Histopatološke promjene u hepatopankreasu signalnog raka Pacifastacus leniusculus (Dana, 1852) u Korani

master's thesis

• Title (english): Histopathological changes in hepatopancreas of the signal crayfish Pacifastacus leniusculus (Dana, 1852) in the Korana river
• Author: Ana Bekavac
• Mentor: Romana Gračan (mentor)
• Mentor: Sandra Hudina (mentor)
• Committee member: Romana Gračan (predsjednik povjerenstva)
• Committee member: Sandra Hudina (član povjerenstva)
• Committee member: Sofia Ana Blažević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2020, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Signalni rak predstavlja opasnost za autohtone vrste rakova zbog velike agresivnosti i dominacije u kompeticiji za resurse. Kako je hepatopankreas najvažniji energetski organ signalnog raka, promjene u njegovoj strukturi narušavaju i njegovu funkciju, a time i kondicijsko te cjelokupno zdravstveno stanje jedinke što može negativno utjecati na rast, reprodukciju i širenje ove vrste. U ovom radu prikupljene su i morfometrijski obrađene 73 jedinke signalnog raka, duž invazivnog areala u rijeci Korani. Jedinkama su izolirani hepatopankreasi te izrađeni trajni histološki preparati koji su analizirani svjetlosnim mikroskopom. Dobiveni rezultati pokazuju da 64% analiziranih rakova ima više od 25% tkiva hepatopankreasa zahvaćeno patološkim promjenama, pri čemu 14% životinja pokazuje teške promjene na više od 75% tkiva. Fokalna nekroza uočena je kod 53% jedinki, melanizacija kod 51%, a gram-pozitivne bakterije kod 44% jedinki. Ustanovljene histopatološke promjene indikatori su idiopatskog nekrotizirajućeg hepatopankreatitisa, čiji je uzročnik zasad još nepoznat. Sva histopatološka oštećenja zabilježena su s većom učestalošću u središtu invazivnog areala, gdje je gustoća jedinki veća, u odnosu na fronte širenja. Životinje s težim histopatološkim oštećenjima imale su značajno smanjeni hepatosomatski indeks, što ukazuje da ova bolest utječe na kondicijski status životinja, a time može utjecati i na daljnju brzinu širenja ove invazivne strane vrste.

Abstract (english)

Signal crayfish threatens native crayfish populations due to its high aggression and dominance in competitive interactions. Since hepatopancreas is the main energy supply organ in crayfish, changes in its structure alter its function and affect its condition and overall health. This can consequently lead to negative impacts on animal growth, reproduction and range expansion. In this research, 73 individuals along signal crayfish invasion range in the Korana river were collected. Hepatopancreases were isolated, fixed histological slides were prepared and analyzed with the light microscope. Results of this experiment show that 64% of analyzed crayfish had more than 25% of tissue with pathological changes, with 14% of crayfish having more than 75% of tissue with heavy changes. Focal necrosis was observed in 53% of cases, while melanisation in 51% and Gram-positive bacteria in 44%. The aetiology of observed histopathological changes indicates idiopathic necrotizing hepatopancreatitis whose cause still remains unknown. All histopathological changes were more frequent in the invasion core, where population density is higher, opposed to invasion fronts. Heavy histopathological changes in hepatopancreas correlated with low hepatosomatic index which indicates that this disease affects the condition of the animal and may affect range expansion of this invasive alien species.

• Keywords: invazivne strane vrste; hepatopankreas; kondicija; histopatologija; bakterije
• Keywords (english): invasive alien species; hepatopancreas; condition; histopathology; bacteria
• Language: croatian
• URN:NBN: urn:nbn:hr:217:162123
• Study programme: Title: Experimental Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra eksperimentalne biologije (magistar/magistra eksperimentalne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2021-06-26
• Created on: 2020-06-30 08:11:54