Toksični učinak željeza na zelenu i smeđu hidru (Hydra viridissima I Hydra oligactis Pallas)

master's thesis

• Title (english): Toxic effect of iron on green and brown hydra (Hydra viridissima I Hydra oligactis Pallas)
• Author: Ana Matijević
• Mentor: Goran Kovačević (mentor)
• Committee member: Goran Kovačević (predsjednik povjerenstva)
• Committee member: Zdravko Dolenec (član povjerenstva)
• Committee member: Vesna Petrović-Peroković (član povjerenstva)
• Committee member: Davor Kovačević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2011, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Željezo je jedan od najraširenijih metala u Zemljinoj kori. Hidra je slatkovodna životinja koljena Cnidaria. Toksični učinak željeza na različite organizme bio je već predmet istraživanja, ali ovo je prvo dokumentirano istraživanje o njegovu učinku na hidre. Zelena hidra sadrži u svojim gastrodermalnim mioepitelnim stanicama simbiotsku algu. Jedinke simbiotske zelene hidre bile su tretirane sa šest koncentracija vodene otopine željeznog dekstrana, dok je nesimbiotska smeđa hidra bila tretirana s 14 koncentracija vodene otopine željeznog dekstrana tijekom tri dana. Morfološke promjene su praćene pomoću stereolupe i to migracija jedinki u eksperimentalnoj posudici, promjena oblika tijela, reakcija na mehanički podražaj, odsutnost lovki, lučenje sluzi i nespolno razmnožavanje. Migracija hidri je prvi način izbjegavanja štetnog učinka (mikro)okoliša, nakon čega je uslijedila promjena oblika tijela. Histološke promjene praćene su pomoću svjetlosnog mikroskopa. Morfometrijska istraživanja obuhvaćala su mjerenja površina ektoderma i gastroderma te debljine mezogleje. Depozicije željeza u tkivu hidri su bile vidljive su kao plavo obojenje unutar stanica. Visoke koncentracije željeza uzrokovale su morfološke i histološke promjene i letalni učinak. Zelena hidra je pokazala veću otpornost u preživljavanju od smeđe. Simbioza se pokazala kao evolucijska prednost.

Abstract (english)

Iron is among the most common metals in Earth's crust. Hydra is a freshwater animal that belongs to the phylum Cnidaria. Toxic effect of iron on various organisms has been investigated before but this is the first documented research on its effect on hydras. Green hydra contains symbiotic algae in its gastrodermal myoepithelial cells. Individuals of symbiotic green hydra were treated with six concentrations of aqueous solution of iron dextran, while aposymbiotic brown hydra was treated with 14 concentrations of aqueous solution of iron dextran for three days. Morphological changes migration of individuals in experimental dish, changes of body shape, reaction to mechanical stimuli, tentacle reduction, mucous secretion and asexual reproduction were monitored with stereolupe. Migration of hydras was the first step in evading deleterious microenvironmental conditions, followed by changing its body shape. Histological changes were observed with light microscope. Morphometric analysis included measuring of endoderm and gastroderm surface areas and mesoglea thickness. Iron depositions in hydra tissue were observed as blue staining within cells. High concentrations of iron caused morphological and histological changes and mortality. Green hydra showed a higher level of resistance in surviving than brown hydra. Symbiosis was pointed out as an evolutionary advantage.

• Keywords: hidra; željezni dekstran; toksičnost; simbioza; migracija; morfološke i histološke promjene; morfometrija
• Keywords (english): hydra; iron dextran; toxicity; symbiosis; migration; morphological and histological changes; morphometry
• Language: croatian
• URN:NBN: urn:nbn:hr:217:524974
• Study programme: Title: Biology and Chemistry; Study programme type: university; Study level: graduate; Academic / professional title: profesor biologije i kemije (profesor biologije i kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-04-09 09:43:34