Dear MarMam Community, We are delighted to announce our most recent publication: Thometz NM, Dearolf JL, Dunkin RC, Noren DP, Holt MM, Sims OC, Cathey BC, Williams TM (2017) “Comparative physiology of vocal musculature in two odontocetes, the bottlenose dolphin (*Tursiops truncatus*) and the harbor porpoise (*Phocoena phocoena*)”. Journal of Comparative Physiology B. doi: 10.1007/s00360-017-1106-5. Abstract: The mechanism by which odontocetes produce sound is unique among mammals. To gain insight into the physiological properties that support sound production in toothed whales, we examined myoglobin content ([Mb]), non-bicarbonate buffering capacity (β), fiber-type profiles, and myosin heavy chain expression of vocal musculature in two odontocetes: the bottlenose dolphin (*Tursiops truncatus*; n=4) and the harbor porpoise (*Phocoena phocoena*; n=5). Both species use the same anatomical structures to produce sound, but differ markedly in their vocal repertoires. *Tursiops* produce both broadband clicks and tonal whistles, while *Phocoena* only produce higher-frequency clicks. Specific muscles examined in this study included: 1) the nasal musculature around the phonic lips on the right (RNM) and left (LNM) sides of the head, 2) the palatopharyngeal sphincter (PPS), which surrounds the larynx and aids in pressurizing cranial air spaces, and 3) the genioglossus complex (GGC), a group of muscles positioned ventrally within the head. Overall, vocal muscles had significantly lower [Mb] and β than locomotor muscles from the same species. The PPS was predominately composed of small diameter slow-twitch fibers. Fiber-type and myosin heavy chain analyses revealed that the GGC was comprised largely of fast-twitch fibers (*Tursiops*: 88.6%, *Phocoena*: 79.7%) and had the highest β of all vocal muscles. Notably, there was a significant difference in [Mb] between the RNM and LNM in *Tursiops*, but not *Phocoena*. Our results reveal shared physiological characteristics of individual vocal muscles across species that enhance our understanding of key functional roles, as well as species-specific differences which appear to reflect differences in vocal capacities. This manuscript was recently published online through the Journal of Comparative Physiology B, and the article can be accessed here: http://rdcu.be/s9fM <https://urldefense.proofpoint.com/v2/url?u=http-3A__em.rdcu.be_wf_click-3Fupn-3DKP7O1RED-2D2BlD0F9LDqGVeSK82udXrGPfApmmE484hzps-2D3D-5FzxbBPqnih7C6fiToETzZY1Rc25eyRISy-2D2FQrBkTtzNzg-2D2BjS2TjqJqy0j8YWNkWsuoJRIi4bPKqc1vO0GIe5t4PI8zDdeOGXdjdrRNy0jUO3pA46LjKKmNs7QhdZojfnT1245GPyATfJGHVKKihkm21jRoUILSBFXBeB6wVpbgRVX-2D2Feeux3xaM6E8WFLiRB4FbLcpTXNNIh0xbFtlBWcbZ7w-2D3D-2D3D&d=DwMFaQ&c=qgVugHHq3rzouXkEXdxBNQ&r=T7sgFgSHBMNn4NyOt1tPRwF2awquySgy1IA5lbapRWA&m=5Md4DPFfLN1nVsuEwuqOSE9KDHfxPEV51w9ry1oiwAo&s=wt9Y0PloUsKE7UnfBoauF3kwgiJinWfId5ThQ71JxYk&e=> Best, Nicole Thometz -- Nicole M. Thometz, Ph.D. Assistant Professor, Department of Biology University of San Francisco 2130 Fulton Street, San Francisco, CA 94117