. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 90 PAMELA ROE = 898515606059397043 86819137 301540 51 25 1 1 1 1 — Estimated total number / m o — Avg. number/m all transects,at low tides Avg. number/ m2 in permanently marked areas, at low tides. Jun. JASONDJFMAMJJA 0 N D Mar Jun 968 1969 1970 FIGURE 4. Mean densities (number/m2) of Parauciucrtcs pcrct/riua at Garrison Bay. A) shows fall recruitment of juveniles from eggs spawned the previous spring; B) major mortal- ity period of adults; C) spring recruitment of juveniles from eggs spawned the previous fall; and D) low de
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 90 PAMELA ROE = 898515606059397043 86819137 301540 51 25 1 1 1 1 — Estimated total number / m o — Avg. number/m all transects,at low tides Avg. number/ m2 in permanently marked areas, at low tides. Jun. JASONDJFMAMJJA 0 N D Mar Jun 968 1969 1970 FIGURE 4. Mean densities (number/m2) of Parauciucrtcs pcrct/riua at Garrison Bay. A) shows fall recruitment of juveniles from eggs spawned the previous spring; B) major mortal- ity period of adults; C) spring recruitment of juveniles from eggs spawned the previous fall; and D) low densities due to animals staying under the mud surface, not mortality. Vertical lines along dashed line are ± one standard error from the mean. N is the number of 1 m' quadrats in which Panincincrtcs numbers were counted. Estimates of total density were cal- culated only for September 1968 to March 1969. remembered during consideration of density information. At Edmonds only the numbers of active worms were counted (Roe, 1971). At Garrison Bay (Fig. 4) and at Snug Harbor to some extent (Fig. 5) den- sities were highest in late summer and in fall, when both adults of the previous year and recruits from the previous spring or summer spawning seasons were pres- ent. Adults die in late winter (Fig. 3) reducing densities (Figs. 4. 5). but winter recruits add slightlv to the populations then (Fig. 1A, B, small individuals seen in !>ring). At this time there is also replacement of the adult population by the ••^ent year's recruits, themselves reaching adult size (Fig. 1A. B). Spring and summer are the most stable periods within each year with respect 'jiisity (Fig. 4) ; populations consists mainly of a one-year class (Fig. 5) and there ; little mortality then. At Edmonds, such patterns were not determined. The number of active nemerteans depends strongly on weather conditions. Den- sity measures in this higher intertidal area fluctuated too much for patterns to be. Please no
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
