Morphology Characterization of Anterior Regeneration in <em>Diopatra claparedii</em>

Polychaetes possess the ability to regenerate anterior and posterior segments following injury or self-amputation, offering a tractable system for studying wound repair and tissue patterning. To support comparative and mechanistic studies in annelid regeneration, this study presents a protocol for inducing and characterizing anterior regeneration in Diopatra claparedii (D. claparedii). The protocol outlines steps for specimen handling, immobilisation, and precise amputation, followed by scheduled observational time points to document morphological progression throughout regeneration. D. claparedii were gently removed from their tubes using a blunt-ended stick and immobilised in 4% magnesium chloride to induce relaxation. Anterior amputation was performed at the 4th chaetiger under a stereomicroscope, and the regeneration process was monitored on days 1, 6, 15, 30, and 60 post-amputation. The procedure enables consistent induction of anterior regeneration and captures key morphological features across early wound closure, blastema formation, and segment re-establishment. By providing a reproducible workflow and morphological reference for D. claparedii, this protocol offers a practical foundation that supports future investigations that aim to relate morphological observations to underlying cellular or molecular processes in annelid regeneration.