Different transformations underlie blowhole and nasal passage development in a toothed whale (Odontoceti: Stenella attenuata ) and a baleen whale (Mysticeti: Balaenoptera physalus )

AbstractDocumenting marine mammal strandings provides important information needed to understand the occurrence and distribution patterns of species. Here, we report on strandings of cetaceans on the Pacific (n = 11) and Caribbean (n = 2) coasts of Nicaragua, documented opportunistically from 2014 to 2021. Strandings included three species of baleen whale (blue whale Balaenoptera musculus, Bryde’s whale Balaenoptera edeni, humpback whale Megaptera novaeangliae) and five species of toothed whale (dwarf sperm whale Kogia sima, Guiana dolphin Sotalia guianensis, pantropical spotted dolphin Stenella attenuata, spinner dolphin Stenella longirostris, Cuvier’s beaked whale Ziphius cavirostris). These are the first published accounts of blue whales, Bryde’s whales, dwarf sperm whales, and Cuvier’s beaked whales in Nicaraguan waters. Limited resources and the advanced decomposition of animals prevented necropsies in most cases, the identification of the causes of mortality in all cases, and the species identification of two dolphins. Information derived from these stranding events offers new insights into the occurrence of marine mammals on the Pacific and Caribbean coasts of Nicaragua and Central America.

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The nose of the sperm whale: overviews of functional design, structural homologies and evolution

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315414001118 ◽

2014 ◽

Vol 96 (4) ◽

pp. 783-806 ◽

Cited By ~ 14

Author(s):

Stefan Huggenberger ◽

Michel André ◽

Helmut H. A. Oelschläger

Keyword(s):

Sperm Whale ◽

Pulse Generation ◽

Nasal Passage ◽

Generation Process ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Acoustic Window ◽

Deep Diving ◽

Toothed Whale ◽

Fat Bodies

The hypertrophic and much elongated epicranial (nasal) complex of sperm whales (Physeter macrocephalus) is a unique device to increase directionality and source levels of echolocation clicks in aquatic environments. The size and shape of the nasal fat bodies as well as the peculiar organization of the air sac system in the nasal sound generator of sperm whales are in favour of this proposed specialized acoustic function. The morphology of the sperm whale nose, including a ‘connecting acoustic window’ in the case and an anterior ‘terminal acoustic window’ at the rostroventral edge of the junk, supports the ‘bent horn hypothesis’ of sound emission. In contrast to the laryngeal mechanism described for dolphins and porpoises, sperm whales may drive the initial pulse generation process with air pressurized by nasal muscles associated with the right nasal passage (right nasal passage muscle, maxillonasolabialis muscle). This can be interpreted as an adaptation to deep-diving and high hydrostatic pressures constraining pneumatic phonation. Comparison of nasal structures in sperm whales and other toothed whales reveals that the existing air sac system as well as the fat bodies and the musculature have the same topographical relations and thus may be homologous in all toothed whales (Odontoceti). This implies that the nasal sound generating system evolved only once during toothed whale evolution and, more specifically, that the unique hypertrophied nasal complex was a main driving force in the evolution of the sperm whale taxon.

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Atlas of Marine Mammal Distribution and Abundance in Mexican Waters

10.26359/epomex.cemie022020 ◽

2020 ◽

Author(s):

Gisela Heckel ◽

◽

M.G. Ruiz Mar ◽

Y. Schramm ◽

U. Gorter

Keyword(s):

Marine Mammals ◽

Sea Otter ◽

Baleen Whale ◽

Sea Lion ◽

Sea Otters ◽

Cetacean Species ◽

Sea Lions ◽

The World ◽

Toothed Whale ◽

Mammal Distribution

Marine mammals are a group of charismatic megafauna, capable of awakening fascination in most people, which makes them especially visible when natural resources or ecosystems are exploited, as is the case with the generation of energy using the sea. There are 131 species of marine mammals in the world, including whales, dolphins, sea lions, seals, walruses, sea otters, polar bears, manatees and dugongs. Mexico’s marine environment is megadiverse, with 38 cetacean species (eight mysticeti or baleen whale species, 30 odontoceti or toothed whale species, dolphins and porpoises), four pinnipeds (two seal species and two sea lion species), one sea otter sub-species and one manatee subspecies (

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Tracing the spatio-temporal dynamics of endangered fin whales (Balaenoptera physalus) within baleen whale (Mysticeti) lineages: a mitogenomic perspective

Genetica ◽

10.1007/s10709-017-9988-4 ◽

2017 ◽

Vol 145 (6) ◽

pp. 603-612

Author(s):

Jihyun Yu ◽

Bo-Hye Nam ◽

Joon Yoon ◽

Eun Bae Kim ◽

Jung Youn Park ◽

...

Keyword(s):

Temporal Dynamics ◽

Baleen Whale ◽

Balaenoptera Physalus ◽

Fin Whales ◽

Spatio Temporal

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Bauplan of a Blowhole: Testing a Developmental Model for Nasal Passage Reorientation in Echolocating Whales (Odontoceti) and a Baleen Whale (Mysticeti)

The FASEB Journal ◽

10.1096/fasebj.2021.35.s1.04523 ◽

2021 ◽

Vol 35 (S1) ◽

Author(s):

Rachel Roston ◽

V. Louise Roth

Keyword(s):

Developmental Model ◽

Nasal Passage ◽

Baleen Whale

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The Existence of different Fin Whale, Balaenoptera Physalus, populations in South Atlantic waters.

Bijdragen tot de Dierkunde ◽

10.1163/26660644-05401009 ◽

1984 ◽

Vol 54 (1) ◽

pp. 127-138

Author(s):

J.G. van Beek ◽

W.L. van Utrecht

Keyword(s):

Southern Hemisphere ◽

South Atlantic ◽

Baleen Whale ◽

Balaenoptera Physalus ◽

Fin Whale ◽

Feeding Grounds

The southern hemisphere has been divided into six Areas for baleen whale management purposes. It was assumed that of the different baleen whale species one population lives in each Area. However, evidence exists which suggests that different Fin Whale populations intermingle on the feeding grounds of anArea. This obviously would have implications with respect to Fin Whale management.

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