A new species of a rarely encountered genus Sclerobregma Hartman, 1965 (Annelida, Scalibregmatidae) from the deep South China Sea

In the present study, a new species of a rarely encountered genus <i>Sclerobregma</i> Hartman, 1965, <i>Sclerobregmananhaiensis</i> <b>sp. nov.</b>, is described based on specimens collected from slope depths of the northern South China Sea. It is characterized by the presence of branched branchiae and heavy acicular spines in the anterior chaetigers, and is morphologically distinct from the other species of the genus in the shape of the anterior margin of the prostomium, the number of neuropodia with nipple-like projections distally, and the segment annulation. Four gene fragments of the new species were sequenced, comprising 16S rRNA, 18S rRNA, 28S rRNA, and histone H3. This study represents the first report of <i>Sclerobregma</i> in the South China Sea.