ΜΕΛΕΤΗ ΟΡΜΟΝΩΝ ΤΟΥ ΘΥΡΕΟΕΙΔΗ ΣΤΗΝ ΙΡΙΔΙΖΟΥΣΑ ΠΕΣΤΡΟΦΑ, ΜΕ ΜΕΤΑΘΕΣΗ ΤΗΣ ΓΕΝΕΤΙΚΗΣ ΩΡΙΜΟΤΗΤΑΣ ΑΠΟ ΤΡΟΠΟΠΟΙΗΣΗ ΤΗΣ ΦΩΤΟΠΕΡΙΟΔΟΥ

THE AIM OF THIS STUDY WAS TO INVESTIGATE: A) THE EFFECT OF PHOTOPERIOD IN GONADOL MATURITY AND SPAWNING TIME OF TWO STRAINS OF RAINBOW TROUT (SALMO GAIRDUERI SHASTA/KAMLOOPS), B) THE EFFECT OF PHOTOPERIOD ON PLASMA THYROID HORMONES AND C) THE ROLE OF THYROID HORMONES IN TROUT GONADOL MATURITY DURING THE 1ST AND 2NDREPRODUCTIVE CYCLE. TWO SEASONALLY-CHANGING PHOTOPERIOD REGIMES WERE USED. BOTH STRAINS RESPONDED SIMILARLY TO THE CHOSEN ARTIFICIAL REGIME. EXPOSURE OF TROUT TO THE "LONG" SPRING DAYS PROTOCOL ACCELARATED SPAWNING 8-13 WEEKS AND EXTENDED (ABOUT FOUR FOLDS) THE DURATION OF SPAWNING PERIOD. THE "REVERSE" REGIME DELAYED SPAWNING 5-8 WEEKS AND DIMINISHED THE DURATION OF SPAWNING PERIOD . NO STATISTICAL DIFFERENCE OCCURED IN THE QUALITY AND QUANTITY OF EGGS AND FRY, IN ALLGROUPS. SEASONAL VARIATIONS OF THYROID CIRCULATING HORMONES (T3, T4) AND ALSO IN THE RATIO T4/T3 OCCURED IN BOTH STRAINS. NO STATISTICAL DIFFERENCE WAS FOUNDIN T3, T4 LEVELS BETWEEN MALE AND FEMALE TROUT. MAXIMUM CONCENTRATIONS OF T3, T4 WERE RECORDED IN LATE WINTER-EARLY SPRING AND MINIMUM DURING SPAWNING. STATISTICALLY LOWER VALUES OF T3, T4 WERE FOUND IN MATURE FEMALE FISH AS COMPARED TOIMMATURE. A SEX-RELATED DIFFERENCE IN PLASMA T3, T4 LEVELS AND MATURITY STAGESWAS OBSERVED. SEVERAL DIFFERENCES WERE FOUND IN THE ABSOLUTE AND RELATIVE T3, T4 CONCENTRATIONS AND ALSO IN THE PROFILE OF THYROID HORMONES BETWEEN THE 1ST AND 2ND REPRODUCTIVE CYCLE. SIMILAR PROFILE OF SEASONAL VARIATIONS OF T3, T4 OCCURED IN THE TWO STRAINS.

Grantor dc:publisher

National and Kapodistrian University of Athens

Year dc:date

1990

Authors dc:creator

• Pavlidis, Michail
• Παυλίδης, Μιχαήλ

• Αναπαραγωγή
• Θυρεοειδής
• Ιριδίζουσα πέστροφα
• Ορμόνες
• ΦΩΤΟΠΕΡΙΟΔΟΣ
• Hormones
• PHOTOPERIOD
• Rainbow trout
• Reproduction
• Thyroid
• Φυσικές Επιστήμες
• Βιολογία
• Natural Sciences
• Biological Sciences

Language dc:language

gre

Identifier

10.12681/eadd/1296

OAI identifier oai:identifier

oai:10442/1296