. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 180 J. M. COUPER AND E. M. LEISE ent cultures were used for at least two of the repeated experiments to ensure that results were consistent and did not depend upon the culture used. Results from each experiment were pooled, and the combined results were tested for statistical significance, as described below. The graphs presented in this paper were obtained from these pooled results. Mortality was generally near zero in the bath experiments, and around 5% in the injection exper- iments. The results reported here include only
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 180 J. M. COUPER AND E. M. LEISE ent cultures were used for at least two of the repeated experiments to ensure that results were consistent and did not depend upon the culture used. Results from each experiment were pooled, and the combined results were tested for statistical significance, as described below. The graphs presented in this paper were obtained from these pooled results. Mortality was generally near zero in the bath experiments, and around 5% in the injection exper- iments. The results reported here include only surviving individuals. Usually, less than 400 larvae were available for experimentation in any particular culture. As a re- sult, in many experiments the number of larvae in the control groups was reduced to maintain sufficient num- bers of animals in the experimental treatments. This did not impair the statistical significance of the results. Inject it >n experiments Animals that attained a shell length of about 630 ^m or longer were described as competent by Scheltema (1962). In our cultures, 12-40-day-old animals measur- ing 600-625 urn were usually competent and were used for all injection experiments. Larvae that were smaller than 600 ^m showed a lower percentage of metamor- phosis in response to 5-HT or the natural inducer. Older, larger larvae (>700 j/m) were not useful for injection ex- periments as a relatively high percentage of these animals metamorphosed spontaneously and in response to FIO (control) injections. This obscured the effects of 5-HT and other experimental compounds. To facilitate access to the larval hemocoel, larval shells were decalcified by culturing the animals in a low pH and calcium-free artificial seawater bath overnight (Pires and Hadfield, 1993). Larvae were reacclimated to normal seawater (pH ) using several changes of FIO. Prior to injection, larvae were embedded in a 1% wgt/vol solution of low-melting-point agarose (Type VII. Sigma
Size: 1988px × 1256px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
