. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PATTHRNS AND PROCESSES OF LARVAL EMERGENCE 115 Table 3 viiriiitiim in iliiriitinn Source /•-\alue ' i nl variation ill P explained Time 1/19 <()()l Time ol iinoiuhl 11(13 1/19 < Temperature <)1 1/19 ( < Salinil\ 1/19 Laboratory experiments Hn-,1 inundation. Throughout all laboratory studies, cer- cariae emerged onl\ if snails were totally submerged. The average number of cercariae to emerge in paired treatments with submerged (3861 ± 599 SEM) and d
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PATTHRNS AND PROCESSES OF LARVAL EMERGENCE 115 Table 3 viiriiitiim in iliiriitinn Source /•-\alue ' i nl variation ill P explained Time 1/19 <()()l Time ol iinoiuhl 11(13 1/19 < Temperature <)1 1/19 ( < Salinil\ 1/19 Laboratory experiments Hn-,1 inundation. Throughout all laboratory studies, cer- cariae emerged onl\ if snails were totally submerged. The average number of cercariae to emerge in paired treatments with submerged (3861 ± 599 SEM) and dry (0 ± 0 SEM) snails showed unequivocally that cercariae would not leave the host unless it was underwater (Student's / test: / = df = 5, P < ). The muddy channel containing the highest snail densities was at a tidal height of about 250 e 00 u W 200- 100 - 50- 3 *. B 10 12 14 16 18 20 '—' ' Zi "J ^ y "3 -^ O £ Ef- -= ua H 10 12 14 16 Time of Day (h) 18 20 Figure 3. Effect of time of day (TOD) on cercarial emergence duration in the tield. (A) The amount of time for 95% of all cercariae to emerge during a given event (4 h) as a function of TOD. (B) The total number of cercariae emerged per snail during a given event as a function of TOD. 9:00 n a c C/3 I •g Of) 8 'i § u ^-i O I z n .Illn 12:00 1 15:00 1 0 n h • 18:00 IL 9 edana and P. acanthus began in 15 °C water and continued for the maximal temperature (19 °C) tested. Renicola huclianani emerged at an intermediate threshold of 17 °C through 19 °C. The two warm-water species, E. californensis and Microphallid vacated their hosts only in the warmest waters tested (18-19 °C). Two- way nested ANOVAs were performed for each species separately. The numbers of emerged cercariae were signif- icantly different among temperatures (P < for all species) and individual snails (P ) effect on the outcome. S
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
