Journal of Comparative Physiology B

{{Infobox journal

| title = Journal of Comparative Physiology B

| image = Journal_of_Comparative_Physiology_B_cover.jpg

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| former_name =

| abbreviation = J. Comp. Physiol. B

| bluebook =

| discipline = Comparative physiology

| peer-reviewed =

| language =

| editor = Gerhard Heldmaier

| publisher = Springer Science+Business Media

| country =

| history = 1984–present

| frequency = Monthly

| openaccess =

| license =

| impact = 2.517

| impact-year = 2017

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| ISSN = 0174-1578

| eISSN = 1432-136X

| CODEN = JPBPDL

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| LCCN = 90656005

| OCLC =

| website = https://link.springer.com/journal/360

| link1 = https://link.springer.com/journal/volumesAndIssues/360

| link1-name = Online access

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The Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology is a monthly peer-reviewed scientific journal of comparative physiology. It was established in 1984, when it was split off from the Journal of Comparative Physiology. The editor-in-chief is Gerhard Heldmaier (Universität Marburg). The journal become electronic only in 2017.