Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: The effect of temperature on photo- and geotaxis in the nauplii of the barnacles Balanus glandula (Darwin) and Pollicipes polymerus
Student Author(s): Umber, James S.
Faculty Advisor(s): Lee, Welton L.
Pages: 30
Location: Final Papers Biology 175H
Date: June 1967
Keywords: barnacle
cirripedia
Abstract: 1) Second stage Pollicipes polymerus (Sowerby) and second and third stage Balanus glandula (Darwin) tend to be negatively phototactic at higher temperatures and positively phototactic at lower temperatures. 2) The effect of temperature on naupliar behavior is never absolute. Nauplii appeared capable of adaption to both increased temperature and increased light intensity. 3) Second stage P. polymerus nauplii were found to be negatively geotactic in complete darkness. This upward migration could be stopped by warm water thermoclines of both 9 to 18 degrees C and 12 to 16 C. 4) Negative phototaxis ellicited by a beam of 3000 foot-candles could be stopped by cold waters of 7 to 7.2 C. 5) An apparent interaction of negative phototaxis and positive geotaxis seems to account for the downward migration of Pollicipes nauplii. 6) The possibility that early stages of Pollicipes and Balanus nauplii exhibit diurnal migration in the field is discussed.