Decker Sebastian H, Lemer Sarah, Decker Simone, Hirose Masato, Johnson Mildred J, Schwaha Thomas
Department of Evolutionary Biology, University of Vienna, Schlachthausgasse 43, Vienna, 1030, Austria.
Marine Laboratory, UOG Station, Mangilao Guam, 96923, USA.
Zoological Lett. 2024 Jun 14;10(1):10. doi: 10.1186/s40851-024-00234-z.
As in most colonial and sessile marine invertebrates, bryozoan life history is characterized by asexual propagation of zooids for colonial growth and by sexual production of larvae for dispersal. However, comprehensive life histories, particularly in cryptic species such as endolithic (boring) bryozoans, remain poorly understood. The ctenostome family Penetrantiidae is widespread from temperate to tropical waters and often found in molluscan shells, offering an opportunity to study the boring lifestyle and its potential impact on bioerosion through growth and settlement experiments. Our research focused on Penetrantia clionoides from Guam in the Pacific Ocean, Penetrantia japonica from Japan, and a Penetrantia species from France in the Atlantic Ocean. We found distinct life histories and reproductive patterns potentially influenced by environmental factors such as temperature and food availability. The tropical P. clionoides displayed higher rates of larval production and growth compared to its temperate counterpart. For instance, the mean stolon extension was 335.2 μm/week in P. clionoides versus 232.1 μm/week in Penetrantia sp. Autozooid development took 13 days in P. clionoides and 31 days in Penetrantia sp. Anatomical features like apertural rims aided in species identification and in understanding larval settlement preferences, suggesting a tendency for philopatric settlement behavior. The bioerosional impact of penetrantiids remains little understood, but we generated first projections of bioerosion rates and a protocol for keeping Penetrantia under laboratory conditions, laying a foundation for further research in this field.
与大多数殖民性和固着性海洋无脊椎动物一样，苔藓虫的生活史特征是通过类虫体的无性繁殖实现群体生长，以及通过有性生殖产生幼虫实现扩散。然而，全面的生活史，尤其是像内生（钻孔）苔藓虫这类隐秘物种的生活史，仍然鲜为人知。栉口苔藓虫科在从温带至热带水域广泛分布，且常发现于软体动物壳中，这为通过生长和定居实验研究钻孔生活方式及其对生物侵蚀的潜在影响提供了契机。我们的研究聚焦于来自太平洋关岛的克氏苔藓虫、来自日本的日本苔藓虫以及来自大西洋法国的一种苔藓虫。我们发现了明显受温度和食物可利用性等环境因素影响的生活史和繁殖模式。与温带的同类相比，热带的克氏苔藓虫表现出更高的幼虫产量和生长速率。例如，克氏苔藓虫的平均匍匐茎延伸速率为每周335.2微米，而另一种苔藓虫为每周232.1微米。克氏苔藓虫的自虫体发育耗时13天，另一种苔藓虫则耗时31天。诸如孔缘等解剖特征有助于物种鉴定以及理解幼虫的定居偏好，这表明存在亲地定居行为的倾向。钻孔苔藓虫对生物侵蚀的影响仍知之甚少，但我们首次预测了生物侵蚀速率，并制定了在实验室条件下饲养苔藓虫的方案，为该领域的进一步研究奠定了基础。
