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Vol. 53 - Alaska Resources Library and Information Services

Vol. 53 - Alaska Resources Library and Information Services

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Figure 6.33, these deepwater shrimp must have a protracted hatchout<br />

period.<br />

[Late summer sampling,as taken in August 1982, will be examined<br />

for later stages (IV-VI) of this species.]<br />

Kurata (1964) described SVI<br />

<strong>and</strong> VII of a similar spiny larva, which he assigned to Glyphocrangon<br />

spp.<br />

One sample collected in October 1980 by the R/V Alpha Helix from<br />

east of the 200 m isobath contained one of these later SVI larvae.<br />

Additional late summer examples of this spiny larva may have been collected<br />

among the 1982 samples.<br />

Neither the total number of larval<br />

stages nor the total duration of planktonic larval life is known for<br />

this species.<br />

A molt frequency histogram, based on the PROBES 1981 cruises, is<br />

given in Figure 6.34 for these spiny larvae.<br />

The intermolt period seems<br />

to be about 20 days <strong>and</strong> thus (given at least 7 larval stages) these<br />

zoeae would be in the water column until the end of September or early<br />

October (as supported by the Alpha Helix collection in October 1980).<br />

Distribution <strong>and</strong> Abundance: Positive station values for all years, 1976-<br />

1981, were combined for Figure 6.35. The deep water origin (> 200 m) of<br />

these spiny penaeid larvae is evident, <strong>and</strong> maximum densities of 1000-<br />

9000 larvae/100 m² occurred in strata 7, 3, <strong>and</strong> 4 beyond the shelf<br />

break.<br />

Abundance of these larvae over the outer shelf domain of the St.<br />

George Basin was generally very low, with densities ranging from 20-200<br />

larvae/100 m 2 in strata 8, 2 <strong>and</strong> 5 except during May 1977 (NOAA) when<br />

higher densities of 200-3000 larvae/100 m 2 were taken in strata 8 <strong>and</strong> 5.<br />

Spiny larvae were rarely caught during the 1976, 1979, <strong>and</strong> 1980 cruises<br />

<strong>and</strong> were caught in very low numbers (< 500 larvae/100 m 2 ) in stratum 3<br />

768

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