Spiny-backed orb-weaving spiders of the subfamily Gasteracanthinae are broadly distributed in the Old World. Despite their use as a model species in biology, evolution, and behavior because of their extraordinary characteristics, the systematics of this group of spiders are still poorly understood. This study elucidates the systematics of Gasteracanthinae in Thailand based on morphological and molecular-based analyses. In total, seven species from three genera, namely Gasteracantha, Macracantha, and Thelacantha, were recorded in Thailand. Shape of abdominal spines, pattern of sigilla, and female genitalia are significant characters for species identification. In contrast, coloration shows highly intraspecific variation in most species within Gasteracanthinae. A phylogenetic tree based on partial sequences of COI, 16S, and H3 genes recovered Gasteracanthinae as a monophyletic group and supports the existence of three clades. Gasteracantha hasselti is placed as a sister taxon to Macracantha arcuata. Hence, we propose to transfer G. hasselti to Macracantha. Moreover, molecular species delimitation analyses (ABGD, bPTP, and GMYC) using 675 bp of COI gene support all nominal species, with evidence of possible additional cryptic species.

中文翻译：

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在泰国的Gasteracanthinae亚科（Araneae，Araneidae）的多刺背球编织蜘蛛的分类学的审查。

菊科亚科的具刺背的球形编织蜘蛛在旧大陆广泛分布。尽管由于它们的非凡特征而被用作生物学，进化和行为的典范物种，但对这组蜘蛛的系统学却仍然知之甚少。这项研究阐明了基于形态学和分子分析的泰国菊科植物的系统学。在泰国总共记录了来自三个属的7种，分别是Gasteracantha，Macracantha和Thelacantha。腹棘的形状，Sigilla的模式和女性生殖器是识别物种的重要特征。相比之下，着色显示了菊苣科内大多数物种的种内高度差异。基于COI，16S，H3和H3基因将胃蠕虫科恢复为一个单系，并支持三个进化枝的存在。Gasteracantha hasselti被放置为Macracantha arcuata的姐妹分类单元。因此，我们建议将G. hasselti转移到Macracantha。此外，使用675 bp COI基因进行的分子物种定界分析（ABGD，bPTP和GMYC）支持所有标称物种，并可能存在其他隐性物种的证据。