Kindler P M, Bahr J M, Philipp D P
Department of Animal Sciences, University of Illinois, Urbana-Champaign 61801.
Horm Behav. 1991 Sep;25(3):410-23. doi: 10.1016/0018-506x(91)90011-6.
This study investigated the effect of exogenous 11-ketotestosterone (11KT) and testosterone (T), two important androgens involved in fish reproduction, as well as cyproterone acetate (CYA), an antiandrogen, on behaviors of male bluegill (Lepomis macrochirus) during prespawning and parental care periods. Parental male bluegill build nests in colonies, spawn with females, and then remain alone on these nests to provide care for their developing offspring. Implantation of pellets containing either 11KT or T did not induce parental males to build nests in early spring, before the onset of natural spawning, or during late spring and early summer, when the reproductive season was in progress. Treatment with pellets containing CYA inhibited reproduction in male bluegill and these fish did not spawn for the remainder of the reproductive season. The release of appropriate steroids from pellets to the serum was confirmed in all cases by a radioimmunoassay. Interestingly, nesting males that spawned successfully and were implanted with 11KT at the onset of the parental care phase displayed increased rim-circling, a behavior characteristic of the late prespawning period. Treatment with T or CYA, however, did not induce such behaviors in nesting bluegill. Finally, none of these treatments significantly affected antipredator aggressive behavior displayed by nesting males. Our results suggest that parental care behaviors in male bluegill are most likely expressed through nonandrogenic mechanisms.
本研究调查了外源性11-酮睾酮（11KT）和睾酮（T）这两种参与鱼类繁殖的重要雄激素，以及抗雄激素醋酸环丙孕酮（CYA）对雄性蓝鳃太阳鱼（Lepomis macrochirus）在产卵前和育幼期行为的影响。育幼期的雄性蓝鳃太阳鱼会在群体中筑巢，与雌性交配，然后独自留在这些巢中照顾发育中的后代。在早春自然产卵开始前，或在晚春和初夏繁殖季节进行期间，植入含有11KT或T的药丸并不会促使育幼期雄性蓝鳃太阳鱼筑巢。用含有CYA的药丸进行处理会抑制雄性蓝鳃太阳鱼的繁殖，并且这些鱼在繁殖季节的剩余时间内都不会产卵。通过放射免疫测定法在所有情况下均证实了药丸中的类固醇向血清的释放。有趣的是，在育幼期开始时成功产卵并植入11KT的筑巢雄性蓝鳃太阳鱼表现出增加的沿边缘绕圈行为，这是产卵前后期的一种行为特征。然而，用T或CYA进行处理并未在筑巢的蓝鳃太阳鱼中诱导出此类行为。最后，这些处理均未显著影响筑巢雄性蓝鳃太阳鱼表现出的反捕食攻击行为。我们的结果表明，雄性蓝鳃太阳鱼的育幼行为很可能是通过非雄激素机制表达的。
