Embryonic development and functional readiness of the sound-transmitting system of acoustic analyzer in Larus gulls

Autor: L. I. Barsova, V. D. Anisimov
Rok vydání: 2012
Předmět:
Zdroj: Biology Bulletin. 39:593-600
ISSN: 1608-3059
1062-3590
Popis: Morphometric parameters of the developing sound-transmitting system of the peripheral acoustic analyzer have been studied in embryos of the common gull (Larus canus) and black-headed gull (L. ridibundus) beginning from the second half of the incubation period. The results show that structures of the outer ear and the middle-ear columellar complex at the stage corresponding to 77–79% of the incubation period have not yet completed morphogenesis and cannot perform their functions. At subsequent stages, morphometric characteristics of the columellar complex allow it to participate in sound transmission, but only in the air, while the embryos are still submerged in the amniotic fluid. Beginning from days 23–24 (88–92% of the incubation period) in L. canus and days 21–22 (87–91%) in L. ridibundus, the embryos perforate the shell membrane, start pulmonary respiration, and develop acoustic signaling. Since that time, the outer and middle ear become involved in continuous transmission of acoustic signal to the inner ear receptors.
Databáze: OpenAIRE