Fine Michael L, Waybright Tyler D
Department of Biology, Virginia Commonwealth University , Richmond, VA , United States.
Department of Biology, Virginia Commonwealth University , Richmond, VA , United States ; Office of Student Assessment, Virginia Department of Education , Richmond, VA , United States.
PeerJ. 2015 Oct 15;3:e1330. doi: 10.7717/peerj.1330. eCollection 2015.
As in insects, frogs and birds, vocal activity in fishes tends to be more developed in males than in females, and sonic swimbladder muscles may be sexually dimorphic, i.e., either larger in males or present only in males. Male oyster toadfish Opsanus tau L produce a long duration, tonal boatwhistle advertisement call, and both sexes grunt, a short duration more pulsatile agonistic call. Sonic muscles are present in both sexes but larger in males. We tested the hypothesis that males would call more than females by inducing grunts in toadfish of various sizes held in a net and determined incidence of calling and developmental changes in grunt parameters. A small number of fish were recorded twice to examine call repeatability. Both sexes were equally likely to grunt, and grunt parameters (sound pressure level (SPL), individual range in SPL, number of grunts, and fundamental frequency) were similar in both sexes. SPL increased with fish size before leveling off in fish >200 g, and fundamental frequency and other parameters did not change with fish size. Number of grunts in a train, grunt duration and inter-grunt interval were highly variable in fish recorded twice suggesting that grunt parameters reflect internal motivation rather than different messages. Grunt production may explain the presence of well-developed sonic muscles in females and suggests that females have an active but unexplored vocal life.
与昆虫、青蛙和鸟类一样，鱼类的发声活动在雄性中往往比雌性更发达，而且发声的鱼鳔肌肉可能具有两性差异，即要么在雄性中更大，要么只存在于雄性中。雄性牡蛎蟾鱼（Opsanus tau L）会发出持续时间长、音调似汽笛的求偶广告叫声，两性都会发出呼噜声，这是一种持续时间短、更具脉动性的争斗叫声。发声肌肉在两性中都存在，但在雄性中更大。我们通过在网中饲养的不同大小的蟾鱼中诱导它们发出呼噜声，检验了雄性比雌性叫声更多的假设，并确定了叫声的发生率以及呼噜声参数的发育变化。对少数鱼进行了两次记录，以检验叫声的重复性。两性发出呼噜声的可能性相同，而且两性的呼噜声参数（声压级（SPL）、SPL的个体范围、呼噜声的数量和基频）相似。声压级在鱼体重超过200克之前随鱼的大小增加，之后趋于平稳，基频和其他参数不随鱼的大小变化。在两次记录的鱼中，一连串呼噜声的数量、呼噜声持续时间和呼噜声间隔高度可变，这表明呼噜声参数反映的是内部动机而非不同的信息。呼噜声的产生可能解释了雌性中发达的发声肌肉的存在，并表明雌性有着活跃但尚未被探索的发声生活。
