. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LARVAL STAGES OF L. DORSALIS 295. FIGURE 9. Lithotrya dorsalis. SEM Posterior lateral view of cyprid carapace (A) and cuticular struc- tures: Seta (B). pore (C) and papillae (D). (Scale bars: A = 50 ^m; B = 10 ^m; C and D = 1. more elaborate, was avoided. In an attempt to increase the cyprid yield, while keeping the logistics of culture maintenance at a minimum, initial densities were increased from 1 or 2 to 6 or 8 nauplii per ml culture medium. Some of these high density cultures reached stage IV nauplius with no apparent
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LARVAL STAGES OF L. DORSALIS 295. FIGURE 9. Lithotrya dorsalis. SEM Posterior lateral view of cyprid carapace (A) and cuticular struc- tures: Seta (B). pore (C) and papillae (D). (Scale bars: A = 50 ^m; B = 10 ^m; C and D = 1. more elaborate, was avoided. In an attempt to increase the cyprid yield, while keeping the logistics of culture maintenance at a minimum, initial densities were increased from 1 or 2 to 6 or 8 nauplii per ml culture medium. Some of these high density cultures reached stage IV nauplius with no apparent deleterious effects. At this time, however, the algae being used as food (Thalassiosirafluviatilus/Tetraselmis suecicd) became contaminated. By the time a new diet was selected (Chaetoceros gracilis/ Isochrysis sp.), most cultures had been without food for 36 h. This apparent starva- tion resulted in substantial mortality, especially in older cultures. Younger cultures survived somewhat better, perhaps due to yolky material still present in these early naupliar stages. Because of the unexpected mortality, it was impossible to compare survivorship between low and high density cultures statistically. However, even though percent survival to the cyprid stage was lower in the "higher density" cultures, it was encouraging that actual cyprid yields in these cultures were higher than in the "low density" cultures. Suspecting the possible release of chemical cues, several unsuccessful attempts to initiate metamorphosis of stage VI nauplius to the cyprid stage were made by placing stage VI nauplii in "conditioned" culture medium where metamorphosis had pre- viously taken place. The size of gravid individuals at the time of sampling (September and October) was small; their carinal-rostral axes averaged mm. The larger individuals sampled at this time (carinal-rostral axes as large as mm) were not gravid. This may have. Please note that these images ar
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
