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11-ketotestosterone is not responsible for the entire testicular effect on male reproductive behaviour in the threespine stickleback Erik Hoffmann 1,3) , Anna Österman 1) , Ian Mayer 2) & Bertil Borg 1) ( 1 Department of Zoology, Stockholm University, S-106 91 Stockholm, Sweden; 2 Department of

In: Behaviour

Social context may affect urinary excretion of 11-ketotestosterone in African cichlids Katharina Hirschenhauser 1,5) , Adelino V.M. Canário 2) , Albert F.H. Ros 3) , Michael Taborsky 4) & Rui F. Oliveira 3) ( 1 Konrad Lorenz Research Station Gruenau, University of Vienna, Austria; 2 Centro de

In: Behaviour

application of the non-invasive procedure requires more planning and validation than conventional plasma sampling. However, we consider that the rewards justify the extra effort. Keywords : review, fish, steroids in water, non-invasive, 11-ketotestosterone, cortisol. Introduction The non-invasive procedure

In: Behaviour

behaviours after eggs have been deposited in the nest (Meunier et al., 2009 ); however, it is surprisingly difficult to identify a reproductive male with certainty prior to egg deposition. Current measures of reproductive status in males include black nuptial colouration, elevated 11-ketotestosterone (11-KT

In: Behaviour

by gently squeezing their abdomens after each interaction period and urine volumes measured. Plasma samples for subsequent measurement of testosterone and 11-ketotestosterone levels were collected only after the second experiment ( N = 6

In: Behaviour

of the breeding stickleback. In breeding males the plasma levels of 11-ketotestosterone (11KT) are higher than those of other measured androgens, and display a clear peak in the breeding season. 11 KA can be converted extra-testicularily to 11KT. In breeding females the plasma levels of 11KT are

In: Behaviour

mechanisms controlling reproductive behaviour in these fishes. In order to investigate this question further, Páll et al . (2002a) studied in greater detail HORMONAL CONT ROL OF BE HAVIOUR IN ST ICKL E BACKS 1503 T ABLE 2. Changes in plasma 11-ketotestosterone levels between the sexual and parental

In: Behaviour

205 214 Van Den Hurk van De Kant H. The effect of methyltestosterone, 11-ketotestosterone and methallibure on gonadotropic cells, Leydig cells, spermatogenesis and the epithelium of the intratesticular efferent duct system of the juvenile male black molly Mollinesia latipinna 1975 275 286 Proc

In: Israel Journal of Ecology and Evolution

environmental stimuli, including the presence of eggs, change the be- haviours. 11-ketotestosterone (11KT) is the most important androgen in teleost fishes (Borg, 1994) and is known to stimulate several aspects of reproduc- tive behaviour in the stickleback (Borg & Mayer, 1995). There is a natural decline in

In: Behaviour

mediate across ecologically relevant environmental contexts in any species (Williams, 2008 ; Ketterson et al., 2009 ). Male guppy mating behavior is likely to be increased by the androgens testosterone (T) and 11-ketotestosterone (11KT) (Borg, 1994 ; Dzieweczynski et al., 2006 ; Hallgren et al., 2006

In: Behaviour