trawlgen mar 93 28mar93-12may93 Trawl catch composition including total length and wet weight for individual Antarctic krill, Euphausia superba. Event #, tow #, transect #, station #, wet weight, total length, sex, mature or immature if male or female, notes on thelycum color and/or presence of spermatophores on occasion (1) total length: standard length 1 (mm), from the tip of the rostrum to the tip of the uropods, excluding spines (2) wet weight: wet weight (g) of individual krill Individuals measured and weighed from stations on 13 of the 14 transect lines sampled during this cruise plus from stations behind the Biscoe Islands continued these transect lines. No krill were measured from the 900.* line. For each transect line, individuals were taken in the full size range available from groupings of stations (*.020 to *.080, *.060 to *.120, *.100 to *.160, and *.140 to *.200), to total a minimum of 20 mature individuals (~ 10 males, ~ 10 females) and 15 to 20 immatures, subadults and juveniles if available. The objective was to collect the data to generate a length versus wet weight relationships for the entire cruise, and for selected regions such as inshore versus offshore or southern verus northern if desired. Krill were removed from the catch of both the 1-m and 2-m trawls for later chemical composition analysis. Individuals in the size range and sex category still needed for the transect line were selected. These individuals were measured with digital calipers, gently blotted dry on kimwipes or paper towels until no dampness appeared on the paper when the animal was turned, and placed in a preweighted plastic vial (20 or 7 or 1.5 ml). Development, whether mature or immature, of the thelycum (females) and petasma (males) was usually noted. Juveniles and subadults were separated by the disappearance of the second pair of postero-lateral spines on the telson on the molt to subadult. Subadults have no discernible secondary sex characteristics. All krill placed in a ziplock bag with others from the same70 transect line and frozen in a -70 C freezer shortly after measurement. Upon returning to the station at the end of the cruise, all vials were weighed within a few weeks. Vials were removed from the freezer in small groups (5 or 6) and placed in a bucket of crushed ice. Just before weighing on a Mettler AE 240 4-place balance, each vial was wiped with a kimwipe to remove accumulated frost. After the vial was weighed, it was returned to the freezer. During the brief weighing process the animals did not thaw. Sampling frequency and spatial distribution was designed to allow us to compare length_weight relationships both offshore and alongshore in the LTER Peninsula grid region. The relationship calculated between total length (mm) and wet weight (gm) for the entire mar93 data set (n = 370) was log(wet weight) = log (total length) * 3.231 - 5.478, r^2 = 0.974 total length and wet weight, euphausia superba ascii /home/data3/data/93mar/trwl_gen/ TL_WWT.csv Robin M. Ross, Langdon B. Quetin Robin M. Ross, Langdon B. Quetin Robin M. Ross, Tim Newberger, G. Catalano, T. Coe, H. Coe, S. Pryor, D. Post, L. Serold Robin M. Ross, Tim Newberger, G. Catalano, T. Coe, H. Coe, S. Pryor, D. Post, L. Serold H. Coe, T. Coe, G. Catalano, D. Post Robin M. Ross Robin M. Ross 17 November 1994 reformated csv file 23 November 1994 Fraser, F. C. 1936. On the development and distribution of the young stages of krill (Euphausia superba). Discovery Reports XIV: 1-192. Makarov, R. Larval development of the antarctic euphausiids. BIOMASS Handbook No. 3. SCAR/SCOR/IABO/ACMRR. Group of specialists on living resources of the southern oceans. Individuals responsible for measurements of total length cross calibrated their handling of krill and digital caliper by comparing the lengths measured on the same individual. Total length measurements of live animals are recorded to 0.01mm, and are accurate to 0.5 mm. The difference between accuracy and precision is primarily due to differences in the amount of "stretch" individual measurers give to the animals. At the beginning of each weighing session, a known standard weight (1 gram) is weighed on the balance to ensure that the weights are accurate. If the weight is within 0.0010 g, weighing proceeds. Changes in weight of the vials due to freezing have been investigated. Changes observed after 4 weeks in the freezer were of the same magnitude and direction as the weight of a 1 gram standard weight, and thus are due to machine error, not changes in vial weight over time. Total length was plotted against wet weight, and the plot inspected for outliers. Three data points were corrected after this inspection revealed data entry errors, and one outlier discarded of the 371 individuals frozen.

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