Wyniki wyszukiwania

1

Woreczek żółtkowy u ryb kostnoszkieletowych

100%

Witeska M., Bilska K.

Komunikaty Rybackie

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2013

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nr 6

Yolk is a source of nutrients for developing embryos and for early fish larval stages that lack the ability to feed actively. Thanks to abundant networks of capillaries, yolk sacs are responsible for larval respiration before the development of gills, and in some fish species they are also the site of primary hematopoiesis. Fish yolk sac shapes and sizes differ among species. Cold-water fish with long periods of embryonic and larval development have larger yolk sacs as compared to those of warm-water species. Yolk comprises free amino acids, proteins, lipids, and minerals that are taken up by developing organisms through the yolk syncytial layers. Free amino acids and proteins are utilized before lipids. Yolk nutrients are divided between growth and energy production. The efficiency of yolk utilization for growth is higher in embryos, and then decreases with the increase in larval locomotion. The rate of yolk resorption depends mainly on water temperature, but it can also be modified by other environmental factors such as the availability of exogenous food or water that is contaminated with toxic compounds.

2

Ryby tęczankowate (Melanotaeniidae) jako obiekt badań

88%

Prusinska M.

Komunikaty Rybackie

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2016

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nr 3

3

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Ichthyoliths and deepening events in the Devonian carbonate platform of the Holy Cross Mountains

88%

Liszkowski J., Racki G.

Acta Palaeontologica Polonica

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1992

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tom 37

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nr 2-4

407-426

Disarticulated fish microremains from the Middle Givetian to early Frasnian of the Holy Cross Mts include representatives of the most groups known from the Devonian: placoderms, elasmobranchs, holocephalians, acanthodians, osteichthyans (mostly osteolepidids) and actinopterygians. Taxonomic identifications are possible usually only in very general terms and only in two cases the generic level has been reached: Phoebodus among euselachians, and Moythomasia among paleoniscids. Many of these groups, regarded traditionally as typical dwellers of lacustrine to resticted marine nearshore biotopes, apparently flourished also in the offshore, open shelf carbonate (peri-reefl settings. The sequential replacement of the fish faunas was primarily influenced by eustatic events, in like manner to invertebrate communities.

Ograniczanie wyników

2 Komunikaty Rybackie

1 Acta Palaeontologica Polonica

1 Bilska K.

1 Liszkowski J.

1 Prusinska M.

1 Racki G.

1 Witeska M.

1 2016

1 2013

1 1992

Woreczek żółtkowy u ryb kostnoszkieletowych

Ryby tęczankowate (Melanotaeniidae) jako obiekt badań

Ichthyoliths and deepening events in the Devonian carbonate platform of the Holy Cross Mountains