{"id":614,"date":"2019-06-27T15:20:17","date_gmt":"2019-06-27T19:20:17","guid":{"rendered":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/?page_id=614"},"modified":"2026-06-30T09:55:54","modified_gmt":"2026-06-30T13:55:54","slug":"copepod-physiology","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/research\/copepod-physiology\/","title":{"rendered":"Copepod Physiology"},"content":{"rendered":"\n\n\t

Copepod Physiology<\/h1>\n\t\t\t\t\n\t\t\t\t\"Calanus\"\n\t\t\t\t<\/a>\n\t

Calanoid copepods are among Earth’s most abundant animals, and they play a key role in moving energy from the base of the food chain to higher consumers. Some copepods, such as\u00a0Calanus finmarchicus<\/em>, can undergo a dormant period (diapause) during their juvenile development. It is not well understood how copepods “decide” whether to undergo diapause, or when to enter or exit diapause. Work in our lab focuses on understanding how the physiological condition of lipid-storing copepods changes in relation to their environment, how diapause helps copepods to adapt to their environment, and how copepod populations may respond to future environmental change.<\/p>\n

Some areas of interest:<\/h2>\n

Effects of nutrient limitation on microalgal nutitional quality for copepods<\/h3>\n

Nutrient limitation structures the taxonomic composition, abundance, and physiology of producers, and consequently the prey abundance and quality available to consumers. While some types of marine microalgae are strictly autotrophic, others are able to ingest particles in a form of mixotrophy. It has been proposed that mixotrophs<\/strong> have more stable nutrient stoichiometry under variable\/limiting nutrient conditions, which could make them a particularly valuable nutritional resource. We have been studying the effects of nutrient limitation on food quality of microalgae through lab experiments and field sampling. We have been particularly interested the extent to which mixotrophs may be able to better maintain their food quality as nutrients become scarce.<\/p>\n

Our lab experiments have focused on the copepod\u00a0Centropages typicus<\/em>, which is abundant in shelf environments in the northwest Atlantic including the Gulf of Maine. Notably it has limited lipid stores, which make it well-suited to short-term feeding experiments. We reared a suite of microalgal taxa under nutrient replete and nutrient limited conditions, including Dunaliella sp.,<\/u><\/em> Pyramimonas parkeae, Heterocapsa triquetra, Rhodomonas salina <\/em>and Thalassiosira weissflogii.<\/em> We have measured nutrient stoichiometry and fatty acid composition in these algae. We have also conducted short-term feeding experiments with\u00a0C. typicus <\/em>and measured a variety of biological responses including grazing rate, mortality, egg production and naupliar hatching rates.<\/p>\n

\"\"<\/p>\n

We are still analyzing our results (and conducting a few “follow-up” experiments…it’s hard to resist!). We presented some preliminary results at the 2026 ASLO-SIL meeting. A key takeaway so far, is that under nutrient replete conditions diatoms can support high levels of egg production, but food quality appears to decline under nutrient limitation. In contrast, some of the non-diatom taxa supported more consistent (but sometimes lower) levels of egg production under both nutrient replete and nutrient limited conditions.<\/p>\n

This project is co-led by Rebecca Gast is funded by the Biological Oceanography Program at NSF.<\/p>\n

Metabolic adaptations of Antarctic Copepods<\/h3>\n

Antarctic copepods have developed particular feeding and behavioral strategies to survive in their very seasonal environment, it is not known how each of these species will respond to environmental change. We conducted field sampling and ship-based experiments with female copepods to examine and compare these adaptations across species and to understand they respond to short-term changes in food availability. Field work for this project was conducted through a collaboration with the Palmer Long-Term Ecological Research<\/a> Program. I wrote many blog posts about the field work and a few about the subsequent analysis (all “rolled up” here: Antarctic_blog<\/a>).<\/p>\n

Both Calanus propinquus\u00a0<\/em>and\u00a0Calanoides acutus\u00a0<\/em>are large-lipid storing copepods that comprise significant portions of the antarctic mesozooplankton. Calanoides acutus\u00a0<\/em>is primarily herbivorous, stores large amounts of wax ester lipids, and overwinters at depth in diapause. In contrast\u00a0Calanus propinquus\u00a0<\/em>is omnivorous with a more diverse diet, primarily stores triglycerides, and stays relatively active during the winter. We found that\u00a0C. acutus\u00a0<\/em>(the “herbivorous diapauser”) showed stronger transcriptional responses to experimentally-induced starvation, and showed similar changes in gene expression in the field in areas with low chlorophyll abundance. In contrast,\u00a0C. propinquus <\/em>showed weaker responses to starvation and less metabolic variation in the field. From this it appears that\u00a0C. acutus\u00a0<\/em>is more sensitive to short-term starvation ,which is consistent with a strong reliance of C.\u2009acutus<\/i> on continuous feeding on phytoplankton to support egg production.. We also learned that the clade of lipid-storing copepods (which includes both C. acutus\u00a0<\/em>and\u00a0C. propinquus<\/em>) has experienced diversification and positive selection of key enzymes involved in lipid synthesis. In addition, Selection on starvation-responsive genes has been particularly strong within this lineage, underscoring the significance of starvation tolerance as a key adaptation for these species.<\/p>\n

This project was funded by the Office of Polar Programs at NSF.<\/p>\n

 <\/p>\n

List of our copepod-related publications.<\/a><\/p>\n\n","protected":false},"excerpt":{"rendered":"

Copepod Physiology Calanoid copepods are among Earth’s most abundant animals, and they play a key role in moving energy from the base of the food chain to higher consumers. Some copepods, such as\u00a0Calanus finmarchicus, can undergo a dormant period (diapause) during their juvenile development. It is not well understood how copepods “decide” whether to undergo…<\/p>\n","protected":false},"author":83,"featured_media":0,"parent":606,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/pages\/614"}],"collection":[{"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/users\/83"}],"replies":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/comments?post=614"}],"version-history":[{"count":3,"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/pages\/614\/revisions"}],"predecessor-version":[{"id":1295,"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/pages\/614\/revisions\/1295"}],"up":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/pages\/606"}],"wp:attachment":[{"href":"https:\/\/www2.whoi.edu\/site\/tarrantlab\/wp-json\/wp\/v2\/media?parent=614"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}