Crenidens macracanthus was originally described in 1874 based on a single specimen collected from Chennai (Madras), south-east coast of India. In 1875, the species was synonymized with C. indicus without citing any valid reason. Since then, no taxonomic studies have been attempted for the genus Crenidens, except in 2013 the species was resurrected from synonymy and redescribed as a valid species based on the holotype and non-type specimen. In view of the fact that C. macracanthus is a poorly known species, it is redescribed based on examination of 30 additional specimens of 105.8–162.2 mm SL, collected from Puri, Odisha, north-east coast of India (Bay of Bengal) from 2017–2019, using morphological and molecular examinations. Our study provides a detailed morphological description, first colour photographs and phylogenetic analysis using COI barcodes of the species. The study has expanded the range in several morpho-meristic characters in comparison with the type and non-type specimens described earlier. The species in fresh condition can be easily distinguished from its two congeners (C. crenidens and C. indicus) by the yellowish tip of the lower caudal-fin lobe. Our study has also extended the distribution range of C. indicus (previously known only from the north-eastern Arabian Sea) to the eastern Indian Ocean, based on examination of a preserved specimen collected from Tuticorin, Tamil Nadu.

中文翻译：

---

Crenidens macracanthus Günther 的重新描述和分子特征，1874 年（双鱼座：Sparidae），以及 1873 年在东印度洋的 C. indicus 日的首次记录

大棘蟹最初是在 1874 年根据从印度东南海岸的钦奈（马德拉斯）采集的单个标本进行描述的。1875 年，该物种被同义为C. indicus没有引用任何正当理由。从那时起，没有尝试对该属进行分类学研究克雷尼登斯，除了 2013 年，该物种从同义词中复活，并根据正模标本和非标本标本重新描述为有效物种。鉴于C. macracanthus是一个鲜为人知的物种，它是根据对 2017-2019 年从印度东北海岸（孟加拉湾）奥里萨邦普里收集的 30 个 105.8-162.2 毫米 SL 的额外标本进行重新描述的，使用形态学和分子学检查. 我们的研究使用物种的 COI 条形码提供了详细的形态描述、第一张彩色照片和系统发育分析。与前面描述的类型和非类型标本相比，这项研究扩大了几个形态特征特征的范围。新鲜条件下的物种可以很容易地与其两个同系物区分开来（C. crenidens和C. indicus) 下尾鳍叶的淡黄色尖端。我们的研究还扩大了C. indicus（以前只知道从东北阿拉伯海）到东印度洋，基于对从泰米尔纳德邦杜蒂戈林收集的保存标本的检查。