trawlgen nov91 07nov91-21nov91 Trawl catch composition including total length and wet weight for individual Antarctic krill, Euphausia superba. krill.tl.wwt: Event # tow # total length: standard length 1 (mm), from the tip of the rostrum to the tip of the uropods, excluding spines wet weight: wet weight (g) of individual krill trawl.catch: Individuals measured and weighed from all 3 transect lines sampled during this cruise, and from all stations on the 500.* and 600.* lines and from 2 of the 8 stations on the 700.* line. About 20 to 30 individuals were frozen from each of these stations: ~ 10 males, ~ 10 females, and 10 to 15 immatures (subadults, juveniles, late furcilia). Krill were removed from the catch of both the 1-m and 2-m trawls for later chemical composition analysis. From 20 to 30 individuals in a wide size range 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. Sex categories were male, female, juvenile and subadults combined, furcilia 6, adults with no thelycums identified as M*. Level of maturity of secondary sex characteristics was not routinely characterized. Females with red thelycums were noted for some stations, and these females had mature thelycums. Large krill were placed in a 20 ml plastic vial, small krill in a microcentrifuge tube. All krill from one station were placed in a ziplock bag 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 and wet weight for the entire Nov 91 data set (n=277) was log(wet weight(gm)) = log(total length(mm)) * 3.078 - 5.215, r2=.995 total length and wet weight, euphausia superba, krill ascii /home/data3/data/91nov/trwl_gen/ TL_WWT.csv Robin M. Ross, Langdon B. Quetin none Robin M. Ross, Langdon B. Quetin Langdon B. Quetin, Tim Newberger, M. Talkovic, V. Vredenberg, Cathy Lascara Langdon B. Quetin, Tim Newberger, M. Talkovic, V. Vredenberg, Cathy Lascara Langdon B. Quetin, Tim Newberger, M. Talkovic, V. Vredenberg, Cathy Lascara Robin M. Ross Robin M. Ross November 4, 1994 Nov 22, 1994 - format changed for ease of use 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. No measurements were dropped after this inspection.

Datafile Form V1.2 for describing a data file.