Affiliation:
1. Marine Zoology Department Senckenberg Research Institute and Natural History Museum Frankfurt Germany
2. Bonn Institute of Organismic Biology (BIOB), Sec. II Animal Biodiversity University of Bonn Bonn Germany
3. Whitney Laboratory for Marine Bioscience University of Florida St. Augustine Florida USA
Abstract
AbstractChaetae are among the most extensively studied structures in polychaetes, serving as a defining morphological trait for annelids. Capitella teleta stands out as one of the few established annelid models for developmental and morphological studies, thus receiving significant scholarly attention. In this study, we unveil a previously unnoticed glandular structure associated with chaetae within the larvae of C. teleta. Our investigations demonstrate the absence of comparable structures in the chaetal follicles of adults and juveniles (older than 1 week), as well as during active chaetogenesis, underscoring the transient nature of these glands. This indicates that larval chaetal follicles transform into a gland that later disappears. Utilizing histology and transmission electron microscopy, we characterized these glands. Our findings underscore the diversity of chaetal ultrastructure in annelids and show that, even in well‐studied species, novel morphological details can be found. We emphasize the importance of examining various life‐history stages to capture such transient morphological features. This work lays a crucial morphological foundation and deepens our understanding of chaetae and chaetogenesis in C. teleta, paving the way for more accurate interpretations of future experimental studies on chaetogenesis in this species.