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首页> 外文会议>Colloquium Crustacea Decapoda Mediterranea >Selectivity parameters and size at first maturity in deep-water shrimps, Aristaeomorpha foliacea (Risso, 1827) and Aristeus antennatus (Risso, 1816), from the North-Western Ionian Sea (Mediterranean Sea)
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Selectivity parameters and size at first maturity in deep-water shrimps, Aristaeomorpha foliacea (Risso, 1827) and Aristeus antennatus (Risso, 1816), from the North-Western Ionian Sea (Mediterranean Sea)

机译：深水虾的第一次成熟度，Aristaeomorpha Foliacea（Risso，1827）和Aristeus Antennatus（Risso，1816），来自西北海洋海（地中海），选择性参数和尺寸

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Selectivity experiments were carried out during trawling targeting deep-water shrimps Aristaeomorpha foliacea ('Risso, 1827) and Aristeus antennatus (Risso, 1816) (Crustacea, Decapoda, Aristeidae) in the North-Western Ionian Sea (Eastern-Central Mediterranean). Different criteria were employed to analyse maturity; however, the proportion at 50% of retained, mated and mature specimens was always used to indicate the size, expressed as Carapace Length (CL, mm), at first capture (CLC), mating (CLsp) and at first maturity (CLm), respectively. In order to estimate the size at 50% maturity (CLm) for females of both species, three criteria were adopted. In particular, CLm was computed for the mature females not considering the presence of spermatophores, for the mature females with spermatophores and for the mature females intersected by the decreasing proportion with size of females without spermatophores. Three diamond stretched mesh codends of 40, 50 and 60 mm were tested using a cover of 20 mm.The 40-mm stretched mesh size (European Union legal size in the Mediterranean) was not selective for the sampled population of each species. The size at first capture (CLC), calculated in both species for the two sexes combined, increased significantly with mesh size. Even for the mesh size of 60 mm, the size at first capture was still smaller than the sizes at 50% maturity, whatever the criterion adopted. Since the differences between the size at first maturity and the sizes at first capture are greater in A. foliacea than A. antennatus, the former species appears in this respect to be more vulnerable to trawling than the latter.
机译：选择性实验期间在靶向深水虾菌叶片（'Risso，1827）和Aristeus Antennatus（Risso，1816）（甲壳质，1816）（Craustacea，Decapoda，Aristeidae）的射击中进行了选择性实验。采用不同的标准来分析成熟;然而，50％的保留，交配和成熟样品的比例始终用于表示尺寸，表示为甲壳长度（Cl，mm），首先捕获（CLC），配合（CLSP）和第一成熟度（CLM） ， 分别。为了估计两种物种的女性的50％成熟度（CLM）的规模，采用了三个标准。特别地，对于未考虑生长素的成熟雌性的成熟雌性计算成熟的女性，对于具有精菌的成熟雌性的成熟雌性，并且对于在没有精子的雌性的大小的情况下与雌性的大小相交的成熟女性，而不是没有精子的成熟雌性的成熟女性。使用20mm的盖子测试40,50和60mm的三个金刚石拉伸网格编码。40mm拉伸网格尺寸（地中海的欧盟法律规模）对每个物种的采样群没有选择。在两种性别的两种种类中计算的第一次捕获（CLC）的大小随着网格尺寸而显着增加。即使对于网格尺寸为60毫米，仍然捕获的尺寸仍然小于成熟度的50％的尺寸，无论采用的标准如何。由于在第一次成熟度和第一次捕获时尺寸的尺寸之间的差异比A.叶肌大于A.Antennatus，因此在这方面出现了前面的物种比后者更容易捕获。

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