TY - JOUR

T1 - Electra vs Callopora

T2 - life histories of two bryozoans with contrasting reproductive strategies in the White Sea

AU - Shevchenko, Ekaterina T.

AU - Varfolomeeva, Marina A.

AU - Nekliudova, Uliana A.

AU - Kotenko, Olga N.

AU - Usov, Nikolay V.

AU - Granovitch, Andrei I.

AU - Ostrovsky, Andrew N.

N1 - Funding Information: This work was supported by the Russian Science Foundation [grant 18-14-00086 (microscopy and statistical analysis)];?Saint Petersburg State University [grant 1.38.233.2015 and 1.42.1493.2015 (field collecting and material processing)];?and the Russian Foundation for Basic Research [grant 16-04-00243-a (histological work)]. This study was performed using the laboratories and equipment of the Educational and Research Station ?Belomorskaia? and the Centre for Molecular and Cell Technologies, Saint Petersburg State University. Mr A.A. Miroliubov, Zoological Institute, Russian Academy of Sciences, Saint Petersburg, kindly collected material under ice. We thank Dr M. Stachowitsch, University of Vienna, who revised an early draft of the manuscript and improved its English. We are also deeply indebted to two anonymous reviewers, whose constructive criticism and advice helped to improve the manuscript.

PY - 2020/4/2

Y1 - 2020/4/2

N2 - 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 zygote spawner E. pilosa was represented by three generations–overwintered (maternal) and two young ones (daughter and granddaughter). The overwintered colonies exhibited two-phased reproduction and the ‘early’ daughter colonies reproduced just once. ‘Late’ colonies, together with the granddaughter generation, remained sterile. Four generations are described for the brooder C. craticula, three of which continuously produced larvae. While the two species co-exist on the same substratum, reproduction in E. pilosa started almost 1 month later (in late June), which 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.

AB - 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 zygote spawner E. pilosa was represented by three generations–overwintered (maternal) and two young ones (daughter and granddaughter). The overwintered colonies exhibited two-phased reproduction and the ‘early’ daughter colonies reproduced just once. ‘Late’ colonies, together with the granddaughter generation, remained sterile. Four generations are described for the brooder C. craticula, three of which continuously produced larvae. While the two species co-exist on the same substratum, reproduction in E. pilosa started almost 1 month later (in late June), which 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.

KW - Aquatic colonial invertebrates

KW - sexual reproduction

KW - Bryozoa

KW - CELLEPORELLA-HYALINA BRYOZOA

KW - HISPIDA FABRICIUS

KW - PATTERNS

KW - SEXUAL REPRODUCTION

KW - EVOLUTION

KW - ECOLOGY

KW - GYMNOLAEMATA

KW - CHEILOSTOMATA

KW - PROPAGATION

KW - CRIBRILINA-ANNULATA

UR - http://www.scopus.com/inward/record.url?scp=85080138344&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/89dd4bfc-bc39-388f-a952-0e954347098c/

U2 - 10.1080/07924259.2020.1729260

DO - 10.1080/07924259.2020.1729260

M3 - Article

AN - SCOPUS:85080138344

VL - 64

SP - 137

EP - 157

JO - Invertebrate Reproduction and Development

JF - Invertebrate Reproduction and Development

SN - 0792-4259

IS - 2

ER -