SPF 00jan 9 Jan to 25 Jan, 2000 [Palmer Station to Palmer Station dates] Spawning frequency and egg production experiments were conducted on board the Laurence M. Gould (00-01) in a flow-through aquarium at ambient temperature according to the method of Ross and Quetin (1983). These experiments yield estimates of spawning intensity, i.e. the percent of the females in the reproductive cycle spawning per day, and the interbrood period or interval between multiple batches of eggs. Measurements of egg size and the batch volume are indices of individual reproductive output during the cruise. Female total length, period spawned, egg batch volume, egg diameter. Details of experiments include: experiment number, initial temperature, and for each 12-h observation period - time checked, temperature of the seawater in the individual spawning jars, and number of females spawned. The summary includes experiment number, event number, trawl number, day/month start, local time start, grid location, average temperature, total number of spawners, total number of females in the experiment, duration of experiment, and calculated spawning frequency. Spawning frequency (% spawning per day) is: 100 * (no. spawners/no. females in experiment)/days of experiment The inverse of the spawning frequency is the interbrood period. Experiments are conducted as indicated by female status, i.e. adequate number of females with red thelycums, with the objective of one experiment per transect line. Due to the shortness of the cruise, only four experiments were conducted during the 00Jan LTER cruise: two each in the northern half (at 600.100 and 500.120) and southern half (at 200.100 and 200.a60) of the grid. Euphausia superba are collected with the 2-M trawl for these experiments, either with standard tows or with targeted tows. Experiments are conducted on board in the aquarium room in flowing seawater tables. All live individuals with red thelycums from a catch are gently transferred from the initial catch tub to a second tub filled with cold seawater. The red thelycum indicates that the female is in the reproductive cycle. Fifty females are randomly selected from the total by picking a spot in the tub and only removing those individuals that swam through the spot. Each female selected is placed in a 2-liter glass jar filled with filtered seawater and with a 3000 µm mesh circle partway down the jar to prevent the female from damaging the eggs after release. Each jar is checked for the presence of eggs every 12 h for 4 days. If eggs are seen, the female is given an additional 6 h to completely release the batch. The female is then removed, the total length measured, and then preserved individually in 5% buffered formalin. Total length is measured with digital calipers from the tip of the rostrum to the end of the uropods. The eggs are collected by attaching a funnel apparatus terminated with a scintillation vial to the 2-liter jar, inverting the jar, and allowing the eggs to sink into the scintillation vial over the next 1-2 h. The entire batch of eggs is then preserved in 5% buffered formalin. With this timing, eggs are preserved by a maximum age of 18-20 h and before the diameter of the egg begins to increase (Quetin and Ross, 1984). At the end of the experiment all non-spawners are measured fresh and either frozen individually or preserved as a group of non- spawners. In the laboratory at UCSB or at Palmer Station, diameters, including the perivitelline membrane, of 30 eggs from each batch are measured under a dissecting microscope. The total volume of the batch of eggs is measured to the nearest 0.025 in a narrow (0.4 mm ID) tube calibrated with a volumetric pipette and marked in 0.05 ml increments. Spawning frequency experiments are planned for the outer edge of each transect line (grid stations 160, 180 or 200) in order to observe any alongshore gradients in spawning intensity or reproductive output. spawning intensity, spawning frequency, interbrood period, fecundity, reproductive output In the first row a "!" is preceded by the number of columns of data (n) and followed by information about the experiment. Each column is described in the subsequent n rows. Data follows as comma separated text. ICESS, University of California at Santa Barbara http://www.icess.ucsb.edu/lter/ study - ~98janb/SPF Raw data from each experiment is in files named SPF(experiment number).dat. The header for each file contains the study, spawning frequency experiment number, and event number. Columns of data are: female total length (mm), spawning period, egg batch volume, female id number, and notes. SPF.sum is a summary file for all experiments during the cruise. Data include experiment number, event, tow, date of start of experiment, local time start, LTER grid location, average temperature, number of spawners, number of females in experiment, duration of experiment, and spawning frequency over the experiment. SPF.details is a file with details of local time experiment checked, temperature, and number of spawners for each of the observation periods (usually 8) for each experiment. Robin M. Ross and Langdon B. Quetin Marine Science Institute University of California at Santa Barbara Santa Barbara, CA 93106 Robin M. Ross and Langdon B. Quetin Marine Science Institute University of California at Santa Barbara Santa Barbara, CA 93106 Robin@icess.ucsb.edu, langdon@icess.ucsb.edu Experiments conducted and females measured by LB Quetin, JL Jones, CT Shaw, D Conlin, K Grimm and J Kneebone on board the L. M. Gould. J Kneebone measured the diameters of egg, the batch volumes for each female, and did incremental counts and volumes for several batches of eggs to set up the relationship between egg diameter and number of eggs per volume. RM Ross, J. Kneebone and CT Shaw RM Ross and CT Shaw RM Ross 6 June 2000 Ross, RM and LB Quetin. 1983. Spawning frequency and fecundity of the Antarctic krill Euphausia superba. Marine Biology 77, 201-205. Quetin, LB and RM Ross. 1984. Depth distribution of developing Euphausia superba embryos, predicted from sinking rates. Marine Biology 79, 47-53. At start of data collection PIs train and supervise new members of the research team to ensure that measurements are consistent across experiments and cruises. Data entry checked by a second person, both by proofing and by inspecting graphs for outliers.

Datafile Form V1.2 for describing a data file.