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Abstract The Bering Strait marks the northern species boundary for blue king crabs (Paralithodes platypus), but the life history of the population at this latitude has never been described in scientific literature. Blue king crabs were collected in shallow (10-23 m) waters near King Island (n: males ?=? 199; females ?=? 260) in July of 2005 and from near Little Diomede Island (n: males ?=? 40; females ?=? 19) in April of 2007 for morphometric, fecundity and hatch timing information. Crabs from Little Diomede and King Islands showed no significant difference in male carapace length (CL) by location and were smaller than blue king crabs from more southern parts of the state (mean CL ± SE: 108.45 ± 0.70 mm). Females from King Island (mean CL ± SE: 99.47 ± 0.52 mm) were significantly larger than female crabs collected from Little Diomede Island (mean CL ± SE: 93.11 ± 2.96 mm) and male crabs (mean CL ± SE: King ?=? 107.98 ± 0.73; Diomede ?=? 110.13 ± 2.24) were significantly larger than female crabs at both locations. Weight of female crabs (mean ± SE: 810.0 ± 61.9 g) increased with CL according to a non-linear function; Crab weight ?=? 0.00165*(CL)2.8995 (r 2 ?=? 0.86). Fecundity estimates based egg counts (mean ± SE: 62,955.6 ± 4981.2) were slightly higher than visual estimates of hatched larvae (mean ± SE: 56,570 ± 6690). Timing of larval release differed significantly between female crabs held in the laboratory for 1 and 13 months. Crabs held for 1 month began hatching in mid-May 2008 with more larvae released per day and over a shorter duration (12 d). Crabs held for 13 month released fewer larvae per day over a longer duration (20 d) starting in mid-February 2009. Long-term laboratory holding may impact hatch timing due to differences in ambient temperature and perhaps other suppressed seasonal effects of the artificial environment.

The efficacy of oxytetracycline was assessed as a potential therapy for male reproductive tract syndrome in a population of 160 previously affected, pond-reared, adult Penaeus vannamei. All animals were individually tagged, and the severity of disease was assessed grossly 2 weeks before, during, and 4 weeks after feed medicated with oxytetracycline hydrochloride was administered. Bacterial cultures indicated that more Vibriosp. were isolated from animals with melanized spermatophores than from animals with normal spermatophores at the same site. Vibrio alginolyticuswas the most common bacterial isolate, and the bacterial isolates were sensitive to oxytetracycline. A t-test analysis of the mean lesion severity scores showed no significant difference between the control animals and animals that received the medicated feed. A significant difference in severity scores among designated severity groups (low, medium, high; P < 0.01) was maintained throughout the experiment. Overall, the trend in all severity groups was a gradual increase in severity over time. These results suggest that this case of male reproductive tract syndrome was not responsive to oxytetracycline therapy. In addition, these results provide further evidence of a noninfectious primary etiology.