It was determined that the share of males in the eel population occurring in the lakes was barely 1.03%, and in the group of fish with body lengths (Lt) of up to 46.0 cm it was 3.17%. Silver and yellow eels were noted among both males and females. The share of silver eels increased from 0 to 100% in the body length categories from 39.0 to 46.0 cm among males and from 47.5 to 95.0 cm among females. In both instances, the dependence of the share of silver eels on the total length of the body was described with linear regression with a high correlation coefficient and high regression significance (P < 0.05). The studies indicated that in the lakes of northeastern Poland, which are located within a large complex that is permanently connected, the share of males is small and the recruitment of silver eels from this group occurs within a narrower and lower size range than it does in females.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 3 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.