A new species of baleen whale (Balaenoptera) from the Gulf of Mexico, with a review of its geographic distribution

Abstract

Bryde's-like whales are a complex of medium-sized baleen whales that occur in tropical waters of all three major ocean basins. Currently, a single species of Bryde's whale, Balaenoptera edeni Anderson, 1879, is recognized, with two subspecies, Eden's whale, B. edeni edeni and Bryde's whale, B. edeni brydei (Olsen, 1913), although some authors have recognized these as separate species. Recently, a new, evolutionarily divergent lineage of Bryde's-like whale was identified based on genetic data and was found to be restricted primarily to the northern Gulf of Mexico (GOMx). Here, we provide the first morphological examination of a complete skull from these whales and identify diagnostic characters that distinguish it from the other medium-sized baleen whale taxa. In addition, we have increased the number of genetic samples of these Bryde's-like whales in the GOMx from 23 to 36 individuals, all of which matched the GOMx lineage.A review of Bryde's-like whale records in the Caribbean and greater Atlantic supports an isolated distribution for this unique lineage, augmenting the genetic and morphological body of evidence supporting the existence of an undescribed species of Balaenoptera from the Gulf of Mexico.

Sounding the Call for a Global Library of Underwater Biological Sounds

“…As a result, reported distributions of these species are being expanded. Even some of the great whales are being found in places they were not expected (Allen et al, 2021), and occasionally a new species (Rosel et al, 2021) or a new sound (Rice et al, 2014;Cerchio et al, 2020) is discovered. This fact could prove vital for soniferous fauna, as our ever-changing climate ensures that many species are modifying their distributions and broadening or reducing their ranges (e.g., Scheinin et al, 2011;Ramirez et al, 2017;Bonebrake et al, 2018).…”

Response to Corkeron et al. “Balaenoptera ricei is also the Gulf of Mexico whale”

“…It has been more than a year since the species description was published and the common English name Rice's whale proposed (Rosel et al, 2021). There have since been extended efforts to get the message out about Rice's whales including updating federal websites (e.g., messaging on National Marine Fisheries Service 1 and National Data Buoy Center websites), updating the large whale sighting hotline for reporting Rice's whale sightings, and providing web stories.…”

Balaenoptera ricei is also the Gulf of Mexico whale

“…Gulf of Mexico are a separate species of Balaenoptera. As this new species is believed to number only a few tens of individuals (Rosel et al, 2021), this is a significant finding for cetacean conservation. Naming the whale Balaenoptera ricei, honoring Dale W. Rice for his substantial contributions to cetacean biology, is appropriate, and welcomed.…”

“…All the other baleen whale species or subspecies are named after geographic areas either in their specific binomial (B. borealis), subspecific trinomial (B. physalus patachonica), common name, or both (e.g., B. musculus indica, the Northern Indian Ocean blue whale). Balaenoptera ricei is thus an outlier among the baleen whales in that it has been named after a person, a decision that seems at odds with its small and well-defined distribution (Rosel et al, 2021). Rosel et al (2021, p. 603) argued that whales in the Bryde's complex tend to have common names associated with people involved in their discovery.…”