Frontiers in Zoology volume 17 , Article number: 19 Cite this article. Metrics details. Ascidians phylum Chordata, class Ascidiacea represent the closest living invertebrate relatives of the vertebrates and constitute an important model for studying the evolution of chordate development. The solitary ascidian Polycarpa mytiligera exhibits a robust regeneration ability, unique among solitary chordates, thus offering a promising new model for regeneration studies.
Understanding its reproductive development and establishing land-based culturing methods is pivotal for utilizing this species for experimental studies. Its reproduction cycle, spawning behavior, and developmental processes were therefore studied in both the field and the lab, and methods were developed for its culture in both open and closed water systems.
Field surveys revealed that P. Although spontaneous spawning events occur only between June and December, we were able to induce spawning under controlled conditions year-round by means of gradual changes in the environmental conditions. Spawning events, followed by larval development and metamorphosis, took place in ascidians maintained in either artificial or natural seawater facilities.
Polycarpa mytiligera can be induced to spawn in captivity year-round, independent of the natural reproduction season. The significant advantages of P. Ascidians are marine invertebrates that constitute the closest relatives to the vertebrate subphylum [ 1 , 2 ].
They are primarily sessile, with a brief pelagic larval stage that shares the typical chordate tadpole-type features, including a pharynx with gill slits, a notochord, and a hollow nerve cord [ 3 ]. Due to their phylogenetic position, inland culturing methods, relatively short life cycle, and simple body plan, ascidians offer an important model for developmental and evolutionary studies [ 4 , 5 , 6 , 7 ].
