This study compares timing of egg extrusion, embryo development, timing and duration of eclosion, and incubation periods of Kodiak, Alaska primiparous and multiparous Tanner crabs (Chionoecetes bairdi) reared in identical conditions to determine if and how these variables differ between reproductive states. Female reproductive state (primiparous or multiparous) and dates of egg extrusion were recorded, eggs were sampled monthly to determine egg stage and area, and larvae were collected daily during eclosion to determine timing and duration of eclosion.

Stock assessment of Alaskan red king crab, Paralithodes camtschaticus (Tilesius, 1815), can be improved by incorporating reproductive output, which requires an understanding of the size-fecundity relationship, interannual and seasonal variability in fecundity, and maternal size effects on embryo and larval quality. We collected red king crab egg clutches from Bristol Bay, Alaska, in summer of 2007-2010 and autumn of 2007-2009 and estimated fecundity. A monitoring project examining the size-fecundity relationship began in 2012 and data is collected every other year.In June 2009 and 2010 we collected embryo clutches of recently extruded red king crab embryos in Bristol Bay, Alaska, to assess embryo quality based on dry weight, carbon and nitrogen content. To assess larval quality, we collected ovigerous females from Bristol Bay in 2007 and reared them in the laboratory until larval hatching in 2008. Larval quality based on dry weight, carbon and nitrogen content, and time to 50% mortality under starvation conditions was assessed.

Maternal effects on the quality of progeny can have direct impacts on population productivity. Rockfish are viviparous and the oil globule size of larvae at parturition has been shown to have direct effects on time until starvation and growth rate. We sampled embryos and preparturition larvae opportunistically from 89 gravid quillback rockfish (Sebastes maliger) in Southeast Alaska. Because the developmental stage and sampling period were correlated with oil globule size, they were treated as covariates in an analysis of maternal age, length, and weight effects on oil globule size. Maternal factors were related to developmental timing for almost all sampling periods, indicating that older, longer, and heavier females develop embryos earlier than younger, shorter, or lighter ones. Oil globule diameter and maternal length and weight were statistically linked, but the relationships may not be biologically significant. Weight-specific fecundity did not increase with maternal size or age, suggesting that reproductive output does not increase more quickly as fish age and grow. Age or size truncation of a rockfish population, in which timing of parturition is related to age and size, could result in a shorter parturition season. This shortening of the parturition season could make the population vulnerable to f luctuating environmental conditions.

This data set is from a series of laboratory experiments examining the interactions between red and blue king crabs and habitat. We examined how density and predator presence affect habitat choice by red and blue king crabs. Further experiments determined how temperature and habitat affect predation by year-1 red king crab on year-0 blue king crab. Finally, long-term interaction experiments examined how habitat and density affected growth, survival, and intra-guild interactions between red and blue king crab.

In giant crabs (Pseudocarcinus gigas), two sets of data were collected: the first examined changes in egg composition during embryogenesis and the second assessed effects of female size on egg composition.

Juvenile red and blue king crabs (Paralithodes camtschaticus and P. platypus) were exposed to three pH levels: ambient (pH 8.1), pH 7.8, and pH 7.5 for three weeks. Oxygen consumption and feeding ration were determined immediately after exposure to treatment water and after three weeks exposure. Growth can be calculated from the wet mass observations.

This is data from a laboratory experiment in which blue king crab juveniles were held at three different pHs (ambient, pH 7.8, and pH 7.5) for a year. Growth, survival, and morphology were recorded.

These data characterize treatments and outcomes in laboratory-based ocean acidification experiments conducted that the NOAA NEFSC Howard Laboratory. Experiments vary by species used, scope of study (experiment duration and species’ life-stages examined), and experimental design including number of treatments, levels, and replicates, and the suite of response variables. This experiment used summer flounder (Paralichthys dentatus) as subjects, one treatment (concentration of aqueous pCO2), three treatment levels (775, 1808, and 4714 uatm pCO2, pHs of 7.8, 7.5, and 7.1, respectively), three replicates (replicated downstream from each unique CO2 source), and the following response variables: survival of embryos to hatching and of larvae to age 28 d post-hatching; size, shape, and image-based developmental features of larvae; and histopathologically determined status of key organs (eye, heart, liver, gall bladder, gastro-intestinal tract, epidermis, kidney, spinal cord, and muscles) and cranio-facial and skeletal elements.

To study the effects of ocean acidification we examined the effects of ocean acidification on the larval stages of the economically important southern Tanner crab, Chionoecetes bairdi. Ovigerous females were reared in one of 3 treatments: control (ambient pH ~8.1), pH 7.8, and pH 7.5 for 2 years. Larvae in year 1 were from oocytes developed in the field whereas larvae in year 2 were from oocytes developed under acidified conditions. Larvae hatched each year, were also exposed to 3 pH treatments to examine starvation-survival, morphology, condition, and calcium/magnesium content. Approximately 300 larvae were stocked in multiple treatments for testing the effect of pH. Hatching success was measured as the total % of larval hatched from a full clutch while duration was the number of days over which hatching occurred. Hatching success did not differ among treatments in 2012 but varied between 46 to 87% in 2013 dependent on pH treatment. Larval mass was highest in pH 7.8 in 2012 and lowest in the control, however in 2013 the highest larval mass was in the control water. There were only small (not significant) changes in magnesium or calcium content among treatments in 2012 however, the reduction in both minerals at higher pH was greater in 2013. There was higher percent carbon and nitrogen contents in pH 7.5 larvae in 2013. The morphology of Tanner crab larval was assessed from 200 larvae stocked in multiple 2 L beakers. There was no effect of treatment on larval morphometrics. In 2012 and 2013, we examined if embryos developed under acidified conditions affected larval morphology by assessing 15 newly hatched larvae from each treatment. There was again no effect of treatment on larval morphometrics. Starvation survival experiments were performed in 1 L sized PVC inserts. In both years larvae from embryos that developed in pH 7.5 water survived about 3 days longer than those that developed in control water. However, in 2012 larvae from embryos that had developed in pH 7.8 water were similar to control larvae whereas in 2013 they were intermediate between the control and pH 7.5 larvae. The overall effects of treatment at the larval stage appeared to be better condition and initial survival at lower pH, however multiple years of treatment led to lower survival.