A Quantitative Study of Reproduction in Some Species of Ceriodaphnia (Crustacea: Cladocera)

Abstract

All rights reserved INFO RM ATIO N TO ALL USERSThe quality of this reproduction is dependent upon the quality of the copy submitted.In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Relationship between egg number and body length. ^i.Relationship of egg volume to body length. 36.Egg number, body length, temperature, and chlorophyll. 41»The shape of Ceriodaphnia eggs in relation to their volume. * Egg size and temperature. 50«The seasonal occurence of sterile eggs in I9 6 3 . 50.The Maltese species. 3 ,'Discussion. 5 4 .Acknowledgements. gp. Summary. 5X.Bibliography. 5Âppendices. ^2 An important fact brought out by these graphs is the difference in size of these species. Ceriodaphnia reticulata is consistently larger, on average, than C. pulchella and C. megalops is larger than either of these two species.C. laticaudata overlaps between C. reticulata and C. pulchella.There is some overlap in the sizes of all four species when one considers the full range measured, as in Table 2. (Table 3») that the larger eggs approximate most nearly to a sphere.There is a negative correlation coefficient of -0.^7, which, with 8l degrees of freedom has p<T0.001.As can be seen from Table 5 At any particular temperature in I963 the mean body length of Geriodaphnia pulchella was less than that of G . reticulata (Fig 8).In both species body length decreased with increasing temperature. Mean egg number increased with mean body length at the same rate in both species (Fig. 3) but when mean egg numbers were corrected to the grand mean

Successional Changes, Variations in Population Densities, and Reproductive Strategies of Cladocera in Two Temporary Ponds in North Alabama

“…1). Daphnia magna is sensitive to crowding and environmental change, while D, puler is tolerant (Smith 1963, ~utchinson 1967, Burgis 1967. In a similar situation D. puler eliminated C. megalops from WEUP Pond (Fig.…”

“…Additionally, the feeding strategy of C. laticaudata is known to differ from that of D. puler (Hutchinson 1967). Neither species appears to compete with D. pulex and all are capable of living under adverse environmental conditions (Hutchinson 1967, Burgis 1967. The gradual increase during the winter in the size of the D. pulex and D. m a w populations and the occurrence in these species of a large number of parthenogenetic broods suggested that their reproductive efforts were directed toward the production of subitaneous eggs (Table 1).…”

Body length, size of resting eggs and identification of the ephippia of Ceriodaphnia megalops and Ceriodaphnia pulchella

“…For both egg types, the eg^ of C. megalops are approximately twice the volume of the eggs of C. pulchella (Tables 1 and 4). Burgis (1967) found that the volume of a clutch of parthenogenetic eggs increased directly to body length in both species. Such a relationship does not apply to their resting eggs; the volume of a resting egg being independent of maternal body length in each species.…”

“…Synopsis of data given by Burgis (1967) for Ceriodaphnia megalops and Ceriodaphnia pulchella. All data refer to parthenogenetic females (Burgis, 1967). / = egg length; w = egg width.…”

Temperature responses of Ceriodaphnia quadrangula (O.F. Müller, 1785) (Anomopoda) from the littoral of the Rybinsk Reservoir

“…It was noted in some reports that the temperatures within the range of 15.0-25.0°C positively affect the growth and reproduction in C. quadrangula [9,13,14,28]. According to some reports [22] temperatures within the range of 16.0-20.0°C are optimal; according to others [24] the opti mal range is 17.0-23.0°C.…”