Interactions Between Small Sciaphilous Scleractinians and Epizoans in the Northern Mediterranean, With Particular Reference to Bryozoans |
| |
| Authors: | Jean-Georges Harmelin |
| |
| Institution: | Centre d.Occanologie de Marscillc, Station Marinc dEndoumc. F-13007 Marscille, France. |
| |
| Abstract: | Abstract. Two small sclcractinians, Lepfopsummiu pruvoti (solitary) and Hoplungiu dur-olrix (colonial, aggrcgatcd or not), which arc common pcrcnnial componcnts of Mcditcrrancan submarinc cavcs and dccp vcrtical walls, bcar many cpibionts on thc lowcr part of thcir corallitcs. Samplcs were collectcd ncar Marscillcs (7–58 in) undcr various cnvironmcntal conditions and coral densitics. Frequency of occurrencc of thc major cpizoan groups and of individual bryozoan spccics overgrowing the corallites varies according to habitat charactcristics and to acccssibility of the individual corallitcs for adjaccnt epizoans. Thc most frcqucnt colonizcrs arc: bryozoans (by vcgctative growth and larval settlcrnent), sponges (mainly by vcgctativc growth), and scrpulids. Among the 40 recorded bryozoan species (26 on Leptopsammia, 28 on Hoplangiu), 15 spccics are relatively frequent on each host. Comparisons of data from the corallites with thosc obtained from adjoining samples indicatc the preference for coral substratc of Pucflina radiata. This encrusting bryozoan is highly predominant on both Leptopsammia and Hoplangiu as well as on other scleractinian species. SEM observations show that overgrowth processcs are reversible and that corals may control the invading encruSters by embedding them in their sclerenchyme. The balance and benefits of this epizoan/host system are discussed. |
| |
| Keywords: | Scleractinians bryozoans spongcs cpibiosis rocky bottoms Mcditcrrancan Sea |
|
|
