Abstract

Under managed care, sea stars may need to be removed from the water of touch tanks or for research protocols, husbandry, or veterinary procedures. The objective of this study was to use a point-of-care blood gas analyzer (iSTAT®, Abbott Diagnostics, Lake Forest, IL, USA) to evaluate changes in coelomic fluid respiratory gases and acid-base status of adult, subtidal, common sea stars (Asterias rubens) after four minutes of emersion at ambient temperature. Paired coelomic fluid samples (n=20) were analyzed with one sample collected immediately tankside (within 10 s of removal from the water) and the second sample collected after four minutes of emersion. Coelomic fluid was drawn using a needle and syringe from the aboral surface of the distal tip of the ray and analyzed immediately (within 10 s) using a point-of-care blood gas analyzer and calculated temperature corrections¹ of pH, pCO₂, and pO₂. After four minutes of emersion, coelomic fluid of sea stars had significantly lower pH (TC) (p<0.001), pO₂ (TC) (p<0.001), BE (p=0.001), HCO₃ (p=0.007), and sO₂ (p<0.001) compared to their tankside samples. Although statistically insignificant, pCO₂ (TC) was trending upwards in emersion samples. The effects on oxygenation status and coelomic fluid acid-base balance following short-term emersion likely have negative physiological impacts; thus, every effort should be made to keep subtidal sea stars submerged in water at all times and to collect samples immediately after emersion for obtaining diagnostic results that accurately represent coelomic fluid analytes of sea stars in their habitat.

Acknowledgements

This project was funded by an American Association of Zoo Veterinarians Wild Animal Health Fund grant. The authors wish to thank Don Behringer, Nancy Denslow, Salvatore Frasca Jr., Alisa Newton, Andrew Kane, Ross Brooks, Kevin Kroll, Celine Dalrymple, Haley Diefenbaugh, Kristina Edmiston, Jamie Garde, Miranda Gibson, Makenzie Griffin, and Miranda Jackson.

*Presenting author
+Student presenter

Literature Cited

1.  Innis CJ, Tlusty M, Merigo C, Weber ES. Metabolic and respiratory status of cold-stunned Kemp’s ridley sea turtles (Lepidochelys kempii). J Comp Physiol B Biochem Syst Environ Physiol. 2007;177(6):623–630.