krillgrowth 91nov 13nov91-18nov91 Instantaneous growth rate and molting frequency of Antarctic krill from experiments held on board ship at ambient temperatures for short periods. Animal: sex, total length, molt period, telson length of animal and molt if molted Experimental: temperature of seawater, time observed animals for presence ofmolts, dead animals 1) molting frequency (%/day): 100 * number molters/number of experimental animals/duration of experiment in days. the inverse of the molting fequency is the intermolt period in days 2) percent growth per intermolt period (% growth/IMP): 100 * (animal telson - molt telson)/molt telson Five adultIGR and one larvalIGR experiments were conducted in 91nov. Only krill in good physiological condition were used in IGR experiments, i.e. swimming, no white sections in abdomen. Krill were used from either standard tows or targeted tows. All lively swimming krill were gently placed in a large volume of cold seawater, and then 100 randomly selected krill were gently placed in individual 2-liter vessels in a flowing seawater table at ambient temperature. Temperature was recorded, and animals were checked every 12 hours for molts over the following 4 days. Dead or unhealthy animals were noted. Once an animal molted, both animal and molt were removed from the vessel. The molt and animal were preserved together in 10% formalin. At the end of the experiment, the non-molters preserved together. The total length and lengths of the telson of all animal and their molts and the total lengths of the non-molters were measured under a binocular microscope back at University of California at Santa Barbara. Total length is from the tip of the rostrum to the end of the uropods, not including spines (Standard Length 1, Mauchline 1981). Dead or dying animals were excluded from experimental totals, but their total lengths recorded. Instantaneous growth rate (IGR) experiments were conducted across the grid to observe growth both on and off shore, four on the 500 line, one on the 700 line. Ice cover in the region prevented us from sampling krill and conducting experiments in the southern region of the Palmer LTER. IGR experiments in the 9191pal season and on the 91nov cruise were numbered sequentially without regard to whether the experiments was done on larval or adult krill or on station or at sea; the 91nov experiments are number 2-6. Of these five experiments, two were primarily juveniles or AC0 and designated larvalIGRs, three were adultIGRs. antarctic krill, growth rates, molting frequency ascii, comma separated variable There are 2 summary files for each study plus individual files for each experiment. 1) IGR.details gives the details of the experimental checking, with experiment number, initial temperature, local time of checking for periods 1-8, temperature of seawater at time of checking periods 1- 8, and number of molters at time of checking periods 1-8. 2) IGR.sum is a summary of results, with experiment number, event number, trawl number, day/month started, local time started, grid location, average temperature (¡C), number of molters, number of animals in experiment, duration of experiment, molting frequency (% per day). 3) in directories called AIGR and LIGR are located files containing the length measurements and sexual identification for each experiment: sex (im immature; F female; M male; J/SA juvenile or subadult; MM mature male; MF mature female) or stage of the individual (furcilia 1-6), animal total length (mm), molt period, animal telson length (mm), molt telson length (mm), comments (dead animals; problems; etc) ~lter/lterdata krill mac and robin's mac /91nov/* IGR.details IGR.sum /adultIGR AIGR(experiment number)ev(event number).dat [2-35; 3-110; 5-149] /larvalIGR [4-140; 6-149] Robin M. Ross, Langdon B. Quetin none Robin M. Ross, Langdon B. Quetin Langdon B. Quetin, Tim Newberger, Cathy Lascara, T. Moylan, M. Talkovic, V. Vredenberg C. Wyatt-Evens C. Wyatt-Evens, C.T. Shaw, Robin M. Ross Langdon B. Quetin, Robin M. Ross Langdon B. Quetin Individual files on experiments submitted 10 Jan 1996. IGR.details submitted 22 Dec 1996 IGR.sum submitted 22 Dec 1996 IGR experiments with this protocol conducted with Antarctic krill wer reported in: Quetin, L. B. and R. M. Ross. 1991. Behavioral and physiological characteristics of the Antarctic krill, Euphausia superba. Amer. Zool. 31: 49-63. Ross, R. M. and L. B. Quetin. 1991. Ecological physiology of larval euphausiids, Euphausia superba (Euphausiacea. Memoirs of the Queensland Museum 31: 321-333. C. Wyatt-Evens measured all telson lengths in a laboratory setting where accurate measurements under a microscope are easier after comparison of the results from on board measurement showed that although the average % growth per intermolt period was the same when multiple individuals measured the animals and molts, the variance was decreased when just one person measured all the animals.

Datafile Form V1.2 for describing a data file.