Fish eggs, larvae and juveniles occurring in the Shimanto estuary

石门托河口及邻近海域的幼鱼区与沿海和近海生境的差异明显，日本鳗鲡是目前的优势种。Mugil cephalus、Liza carinata、Terapon jarbua和Acanthopagrus schlegeli的存在，以及Blenniidaem、Sebasticus marmoratus和Callionymidae的缺失，将岸边水域的鱼系与河口中心水域的鱼系区分了出来，沙滩的海浪带也有一些泛盐和双栖鱼类。石门托河口沿岸水域的一些鱼类也在沙滩的冲浪区被收集。在这些物种中，主要栖息地被认为是上述两种生物群落中的一种。例如，对日本Lateolabrax japonicus来说，河口是一个主要的栖息地，但对latus来说不是。由此发现，占据河口岸水域的鱼苗和幼鱼群落是成功适应了河口盐度相对较低的环境的特殊物种。这三种sparines在幼年早期从非鳗草栖息地迁移到河口岸水域的鳗草床。因此，这些鱼类被归类为非大叶藻区域内的洄游物种，它们只在短时间内作为栖息地。因此，河岸水域的非大叶藻栖息地作为这些物种的苗圃的作用似乎类似于沙滩上的冲浪区，由迁徙物种占据。随后，它们居住在鳗草床中，至少直到幼鳗晚期或幼鳗阶段。在此期间，它们转变为生活习性，以鳗草床中的底栖动物为食。因此，大叶草床似乎在它们的定居中起着重要作用。因此，由非大叶藻区和大叶藻床组成的河口岸水域被认为是适应低盐度环境的特殊物种早期生活史的重要温床。少

The larval and juvenile ichthyofauna of the shimanto estuary and adjacent surf zones showed marked differences from that of the coastal and offshore habitats in the poorness of Engraulis japonicus, which occurs in those habitats as by far the dominant species. The presence of Mugil cephalus, Liza carinata, Terapon jarbua and Acanthopagrus schlegeli and the absence of Blenniidaem, Sebasticus marmoratus and Callionymidae distinguished the ichthyofauna of the bank waters from that in the center of estuary and surf zones of sandy beaches have something in euryhaline and diadromous fishes.Some of fish species occurring in the bank waters of the Shimanto estuary are also collected in the surf zones of sandy beaches. Among those species, the principal habitats is considered to be either of the two above-mentioned biotopes. For the Lateolabrax japonicus, for instance, the estuary is a main habitat, but not for the L.latus. Hence it is found that the community of fish larvae and juveniles mainl … More y occupying the bank waters of the estuary is an exceptional species which has successfully adapted to estuary environment characterized by a relatively low salinity condition.The three sparines move from non-eelgrass habitats to eelgrass beds in the bank waters of the estuary at the early juvenile stage. Thus those fishes are categorized as migrant species within the non-eelgrass area which they use as a hbitat only for a brief time. Consequently, it seems that the role of the non-eelgrass habitats in the bank waters as a nursery for these species is similar to that of the surf zones on sandy beaches that are occupied by migrant species. Subsequently, they reside in eelgrass beds at least until the late juvenile or young stage. During this timem, they transform to demersal habit, and feed on benthic animals in eelgrass beds. Thus the eelgrass beds seem to play an important role in their settlement.As a consequence, the bank waters of the estuary consisting of non-eelgrass areas and eelgrass beds is found to be an important nursery where the exceptional species adapted to low salinity environment can spend a great part of their early life history. Less