Vol. 53 - Alaska Resources Library and Information Services

Six time intervals were established to study larval hatch and
development (Fig. 3.17a and b).
They are based on average sampling
dates of cruise legs in various years, and usually span three-week
intervals.
The earliest zooplankton samples collected that contained
red king crab larvae were prior to April 18 in 1977; the latest
collections were made in August, 1982. Based on data from 1977 and
1978, SI larvae were abundant by mid-April and SII by late April, 1978
(Fig. 3.17a).
In some years, therefore, larvae hatch as early as April
1 (note that 40% of all larvae were already SII in late April 1978). In
other years hatching can begin a month or more later. In mid-May, 1976,
virtually all larvae were still SI and in early June, 1980, 40% of
larvae were SI. (During the first NAS leg from April 18 to May 7, 1983,
no larvae were found along the entire NAS from Unimak Island to Port
Heiden on the first pass.
Larvae were present on the return, however,
at stations revisited between May 1-6, indicating hatch began about May
1). The largest interannual difference in apparent time of hatch was
between the years 1976 and 1979 (Fig. 3.17a) when all larvae were SI in
mid-May, 1976, but all were SIV in mid-June, 1979, indicating a very
late and early hatch, respectively.
Larval hatch is apparently not a synchronous event throughout the
female population along the NAS as evidenced by the presence of several
larval stages at most stations (Fig. 3.17a and b). Data of 1980, 1981,
and 1982 show that four larval stages were present in the water column
during several time intervals, although only two stages were usually
dominate (Fig. 3.17b).
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