Intraspecific fusion in the encrusting bryozoan Fenestrulina sp.
Craig, S.F. (1994). Intraspecific fusion in the encrusting bryozoan Fenestrulina sp., in: Hayward, P.J. et al. (Ed.) Biology and Palaeobiology of Bryozoans: Proceedings of the 9th International Bryozoology Conference, School of Biological Sciences, University of Wales, Swansea, 1992. International Symposium Series, 9: pp. 51-54
In: Hayward, P.J.; Ryland, J.S.; Taylor, P.D. (Ed.) (1994). Biology and palaeobiology of bryozoans: Proceedings of the 9th International Bryozoology Conference, School of Biological Sciences, University of Wales, Swansea, 1992. International Symposium Series, 9. Olsen & Olsen: Fredensborg. ISBN 87-85215-23-6. VIII, 240 pp., more
In: International Symposium Series. Olsen & Olsen: Fredensborg, more
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| Keywords |
Intraspecific relationships
Bryozoa [WoRMS]; Fenestrulina Jullien, 1888 [WoRMS]
Marine/Coastal |
| Abstract |
The marine bryozoan Fenestrulina sp. heavily encrusts blades of the kelp Agarum cribrosum (Bory) in the Damariscotta Estuary, near Walpole, Maine. Intraspecific contact led to skeletal fusion in 19 out of 27 paired colonies (70%) followed on four artificial settlement plates for a period of two weeks. Evidence for skeletal fusion came from two sources: 1) daily photographs revealed that both colonies produced peripheral buds, which contacted each other and coalesced to form a single, irregularly-shaped zooid, and 2) scanning electron micrographs revealed the presence of pores in the skeletal walls between fused colonies. Normally these pores are found within colonies, and allow nutrient translocation (via the funiculus) between zooids. Their presence between colonies strongly suggests that fused colonies are physiologically integrated. If close genetic relatedness is required for skeletal fusion, then either Fenestrulina larvae have a remarkable ability to settle next to relatives, or very little genetic variation exists within the population. Alternatively, skeletal fusion in Fenestrulina may not depend on genetic relatedness, in which case overgrowth reactions may represent cases where colonies fail to distinguish conspecifics from heterospecifics. |
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