Küljejoone asümmeetria katsetiikidesse asustatud ahvenatel (Perca fluviatilis)
Laen...
Kuupäev
2026
Kättesaadavus
08.09.2026
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Kalad tajuvad ümbritsevat mitmete meeleelundite abil, üheks olulisemaks neist on küljejoon kahel pool keha külge. Enamasti on see singulaarne augustatud soomuste rida, kuid osadel kalaliikidel esineb seal mitmeid variatsioone. Euroopa ahven (Perca fluviatilis) on üks nendest liikidest, kellel on kirjeldatud küljejoone asümmeetriat ja selle nn. hargnemist. Tänaseni on seda fenomeni täheldatud vaid mõnes üksikus humiinses ja madala pH järvedes, kuid nende mõju nt. ahvena kasvuedukusele on senini jäänud tähelepanuta. Käesoleva bakalaureusetöö eesmärk on kirjeldada asümmeetrilise küljejoone esinemist Kuulma järvest pärit ahvenate järglastel, uurimaks asümmeetrilise küljejoone esinemist F1 põlvkonnal ning võrrelda kahe erineva tunnusega isendite kasvu ja kehamassiindeksit. Andmestik koguti 669 kalalt, mis koguti viiest erinevate omadustega katsetiikidest, kus kalad kasvasid ühe kasvusuve. Tulemused näitasid, et F1 põlvkonna ahvenatel avaldusid samuti asümmeetrilise küljejoone tunnused ning nende kasv oli võrreldes normaalse küljejoonega isenditega oluliselt kiirem kuigi nende esinemissagedus oli madal (alla 30%). Antud töö tulemused viitavad sellele, et erinevad küljejoone fenotüübid ei ole hälve või ainult madalast pH tasemest põhjustatud. Katse tulemused vihjavad sellele, et küljejoone asümmeetria esinemisel võib olla geneetiline taust ning see võib aidata ahvenatel ellujääda ka väga rasketes oludes, mis teistele kalaliikidele võimatu.
Fish perceive their surroundings through several sensory organs, one of the most important being the lateral line located along both sides of the body. In most cases, it consists of a single row of perforated scales, although various modifications occur in some fish species. The European perch (Perca fluviatilis) is one the species in which lateral line asymmetry and so-called branching have been described. To date, this phenomenon has only been observed in a few humic, low-pH lakes, and its effects on perch, such as growth success, have largely been overlooked. The aim of this bachelor's thesis is to describe the occurrence of asymmetric lateral lines in the offspring of perch originating from Lake Kuulma, in order to investigate the presence of this trait in the F1 generation and to compare the growth and body condition index of individuals exhibiting different lateral line characteristics. The dataset consisted of 669 fish collected from five experimental ponds with differing environmental characteristics, where the fish were reared for one growing summer. The results showed that traits associated with lateral line asymmetry were also expressed in the F1 generation of perch and that these individuals exhibited significantly faster growth than individuals with a normal lateral line, despite their relatively low frequency of occurrence (less than 30%). The findings of this study suggest that different lateral line phenotypes are not abnormalities or traits caused solely by low pH conditions. The experimental results indicate that lateral line asymmetry may have a genetic basis and could help perch survive under extremely harsh environmental conditions that may be unsuitable for other fish species.
Fish perceive their surroundings through several sensory organs, one of the most important being the lateral line located along both sides of the body. In most cases, it consists of a single row of perforated scales, although various modifications occur in some fish species. The European perch (Perca fluviatilis) is one the species in which lateral line asymmetry and so-called branching have been described. To date, this phenomenon has only been observed in a few humic, low-pH lakes, and its effects on perch, such as growth success, have largely been overlooked. The aim of this bachelor's thesis is to describe the occurrence of asymmetric lateral lines in the offspring of perch originating from Lake Kuulma, in order to investigate the presence of this trait in the F1 generation and to compare the growth and body condition index of individuals exhibiting different lateral line characteristics. The dataset consisted of 669 fish collected from five experimental ponds with differing environmental characteristics, where the fish were reared for one growing summer. The results showed that traits associated with lateral line asymmetry were also expressed in the F1 generation of perch and that these individuals exhibited significantly faster growth than individuals with a normal lateral line, despite their relatively low frequency of occurrence (less than 30%). The findings of this study suggest that different lateral line phenotypes are not abnormalities or traits caused solely by low pH conditions. The experimental results indicate that lateral line asymmetry may have a genetic basis and could help perch survive under extremely harsh environmental conditions that may be unsuitable for other fish species.
Kirjeldus
Bakalaureusetöö
Kalanduse ja rakendusökoloogia õppekaval
Märksõnad
bakalaureusetööd, ahven, küljejoone asümmeetria, kohastumus, vee pH