Modelling the dynamics of growth, development and lipid storage in the marine copepod Calanus finmarchicus

Abstract

Mechanistic models are essential tools for interpreting and predicting the consequences of a changing environment and stressors such as pollution on the life histories of marine organisms. Here, we apply the simple and generic energy-budget model DEBkiss to the life history of the marine copepod Calanus finmarchicus. Model modifications were needed to accommodate the copepod life cycle, which deviates in several respects from most other animals (e.g., a sudden stop of growth after the final moult). We identified an acceleration of growth in the early copepodite stages, which could be linked to an increase in the specific feeding rate of the animals. Lipid storage, an essential element of C. finmarchicus biology, was successfully captured with the reproduction buffer of the DEBkiss model. The resulting model was fitted to a detailed data set from the literature and was able to explain growth, development and lipid storage from egg to adult, at different temperatures and food availabilities, within a single consistent framework. The parameterised model could subsequently be used to elucidate the energetic constraints on gonad maturation and reproduction. Interestingly, the overhead costs for egg production seem to be substantially higher than the default value applied in DEB-based studies. The current model provides a solid basis for applications in stress ecology, although our model analysis also identified several knowledge gaps. Specifically, further research is needed to cover the dynamics of diapause and gonad maturation, to explain the dependence of maximum body size on food and temperature, and to verify the predicted high costs for maturity maintenance.Electronic supplementary materialThe online version of this article (doi:10.1007/s00227-016-3030-8) contains supplementary material, which is available to authorised users.

Stable isotopic evidence of nitrogen sources and C4 metabolism driving the world’s largest macroalgal green tides in the Yellow Sea

“… δ 13 C (‰) Location Source C3 producers −28.1 ± 2 — 84 C4 producers −13 ± 1.5 — “ C3 producers −22 to −35 — 76 C4 producers −11 to −17 — “ Green algae: U. prolifera −21.9 to −14.9 Yellow Sea This study Ulva sp. −14.2 to −10.1 New South Wales coast 85 Ulva lactuca −13 to −11 SE Brazil coast 86 “ −22.5 to −22.3 Mediterranean Sea 87 Ulva intestinalis −12.5 Neva estuary 88 Cladophora glomerata −15.5 to −12.5 “ “ Cladophora sp. −20 to −18 Gulf of Mexico 89 Codium sp.…”

“… −19.5 to −16 “ 91 Sargassum sp. −16.3 to −10 New South Wales coast 85 Sargassum vulgare −13 to −12 SE Brazil coast 86 Sargassum sp. −15 to −12.5 Baltic Sea 88 Cystoseira amentacea −19.7 to −15.8 Mediterranean Sea 87 Red algae: Pterocladium capillacea −16.7 to −13.5 New South Wales coast 85 Gelidiella acerosa −19 SE Brazil coast 86 Pterocladiella capillacea −33 to −32 “ “ Cryptonemia seminervis −30 “ “ Gracilaria sp.…”

Limited impact of an invasive oyster on intertidal assemblage structure and biodiversity: the importance of environmental context and functional equivalency with native species

“…The potential of C. gigas to alter species assemblages has been already widely known (Kochmann et al 2008 ; Markert et al 2009 ; Padilla 2010 ; Green and Crowe 2014 ; Norling et al 2015 ). Comparisons with other native habitat engineers, such as the blue mussel M. edulis , have shown that these changes are dependent on the structural properties of the ecosystem engineer (Buschbaum et al 2006 ; Gain et al 2017 ). Similarities in epifaunal assemblages associated with both C. gigas and O. edulis support these findings and emphasise the importance of the unique biogenic habitat provided by oysters.…”

“…Other species interaction may play a major role in determining such species abundance patterns. For example, is it likely that mechanisms interfering with successful recruitments, such as propagule pressure and abundance of grazers disturbing recently settled barnacle larvae or algae seedlings, may vary with time and location, while biological interactions may change with the maturity of oyster reefs (Jenkins et al 2000 ; Holmes et al 2005 ; Rezek et al 2017 ). High densities of C. gigas may also limit the initial abundance of early colonizers such as barnacles possibly by ingestion of larval stages (Troost et al 2008 ), but may prove to be a refuge from predation through the provision of complex three-dimensional structure for matured communities, thereby causing an accumulation of individuals over time (Grabowski 2004 ).…”

“…So far, juvenile oyster clusters of both species have been found to support similar species assemblages and diversity on hard substratum (Zwerschke et al 2016 ). Yet, it is unclear whether species assemblages and diversity would differ between C. gigas and O. edulis in different habitat types or in mature oyster beds owing to more pronounced differences in morphology and life history traits of each oyster species (Mann 1979 ; Green 2017 ; Nielsen et al 2017 ).…”