. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 132 IVAN - ' a massive increase in tin- number of larvae available, with a consequent increase in the number of ascidians successfully colonizing in the populations. It will be noted that population K differs in two respects from other popula- tions. First the initial coloni/ation by SO ascidians in the first two months \vas small, and second there was a large additional colonization of 114 animals in No- vember January, 1960/61. The panels on which this population developed were first immersed in June. 1('6(), and the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 132 IVAN - ' a massive increase in tin- number of larvae available, with a consequent increase in the number of ascidians successfully colonizing in the populations. It will be noted that population K differs in two respects from other popula- tions. First the initial coloni/ation by SO ascidians in the first two months \vas small, and second there was a large additional colonization of 114 animals in No- vember January, 1960/61. The panels on which this population developed were first immersed in June. 1('6(), and the small initial settlement is in keeping with earlier findings ((ioodbodv. 1'^da) that the intensity of larval settlement is minimal at this time of the year. The high level of secondary colonization is due to the com- bined effects of the mid-winter abundance of larvae and an early retreat and frag- mentation of tlu' fiidciiinuiii community. It is usual in these communities for the />!(lciiiiniiii to be replaced by sponges immediately but, for reasons which cannot at present be explained, the /lidcinmini associated with population E retreated rather suddenly in November, 1()(>0. and was not immediately replaced by sponge. As it fragmented and retreated it left fresh surfaces available for colonization by A. nigra which established itself before the Itidcinmini grew back or was replaced. This exceptional circumstance might be considered seriously to bias the figures given in Table II and Figure 1. so that it is necessary to point out that the total picture is un- affected by the data from population E. If we re-analyze the data in Table II for .November and December, 1(>6(). and January, 1961, excluding the data for popula- tion E, we arrive at the following figures for the number of colonizers per exposed panel side: November, ; December. ; January, These figures still in- 2-Ch. 05- J FMAMJ JASONDJFMAMJJ ASONDJ FM I960 1961 1962 'KK 1. C'lilonixation l>
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
