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Vol. 53 - Alaska Resources Library and Information Services

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June 1978 compared to June 1981. Contrasting P. tridens with P.<br />

borealis larval development (Figs. 6.3 <strong>and</strong> 6.4), P. tridens larvae were<br />

generally one stage or one molt behind P. borealis larvae by June of<br />

both years. For example, in June 1978, 60% of P borealis larvae were<br />

SIV or greater compared to 46% of P. tridens larvae, while in June 1981,<br />

93% of P. borealis larvae were SIV or greater versus 54% of P. tridens<br />

larvae.<br />

The northernmost extent of the range of P. stenolepis is given by<br />

Butler (1980) as Unalaska Isl<strong>and</strong>. The NOAA 1977 cruise first took P.<br />

stenolepis SI in mid-April just west of Unimak Pass. No other cruises<br />

sampled this area during April. All other cruises took SI zoeae from<br />

mid-May until early June. The frequency of P. stenolepis occurrence was<br />

so low it is not possible to make definitive statements regarding this<br />

long SI duration (except possibly asynchronous hatch-out within the<br />

population). Figure 6.2 shows duration of stages from April until July<br />

for PROBES 1981. Since early sampling was not done near Unimak Pass,<br />

first hatch-out <strong>and</strong> the duration of SI <strong>and</strong> SII is not well-documented.<br />

Sampling in May <strong>and</strong> June over central St. George Basin took later S of<br />

P. stenolepis (II-VI), but no megalopae were found. With respect to<br />

staging, P. stenolepis larvae were mostly stages I <strong>and</strong> II during late<br />

April-early May (NOAA 1977), stages III <strong>and</strong> IV during early-mid June<br />

(PROBES 1981), <strong>and</strong> stages IV <strong>and</strong> V from late June to early July. These<br />

larvae would probably not complete metamorphosis before late August.<br />

P<strong>and</strong>alus goniurus adults are commonly taken from the St. George<br />

Basin (Feder 1978) in the 38-124 m depths on a mud to coarse s<strong>and</strong><br />

719

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