TITLE:    Palmer LTER: interannual comparison of lipid reserves for
          reproduction in the Antarctic krill, Euphausia Superba
AUTHORS:  D.K. Poehls, R.M. Ross, L.B. Quetin
DATE:     12-16 February 2001
PLACE:    The American Society of Limnology and Oceanography (ASLO),
	  Aquatic Sciences 2001, Albuquerque, New Mexico
THEME:    Making Connections in the 21st Century
URL:      http://www.aslo.org/albuquerque2001/

	    POSTER
	    PC05 - Zooplankton Production, Physiology, and Ecology

            University of California, Santa Barbara, Santa Barbara, USA


ABSTRACT
 Lipid content and the condition factor of the Antarctic
krill, Euphausia superba, a central species in the
Southern Ocean ecosystem, were analyzed for different sexual maturity
classes and interannual variation within maturity class. It has been
proposed that the reproductive cycle and capacity for females in any
one year are based on their fat (lipid) reserves accumulated during
spring months.  The C:N ratio and the condition factor (ug C per volume
of krill), both calculated from elemental carbon and nitrogen analysis,
should both increase as the individual puts on lipid reserves and/or
oocytes develop. If these condition factor indices yield the same
information as the lipid assays, a much simpler and inexpensive
technique for revealing interannual variation can be developed. 
Samples collected during 1996 and 1999, a highly reproductive year and
an average year respectively, on the annual summer cruises for the
Palmer LTER (Long Term Ecological Research west of the Antarctic
Peninsula) were compared.  Interannual differences were insignificant
but reproductive developmental stages show clear separation associated
with the development and release of preferentially lipid rich eggs.