TY - JOUR
T1 - Embryo biometry of three broadcast spawning euphausiid species applied to identify cross-shelf and seasonal spawning patterns along the Oregon coast
AU - Gómez-Gutiérrez, Jaime
AU - Peterson, William T.
AU - Miller, Charles B.
N1 - Funding Information:
This research was supported by funds provided by a Mamie Markham Research Award from Oregon State University, Hatfield Marine Science Center (HMSC) during 2001 – 2002 and 2003 – 2004. Samples from 1970 – 1972 were collected with Sea Grant support. The Office of Naval Research (National Ocean Partnership Program) in 1999–2000 and U.S. GLOBEC program in 2001–2002 (jointly funded by the National Science Foundation and National Oceanic and Atmospheric Administration) provided ship time and staff assistance. J.G.-G. was supported by an SNI II fellowship from EDI, COFAA-IPN and a CONACyT PhD grant (122676) to study at Oregon State University. Part of the data published here was supported by two CONACyT research grants 2004-01-144 and S007-2005-1-11717. This is publication 657 of the NEP GLOBEC Program. The manuscript was partially written during a sabbatical stay at the Australian Antarctic Division at Kingston, Tasmania co-funded by Instituto Politécnico Nacional and CONACyT (79528).
PY - 2010/6
Y1 - 2010/6
N2 - Morphology and biometry of eggs spawned by females of Euphausia pacifica, Thysanoessa spinifera and Thysanoessa inspinata were compared with eggs collected along the Oregon coast to identify the eggs in preserved samples to species level and to infer species spawning areas and intensity of spawning events in the field. The average chorion diameter (CD) and embryo diameter (ED) were significantly larger for E. pacifica than for T. spinifera. Euphausia pacifica eggs usually have a significantly greater perivitelline space, and the chorion is firm, transparent, smooth, elastic and completely spherical, while T. spinifera embryos are not completely spherical and typically are soft and sticky with particles attached. Eggs of the twitching stage embryo of T. spinifera have an elliptical shape, while those of E. pacifica are spherical to very slightly elliptical even after hatching as nauplii. The CD and ED of T. inspinata eggs were smaller than those of the other two species and they were transparent and spherical with a non-sticky chorion. Biweekly time series of eggs (identified to species), of nauplii + metanauplii and of ripe females collected along the Newport hydrographic line (44°40'N) during 1970-1972 show that E. pacifica and T. spinifera spawn mainly < 40 km from the coast from March to October, but E. pacifica also spawns regularly at oceanic locations. A meta-analysis of the egg CD and ED values of 38 euphausiid species around the world indicates that these variables alone cannot be used to identify eggs to species, excepting specific regions where one or two broadcast spawners dominate the euphausiid assemblage.
AB - Morphology and biometry of eggs spawned by females of Euphausia pacifica, Thysanoessa spinifera and Thysanoessa inspinata were compared with eggs collected along the Oregon coast to identify the eggs in preserved samples to species level and to infer species spawning areas and intensity of spawning events in the field. The average chorion diameter (CD) and embryo diameter (ED) were significantly larger for E. pacifica than for T. spinifera. Euphausia pacifica eggs usually have a significantly greater perivitelline space, and the chorion is firm, transparent, smooth, elastic and completely spherical, while T. spinifera embryos are not completely spherical and typically are soft and sticky with particles attached. Eggs of the twitching stage embryo of T. spinifera have an elliptical shape, while those of E. pacifica are spherical to very slightly elliptical even after hatching as nauplii. The CD and ED of T. inspinata eggs were smaller than those of the other two species and they were transparent and spherical with a non-sticky chorion. Biweekly time series of eggs (identified to species), of nauplii + metanauplii and of ripe females collected along the Newport hydrographic line (44°40'N) during 1970-1972 show that E. pacifica and T. spinifera spawn mainly < 40 km from the coast from March to October, but E. pacifica also spawns regularly at oceanic locations. A meta-analysis of the egg CD and ED values of 38 euphausiid species around the world indicates that these variables alone cannot be used to identify eggs to species, excepting specific regions where one or two broadcast spawners dominate the euphausiid assemblage.
KW - Biometry
KW - Chorion
KW - Eggs
KW - Embryos
KW - Euphausiid
KW - Krill
KW - Perivitelline space
UR - http://www.scopus.com/inward/record.url?scp=78650904282&partnerID=8YFLogxK
U2 - 10.1093/plankt/fbq028
DO - 10.1093/plankt/fbq028
M3 - Artículo
SN - 0142-7873
VL - 32
SP - 739
EP - 760
JO - Journal of Plankton Research
JF - Journal of Plankton Research
IS - 6
ER -