Early development of Calanus glacialis and C. finmarchicus

Abstract

Egg and nauplii development of coexisting populations of Calanus glacialis and C. finmarchicus from Disko Bay, western Greenland, were measured in the laboratory with, and without addition of food. Egg hatching rate was measured at five temperatures from 0 C to 10 C and the fit to a Bel ehr adek equation was highly significant (r 2 > 0.99). There was little difference between hatching and development rates of the two species; however, the egg hatching rate at low temperatures was faster than predicted from measurements made in other areas. Also, nauplii development times at 0 C were similar, with C. glacialis and C. finmarchicus reaching nauplii stage N6 after 44 d and 48 d, respectively. The laboratory-reared nauplii could be separated accurately to species by stage and length alone. However, separation by size was not possible for the in situ community of nauplii where the influence of food, temperature, and size-dependent predation mortality, made the size distribution more variable and overlapping.The Arctic environment is warming with reduced sea ice cover and accelerated melting of inland glaciers. These changes in forcing factors alter the physical settings for the biological processes and succession in the ocean (IPCC 2013). Therefore, a major effort has been made to investigate and predict how temperature changes impact the vulnerable Arctic marine ecosystems.

Early ice retreat and ocean warming may induce copepod biogeographic boundary shifts in the Arctic Ocean

“…This assumption implies that modeled individuals that reproduced as eggs prior to the bloom onset would halt at the beginning of N3 until food emerges in the water column. The laboratory experiment supported that development of starved C. glacialis eggs/nauplii could arrest at stage N3 for more than 1 month without significant mortality [ Jung‐Madsen and Nielsen , ].…”

“…Both temperature and food availability determine development time and rate in copepods, with life stage development being significantly prolonged under food limitation [ Campbell et al ., ; Cook et al ., ; Daase et al ., ; Jung‐Madsen and Nielsen , ]. Here age was updated using temperature‐ and food‐dependent development rate derived from Belehrádek [] and Ivlev [] functions with coefficients fitted to the laboratory data.…”

“…Here age was updated using temperature‐ and food‐dependent development rate derived from Belehrádek [] and Ivlev [] functions with coefficients fitted to the laboratory data. Under food saturation, the development time D i (days) at the i th stage (or stage duration) can be expressed as where a i and α are fitting parameters, T is temperature (in °C), and β is a constant for a range of copepod species [ Corkett et al ., ; Campbell et al ., ; Jung‐Madsen and Nielsen , ]. The derivations of the above parameters can be found in Ji et al .…”

“…However, the role of food availability in development could not be well addressed in that study because of the limited spatiotemporal resolution of satellite‐based chlorophyll (food) estimation that was used to provide food to the IBM and the inability of satellites to estimate chlorophyll in ice‐covered areas and in subsurface layers. Food limitation has been found to significantly prolong copepod development time in many laboratory calanoid copepod experiments [e.g., Campbell et al ., ; Cook et al ., ; Daase et al ., ; Jung‐Madsen and Nielsen , ]. Parameterizing food limitation in addition to temperature‐dependent copepod life history development is a critical improvement over the work of Ji et al .…”

Effect of temperature on egg development time and productivity of Acartia steueri and population variations of family Acartiidae in Dadaepo Beach, Busan, Korea

“…Hatching rates of A. tonsa was highest at 23ºC (92.2%), but there was no hatching 12ºC (Holste and Peck, 2006). The hatching success of Calanus glacialis and C. finmarchicus from Disko Bay, Western Greenland was highest at low temperature (0ºC) and the egg development time of two species decreased with increasing temperature between 0ºC and 10ºC (Jung-Madsen and Nielsen, 2015). Because the optimum temperature of two species in Arctic was lower than experiment temperature regimes.…”