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Vol. 53 - Alaska Resources Library and Information Services

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3.1.2 Reproduction<br />

In late winter <strong>and</strong> early spring adult males apparently migrate from<br />

deeper, offshore areas to join females in shallow water for breeding<br />

around Kodiak Isl<strong>and</strong> (Powell et al. 1974; Weber 1967; NOAA 1981; it is<br />

not known if such migratory behavior exists in the southeastern Bering<br />

Sea). Eggs carried from the previous year hatch about April 1-20<br />

(Haynes 1974; Weber 1967) <strong>and</strong> females soon undergo physiological changes<br />

leading to molt.<br />

By pheromone attraction (NOAA 1981) sexually mature<br />

males locate preecdysial females, embrace them for as long as 16 days,<br />

<strong>and</strong> mate just after the female molts (Powell et al. 1974).<br />

The nearshore,<br />

shallow water habitat is apparently selected in part for warmer<br />

water temperatures (<strong>and</strong> perhaps greater food supplies).<br />

The average<br />

temperature inhabited by sexually mature males <strong>and</strong> females is 1.5° <strong>and</strong><br />

4°C, respectively; (NOAA 1981).<br />

Stinson (1975) correlated male <strong>and</strong> female<br />

abundance with temperature <strong>and</strong>, from NMFS survey data through 1975,<br />

located most sexually mature females inside a 4°C isotherm nearshore off<br />

Unimak Isl<strong>and</strong> <strong>and</strong> directly in front of Port Moller. Weber (1967)<br />

summarized data on temperature-related hatchout time <strong>and</strong> development,<br />

noting both regional <strong>and</strong> annual differences in larval appearance <strong>and</strong><br />

rate of development attributable to temperature variations.<br />

Larval<br />

development time can double with a decrease of temperature from 10° to<br />

5°C (Kurata 1960, 1961), <strong>and</strong> an average of 460 degree days (= cumulative<br />

average daily temperature from hatch of egg to metamorphosis of megalops)<br />

is required for the species (Kurata 1961).<br />

After molting a female must be located <strong>and</strong> mated within 5 days for<br />

viable eggs to be produced (possible impact of oil on chemosensory<br />

<strong>53</strong>9

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