. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. H2S EFFECTS ON CAP1TELLA LARVAL SETTLEMENT 33 100 -i 1 o to a > s?. Time (min) Figure 1. Settlement of freshly hatched Capilella sp. I larvae in sediment. Each curve represents settle- ment times of sibling larvae from one brood; 7 broods with between 13 and 74 larvae were tested. Settle- ment was observed continuously until all larvae settled. Behavior. For these experiments the brood tubes were opened manually when the larvae began hatching (see Materials and Methods). However, there was no differ- ence in behavior betw
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. H2S EFFECTS ON CAP1TELLA LARVAL SETTLEMENT 33 100 -i 1 o to a > s?. Time (min) Figure 1. Settlement of freshly hatched Capilella sp. I larvae in sediment. Each curve represents settle- ment times of sibling larvae from one brood; 7 broods with between 13 and 74 larvae were tested. Settle- ment was observed continuously until all larvae settled. Behavior. For these experiments the brood tubes were opened manually when the larvae began hatching (see Materials and Methods). However, there was no differ- ence in behavior between these and 'naturally' hatched larvae. All larvae showed positive phototaxis, as de- scribed for this species by Butman et al. (in press). Upon leaving the brood tube, larvae immediately swam up to the surface and then toward the light sources on opposite sides of the petri dish. Larvae that settled within minutes then turned away from the light, swam down towards the mud, and crawled into it (at which point settlement time was recorded). Larvae that took longer to settle regularly swam back and forth between both light sources or clumped at the brighter light source (one ring light was inevitably a little closer than the other to the dish) before swimming down to and entering the mud. Only rarely would larvae test the mud and swim away again; larvae almost never left the mud after settling. On some occa- sions loss of cilia was observed within the next 5-10 min. In several instances where brood tubes were not torn apart, I observed a few larvae that metamorphosed within the brood tube over a period of 1-2 h. The juve- nile worms then left the tube and crawled into the mud. H2S experiments with sediment In the presence of sediment alone behavior of older larvae (up to 35 h post-hatching) was similar to that of freshly hatched larvae, while settlement was even quicker. Fifty percent settled within 1 min. 90% within 5 min, and only 3 of 150 larvae tested took longer than 30 mi
Size: 2073px × 1205px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
