“…Extensive biomedical studies on humans and related species have greatly improved our understanding of how this system works (Brodin & Davis, ; Demas & Nelson, ) and helped guide the development of diagnostic assays and biomarkers used to measure immune responses to pathogens and diseases. Conversely, immune function in nonmammalian vertebrates has not been well studied (Bowden et al, ; Uller, Isaksson, & Olsson, ; Zimmerman, Paitz, Vogel, & Bowden, ), and their immune responses are likely influenced by many factors including metabolic capacity (Chen, Cuijuan, & Pu, ; Hsu, ), endocrine fluctuations (Martin, Weil, & Nelson, ), season (Bowden et al, ; Munoz & De la Fuente, ; Sandmeier, Horn, & Tracy, ), temperature (Goessling et al, ; Zapata, Varas, & Torroba, ), and other environmental conditions (Martin et al, ; Origgi, ).…”