Vol. 53 - Alaska Resources Library and Information Services

7.2.1 Larval Duration
Although several stage I pagurid larvae were found in early March
(NOAA 1978) indicating a hatchout period of late February to early March
for at least 1 pagurid species, high densities of pagurid larvae were
not found until April (Fig. 7.2) indicating a mid to late March hatchout
period for the majority of pagurid species.
During 1981, some stage I
pagurid larvae were still present as late as July (Table 7.2 and Fig.
7.1) illustrating the asynchronous hatchout periods and possibly multiple
brood strategies of species in the pagurid group.
Pagurid larvae were not identified to species but were separated
into individual zoeal (I-IV) and megalops stages.
Densities were calculated
for each individual larval stage.
Average densities for each
month (1981) were used to examine the relative frequency of occurrence
of various larval stages.
However, molt frequency is somewhat difficult
to gauge from present data since numerous pagurid species are grouped
together.
A larval stage frequency histogram for PROBES 1981 (Fig. 7.1) shows
the basic developmental trend among the pagurids from April to July.
In
April and May a majority of the pagurids are SI, by June SIII, and by
July SIV with a small percentage of pagurids reaching the megalops
stage.
The intermolt period for pagurids must be 3-4 weeks between
stages and thus total duration of planktonic life would approach 3.5-4.0
months from April-August for most species.
782