Ovarian alterations in wild northern pike Esox lucius females.
The aim of the present study was to analyse the occurrence of macroscopically visible ovary alterations in 2 populations of northern pike Esox lucius L. originating from lakes in the Mazurian Lake District (NE Poland). The alterations were characterised by ovary tissue that was morphologically malformed, in part or in whole, and contained immature oocytes, i.e. trophoplastic or previtellogenic oocytes instead of vitellogenic oocytes. These alterations were found only in the ovaries, and no morphological alterations of the testes were noted. Macroscopic and histological analyses were carried out in order to classify the observed alterations in the ovaries. Three types of alterations were identified in which morphological malformations as well as histological investigation of the ovaries were considered. An analysis of the size and age of the fish in relation to the occurrence of alterations as well as of the macroscopic and histological nature of the alteration types was made. The data obtained revealed no lake or age dependency of the observed alterations. Based on the results obtained, we suggest that the presence of endocrine disruptors in the environment or/and genetic factors could be responsible for these kinds of gonad anomalies. However, our results did not allow us to determine the aetiology of the alterations.
Department of Lake and River Fisheries, Department of Fish Culture and Department of Ichthyology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 5, 10-719 Olsztyn, Poland.
Daniel
D
Zarski
Jacek
J
Rechulicz
Sławomir
S
Krejszeff
Tomasz K
TK
Czarkowski
Katarzyna
K
Stańczak
Katarzyna
K
Palińska
Magdalena
M
Gryzińska
Katarzyna
K
Targońska
Krzysztof
K
Kozłowski
Andrzej
A
Mamcarz
Piotr
P
Hliwa
D000818:Animals; D017859:Esocidae; D005260:Female; D005393:Fish Diseases / Q000453:epidemiology / Q000473:pathology*; D010049:Ovarian Diseases / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D010053:Ovary / Q000473:pathology*; D011044:Poland / Q000453:epidemiology