Uzroci obojenja mišićnog tkiva svježeg brancina (Dicentrarchus labrax) žučnim bojama

master's thesis

• Title (english): Causes of coloration of muscular tissue at fresh sea bass (Dicentrarchus labrax) with bile pigments
• Author: Nikolina Ledenko
• Mentor: Tea Tomljanović (mentor)
• Committee member: Tea Tomljanović (predsjednik povjerenstva)
• Committee member: Daniel Matulić (član povjerenstva)
• Committee member: Marina Piria (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Fisheries, Beekeeping, Game Management and Special Zoology); Zagreb
• Defense date and country: 2019-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Obojanost mišićnog tkiva žučnim bojama nastaje kao normalna postmortalna promjena kada stijenka žučnog mjehura uslijed smrti stanica postaje propusna, te se žuč preslikava na okolna tkiva. Ako je žučni mjehur naslonjen na mišićno tkivo preslikavanje će se odraziti i na mišićnom tkivu. Cilj istraživanja je provjera potencijalnih čimbenika: temperature mora, dana gladovanja, odležavanja ribe na ledu, indeksa kondicije, težine žučnog mjehura, težine jetre na pojavu obojenja mišićnog tkiva žučnim bojama svježeg brancina (Dicentrarchus labrax). Pokus je proveden na 2 kaveza, jedan kavez je bio kontrolni nad kojim se vršila svakodnevna hranidba, a jedan pokusni u kojem je riba gladovala 10 dana po ciklusu. Vršena su 4 ciklusa uzorkovanja, a svaki ciklus je trajao 10 dana. U kontrolnom kavezu obrada odmah po izlovu se vršila 3., 5. i 10. dan, te nakon 24 h odležavanja na ledu od sva 3 puta uzorkovanja. U pokusnom kavezu obrada odmah po izlovu se vršila 6, 12, 24 h nakon zadnjeg hranjenja, a od drugog dana obrada se vršila jednom dnevno do 10. dana. Nakon 24 h odležavanja na ledu obrada se vršila nakon svakog dana uzorkovanja svih 10 dana po ciklusu. Prema rezultatima ovog istraživanja, gladovanje je utjecalo na obojenje mišićnog tkiva i na povećanje mase žučnog mjehura. Dulje trajanje gladovanja i dulje vrijeme proteklo od izlova do obrade ribe, rezultiralo je češćom i intenzivnijom pojavom obojanosti mišićnog tkiva žučnim bojama. Temperatura mora nije bila značajno povezana s obojanošću fileta, ali se njezin utjecaj odražava na indeks kondicije (IK), hepatosomatski indeks (HSI) i omjer mase žučnog mjehura i mase žučnog mjehura s jetrom (HI). Visceralna mast u utrobi ribe i oko žučnog mjehura reducirala je obojenje mišićnog tkiva žučnim bojama.

Abstract (english)

Coloration of fish musculuar tissue with bile pigments forms as a normal postmortal change when gallbladder wall due to "cell death" becomes permeable, and the bile is mapped to the surrounding tissues. If gallbladder leans on muscular tissue, the mapping will also affect muscle tissue. The aim of the study is a review of the potential factors: sea temperature, days of starvation, lying fish on ice, condition index, liver weight, gall bladder weight on the occurrence of coloration on muscular tissue at the fresh sea bass (Dicentrarchus labrax) with bile pigments. The experiment was carried out on 2 cages, one cage was the control over which daily nutrition was carried out, and the second cage was experimental in which fish were starved 10 days per cycle. Four sampling cycles were done, each cycle were lasting 10 days. In the control cage, evisceration immediately after harvesting was done on the 3rd, 5th and 10th day, and after 24 hours lying fish on ice at all three sampling times. In the experimental cage, evisceration immediately after harvesting was done 6, 12, 24 h after the last feeding, and from the second day the evisceration was done once daily until 10th day. After 24 hours of lying fish on ice, evisceration was doing after every day of sampling for 10 all days per cycle. According to the results of this study, starvation has affected the coloration of muscle tissue and the increase of gallbladder weight. The longer duration of starvation and the longer the time elapsed from harvesting till evisceration, resulted in a more frequent and intense appearance of coloration of muscular tissue. Sea temperature was not significantly related to the coloration of muscular tissue, but its influence reflected on the condition index (IK), the hepatosomatic index (HSI) and the ratio of the gall bladder weight and the weight of the gallbladder with the liver (HI). Visceral fat in the intestines of the fish and around the gallbladder reduced the coloration of the muscular tissue with bile colors.

• Keywords: Dicentrarchus labrax; žučni mjehur; obojenje; žučne boje; gladovanje
• Keywords (english): Dicentrarchus labrax; gallbladder; coloration; bile pigmests; starvation
• Language: croatian
• URN:NBN: urn:nbn:hr:204:927272
• Study programme: Title: Fisheries and Game Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka ribarstva i lovstva (magistar/ magistra inženjer/inženjerka ribarstva i lovstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-12-03 09:31:16