The life histories of two common boreal-Arctic bryozoans – Electra pilosa and Callopora craticula – living on kelps in the White Sea are described for the first time using colony mapping. Colony functional dynamics (sexual, feeding, budding and rejuvenation) was traced seasonally via recording zooidal states. During the ice-free season the population of the broadcaster E. pilosa is represented by three generations – overwintered (maternal) and two summer ones (daughter and granddaughter). The overwintered colonies exhibit two-phased reproduction and the ‘early’ daughter colonies reproduce just once. ‘Late’ colonies, together with the granddaughter generation, remain sterile, accumulating nutrients for overwintering. Four generations are described for the brooder C. craticula, three of which continuously produce larvae. While the two species co-exist on the same substrate, reproduction in E. pilosa starts almost one month later (in late June), that could be explained by the insufficient abundance of phytoplankton in early summer to support the start of oogenesis and feeding cyphonautes larvae. The estimated maximal colony lifespan is 13 months in E. pilosa and 15 months in C. craticula. The broad comparison of bryozoan reproductive ecology in the White Sea showed that their life histories are much more diverse, complex and evolutionarily flexible than previously acknowledged.
|Журнал||Invertebrate Reproduction and Development|
|Ранняя дата в режиме онлайн||27 фев 2020|
|Состояние||Электронная публикация перед печатью - 27 фев 2020|
Предметные области Scopus
- Зоология и животноводство