. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 05 06 08 09 (Aged Dopamme] x 10 ^ (M) Figure 5. Frequencies of velar loss after 7-h exposure to varying concentrations of aged dopamine solutions. Triangles and circles represent two assays conducted in triplicate on two different batches of larvae. Each symbol represents a trial involving 53-220 larvae. Lines connect grand means of velar loss at each concentration, calculated from arcsine transformed data. loss and were generally indistinguishable in morphology and behavior from untreated animals. Larvae
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 05 06 08 09 (Aged Dopamme] x 10 ^ (M) Figure 5. Frequencies of velar loss after 7-h exposure to varying concentrations of aged dopamine solutions. Triangles and circles represent two assays conducted in triplicate on two different batches of larvae. Each symbol represents a trial involving 53-220 larvae. Lines connect grand means of velar loss at each concentration, calculated from arcsine transformed data. loss and were generally indistinguishable in morphology and behavior from untreated animals. Larvae exposed to a higher concentration of fresh DA (2 X 1(T4 M) according to this protocol did sometimes metamorphose completely by the time the experiment was scored, but at low fre- quency (, typically .10-. 15). as suggested by earlier experiments conducted without solution replacement (Hadfield, 1984). However, in the current work, we used 1CT4 M DA for the aged versus fresh comparison because aged solutions at higher concentrations proved somewhat toxic under these conditions. Complete metamorphosis was observed at very low frequency (<.05) after exposure to fresh 1(T4MDA. The frequency of velar loss in response to varying con- centrations of aged DA is given in Figure 5. Concentration threshold for velar loss after 7-h exposure to fresh DA appears to lie between .25 and .5 X 10~4 M. Experiments to test morphogenic effects of other cat- echol compounds yielded similar results (Fig. 6). Aged solutions of the deaminated catecholamine metabolites DOPAC or DOM A (both 2 X 1(T4 A/) as well as of DOB (10~4 M) consistently yielded high frequencies of velar loss. Fresh solutions of DOPAC and DOMA were rela- tively ineffective. Fresh DOB caused most larvae to show some evidence of velar loss, but this was invariably con- fined to the loss of a few large ciliated cells at the velar margin. Aged DOB, in contrast, nearly always resulted in detachment of all the ciliated velar cell
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
