Source of bigheaded carp (Hypophthalmichthysspp.) in Lake Balaton, Hungary: natural recruitment or continuous escapement from aquaculture?
| Autor: | Zoltán Vitál, Attila Mozsár, Piotr Hliwa, Vilmos Józsa, István Lehoczky, Balázs Kovács, Gergely Boros, András Specziár |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
Hypophthalmichthys business.industry 010604 marine biology & hydrobiology 04 agricultural and veterinary sciences Aquatic Science Biology Fecundity biology.organism_classification 01 natural sciences Fishery Gonadosomatic Index Aquaculture 040102 fisheries 0401 agriculture forestry and fisheries Asian carp sense organs Carp business Escapement Water Science and Technology |
| Zdroj: | Inland Waters. 7:218-226 |
| ISSN: | 2044-205X 2044-2041 |
| DOI: | 10.1080/20442041.2017.1319546 |
| Popis: | The worldwide spread of bigheaded carp (Hypophthalmichthys spp.) is considered an ecological threat and problem in many countries. The aim of this study was to consider the likelihood of bigheaded carp reproduction in Lake Balaton and its catchment area (Hungary). The within-year trends of gonadosomatic index values show that female bigheaded carp increase ovary masses from spring until midsummer, after which a decline is typical. This trend may indicate bulk egg release, but the lack of a sharp drop in fecundity (number of eggs in the ovary) values during and after the potential spawning period suggests that a general and considerable ovary evacuation does not likely explain the declining gonadosomatic index values. Rather, it is more probable that female bigheaded carp resorb their eggs, supported by the presence of atretic oocytes in the ovaries after the potential spawning season. In turn, postovulatory follicles were present in the posterior ovary segments of 2 individuals, indicating that ma... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|