. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ASCIDIAN-ALGAL LARVAL ECOLOGY 229 gives a mean time of release of 12:54 (SE : minutes). The data do not differ significantly from a normal distribution [Kolmogorov-Smirnoff, dmax = , P > (Sokal and Rohlf, 1969)]. The symbiotic algae of D. molle are extracellular to the animal host. In an adult colony, the algae line the walls of the common cloaca. In a larva, the algae are attached to small hairlike projections at the posterior end of the larval body (Kott, 1980). Although no data exist on the physiological
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ASCIDIAN-ALGAL LARVAL ECOLOGY 229 gives a mean time of release of 12:54 (SE : minutes). The data do not differ significantly from a normal distribution [Kolmogorov-Smirnoff, dmax = , P > (Sokal and Rohlf, 1969)]. The symbiotic algae of D. molle are extracellular to the animal host. In an adult colony, the algae line the walls of the common cloaca. In a larva, the algae are attached to small hairlike projections at the posterior end of the larval body (Kott, 1980). Although no data exist on the physiological importance of the algae to the larva, it is doubtful that they contribute much to the larva's nutrition, considering their external location. Photoadaptations of the algae The ratio of chlorophyll a to chlorophyll b is generally regarded as a relative indicator of the light levels to which a plant is photoadapted (Boardman, 1977). Chlorophyll b is an accessory photosynthetic pigment, absorbing light primarily around 470 nm and 650 nm. It is usually produced in higher quantities in lower light environments. This appears to hold true for the D. molle colonies analyzed (Fig. 5). Adult colonies living deeper have greater amounts of chlorophyll b relative to chlorophyll a. However, examination of larvae collected from shallow water colonies (2 m depth) shows that their chl a/chl b ratio is less than that of their parent colonies. The larvae thus appear to be photoadapted to lower light regimes than the habitat of the parent colonies. How can the larval algae have a lower chl a/chl b ratio than the parent from which it was released? Although current research suggests that some phytoplankton can alter their chlorophyll ratio in very short periods of time (Falkowski, 1980), it is doubtful that this is the case for D. molle larvae since they have such a brief swimming period and are exposed to a wide range of light intensities. The values presented in Figure 5 represent averages for ext
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
