title: Gut reaction by heartless shrimps: experimental evidence for the role of the gut in generating circulation before cardiac ontogeny.
abstract: Before the appearance of a functional heart in many invertebrate species, the assumption was that general body movements provide circulatory function. Consequently, I investigated the frequency of gut movements in the brine shrimp, Artemia franciscana, immediately post-hatch to the point when a functional heart appeared. Prior to cardiac ontogeny, movements of internal musculature and gut provided pre-cardiac circulatory currents with the rate of gut movements increasing when swimming limbs were impeded. There was also some evidence that gut movements were responsive to low oxygen, indicating a possible regulatory function for the gut in early circulation. Overall, this suggests that general body movements are not always adequate to provide internal circulation in small, heartless individuals.
authors.affiliation: Marine Biology and Ecology Research Centre, School of Biological Sciences, University of Plymouth, Plymouth PL4 8AA, UK. jispicer@plymouth.ac.uk
authors.forename: John I
authors.initials: JI
authors.lastname: Spicer
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001156:Artemia / Q000254:growth & development / Q000502:physiology*; D001775:Blood Circulation / Q000502:physiology; D005769:Gastrointestinal Motility; D006321:Heart / Q000254:growth & development; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D007422:Intestines / Q000187:drug effects / Q000502:physiology; D010100:Oxygen / Q000494:pharmacology
chemical_list: D010100:Oxygen