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Taphonomy of Oligocene teleost fishes from the Outer Carpathians of Poland

Bieńkowska-Wasiluk M.

Acta Geologica Polonica

2010

Vol. 60, no. 4

479-533

The Oligocene ichthyotaphocoenoses from the Outer Carpathians of Poland are dominated by skeletons of actinopterygian (only teleost) fishes. Their taphonomy was studied in six localities of the Menilite-Krosno Series (Błażowa, Jamna Dolna 1, Jamna Dolna 2, Rudawka Rymanowska, Wola Czudecka, Wujskie). Over 1700 specimens of variably complete fish skeletons, representative of 20 actinopterygian families, were studied. The taphonomic analysis of the skeletal disarticulation and its pattern, deformations of the vertebral column (curved, broken), arrangement of jaws and fins, the spatial array of skeletons with regard to the embedding sediment, as well as identification of unusually preserved specimens, indicate that all of the ichthyotaphocoenoses have resulted from a long-term accumulation of fish carcasses at the burial place, at a very low sedimentation rate, under anoxic conditions in, and above, the sediment/water interface. Two assemblages from the Tylawa Limestone Horizon have acquired their unusually good preservation state due to the penetration of calcium carbonate into soft tissues of corpses at the burial place. in other deposits (shales, marls) the fish skeletons are more or less disarticulated as a result of decay in a calm environment. each of the ichthyotaphocoenoses displays some features indicative of mass mortality events (e.g. high density of individuals, the presence of individuals with jaws agape, high number of juveniles); none of them has a set of features indicating it unequivocally. The cause and/or conditions of death were not the same for all individuals. Only some individuals died instantaneously during mass mortalities, whereas the majority died over a period of time as a result of senility, diseases, or other circumstances. all of the ichthyotaphocoenoses show features typical of both necro- and thanatocoenoses. The associated flora and fauna, e.g., amphipods, land-derived dragonflies and bird feathers, indicate that the taphocoenoses originated as a result of accumulation of biotic remains from various environments. Fishes and associated remains settled on the bottom successively, and thus their assemblages display features typical of necrocoenoses. evidence of fish predation is reported for the first time from the Menilite-Krosno Series of Poland.

Mercury contamination of tissues and organs of pike (Esox lucius L. 1758)

Żarski T. P., Ożóg A., Żarska H., Budzińska-Wrzesień E., Majdecka T.

Ecological Chemistry and Engineering. A

2008

Vol. 15, nr 9

1011-1017

The aim of the study was examination in which tissues and in what quantity predatory fish accumulates the highest amount of mercury. Concentration of mercury were determined in tissues and organs of pikes. Ten fish were bought in fish wholesale firm in Warsaw. Analyzed material comprised samples of chosen tissues like: scales, skin, fins, skeleton, muscles, a liver, spleen, swinbladder, heart, bones, frontal and dorsal kidneys, spawn or milt, eyes, gills, brain and intestine. Before collecting samples of tissues, the fish were measured and weighed with 10-1 g and samples were a weighed with accuracy of 10-3 g. 16 samples were collected for each fish. Mercury was determined by the atomic absorption spectrometry method using traces mercury analyzer AMA 254 controlled by the computer program AMA. The investigation demonstrated that mercury quantity in tissues depends on mass and age of fish. In pike the highest level of mercury was in muscles, considerable amounts were found also in guts and liver which indicates that the digestive system was the main way of absorbing mercury.

Celem pracy było stwierdzenie, w których tkankach i w jakiej ilości kumuluje się rtęć w organizmie szczupaka. Badania przeprowadzono u 10 śniętych szczupaków zakupionych w hurtowni na terenie Warszawy. Ryby poddano dysekcji i wypreparowano tkanki i narządy, tj: łuski, skórę, płetwy, szkielet, mięśnie, wątrobę, śledzionę, serce, pęcherz pławny, nerkę przednią i grzbietową, ikrę lub mlecz, oczy, skrzela, mózg dyrekcji jelito. Przed dysekcją całą rybę zważono i zmierzono, a po dysekcji wyznaczono masę poszczególnych tkanek i narządów z dokładnością do 10-3 g. W sumie z każdej ryby pobrano 16 próbek do dalszych badań. Zawartość rtęci w tkankach i narządach obliczono z iloczynu masy i stężenia tego pierwiastka w badanym materiale. Stężenie rtęci oznaczano przy użyciu automatycznego analizatora śladów rtęci AMA 254 metodą spektrometrii absorpcji atomowej pod kontrolą programu komputerowego AMA. Stwierdzono, że największe ilości rtęci występują w mięśniach, w jelicie i w wątrobie, co wskazuje, że droga pokarmowa jest głównym szlakiem wchłaniania rtęci. Stwierdzono także, że koncentracja rtęci w tkankach i narządach jest zależna od wieku i masy ryby.