krill.length&weight 97jan 11 Jan to 13 Feb, 1999 [Palmer Station to Palmer Station dates] Wet weight, total length and sexual maturity of Antarctic krill from throughout the mesoscale Palmer LTER grid. total length (mm) wet weight (g) stage (j/sa, sa, imF, imM, mF, mM) j/sa = juvenile/subadult, used for individuals 18-28 mm in total length sa = subadult, individuals > 28 mm with no external secondary sex characteristics imF = immature female (thelycum) imM = immature male (petasma) mF = mature female mM = mature male event.number trawl.number or spawning frequency experiment.number (SPF#) Palmer.grid.location date (day-month-year) comments none The sampling frequency is based on the objective of freezing ~ 50 individuals in a range of sizes and sexual maturity stages from each cardinal transect line (600.*, 500.*, 400.*, 300.* and 200.*) during the cruise. The 50 individuals are taken from stations along the line. Healthy individual Antarctic krill are taken from both the 2-m and 1-m trawl catches, measured with digital calipers to 0.01 mm, then staged under the microscope. Total length (TL) is standard length 1, or the length from the tip of the rostrum to the tip of the uropods excluding spines (Mauchline, 1981). If the individual fills the size range and sexual maturity stage category desired, the krill is gently blotted dry, placed in a numbered pre-weighed vial, and frozen in a -80°C freezer. At the end of the cruise, the vial plus animal is weighed at Palmer Station. The same Mettler analytical balance is used for both the vial alone and the vial plus krill weights. The same 500 mg standard weight is used to check for drift in the balance at each weighing. For krill < 18 mm, the telson is inspected to distinguish between furcilia stages and the juvenile/subadult category. Krill in the size range between 18 and 28 mm are automatically categorized as juvenile/subadults, as they are too large for furcilia, and too small to have secondary sexual characteristics. Krill > 28 mm are inspected to see if a petasma (male, M) or thelycum (female, F) are present, and if the petasma and thelycum are immature (im) or mature (m). If neither can be found, the krill is categorized as a subadult. Three sizes of plastic vial are used: 1.5 ml vials for krill < 25 mm; 7 ml vials for 24-43 mm krill, and 20 ml vials for 43-60 mm krill. Ten vials of each size are frozen empty and reweighed at the same time as the vials containing krill. The difference in weight is averaged, and used to correct the wet weights of the krill. The objective is to generate a length versus weight relationship for a single transect with the krill coming from several LTER grid stations along the transect. A minimum of 10 males, 10 females, and 15 subadults and immatures are measured, sexed and frozen for each transect. The stations are divided into 4 groups: *.020 to *.080, *.060 to *.120, *.100 to *.160, and *.140 to *.200. The groupings correspond in general to inner, 2 middle and 1 outer shelf regions. From 11-15 individuals are frozen for each grouping of stations, with one from each 3 mm size range: 25-28, 28-31,.....56-59. For individuals < 25 mm, the size increment is 1.5 mm: 18.0-19.5, 19.5- 21.0 etc. For 97jan, 271 individuals were frozen: 73 in the 18-28 mm, and 198 in the 28-56 mm size ranges. Antarctic krill, wet weight and total length relationship The file is in ascii format, comma separated variables. In the first row the number before the ! indicates the number of variables. Rows 2 to 9 define the 8 variables. Data start in row 10. ~lter/~lterdata/97jan/trawl2m/* Velella on the MSILTER Apple network krill.length&weight Robin M. Ross, Langdon B. Quetin none Robin M. Ross and Langdon B. Quetin Marine Science Institute, UCSB, Santa Barbara, CA 93106 (805) 893-2096 robin@crseo.ucsb.edu or langdon@crseo.ucsb.edu RM Ross, CT Shaw, K Sauber On board sample analysis by above. RM Ross, CT Shaw RM Ross responsible for quality control of data sets. RM Ross 20 June 1999 Mauchline, J. 1981. Measurement of body length of Euphausia superba Dana. BIOMASS Handbook No. 4. SCAR/SCOR/IABO/ACMRR. Total length and wet weight were plotted against each other to detect outliers. Outliers were inspected for possible typographical errors, mislabelling etc, and the data base corrected. Of the 5 outliers in 273 entries, 3 were corrected and 2 discarded.