Dall’s Porpoise Skull Replica

Description

Dall’s Porpoise Skull Replica measures 11.6 inches. Dall’s porpoise skull replica is museum-quality polyurethane resin cast from California Academy of Sciences specimen. 2-part skull (separate cranium & mandible). 1:1 scale. Made in USA.

Dall’s porpoise or Phocoenoides dalli is a species of porpoise endemic to the North Pacific. It is the largest of porpoises and the only member of the genus Phocoenoides. The species is named after American naturalist W. H. Dall.

Dall’s porpoise is the only member of the genus Phocoenoides. The dalli-and truei-types were initially described as separate species in 1911, but later studies determined that the available evidence only supported the existence of one species.

Currently, these two color morphs are recognized as distinct subspecies, Dall’s porpoise (Phocoenoides dalli dalli) and True’s porpoise (Phocoenoides dalli truei).

Dall’s porpoise can be easily distinguished from other porpoises and cetacean species within their range. They have a wide, robust body, a comparatively tiny head, and no distinguished beak.

Their flippers are positioned at the front of the body and a triangular dorsal fin sits mid-body. Patterns of coloration are highly variable, but Dall’s porpoises are mostly black, have white to grey patches on the flank and belly, and frosting on the dorsal fin and trailing-edge of the fluke.

They are the largest porpoise species, growing up to 7.5 ft. in length and weighing between 370 and 490 lb.

Sexual dimorphism is apparent in body size and shape, with mature males being larger, developing a deeper caudal peduncle, and having a dorsal fin that’s significantly angled forward in comparison to a female’s.

Two colormorphs have been identified: the dalli-type and truei-type. The truei-type, found only in the western Pacific, has a white belly patch that extends farther forward across the body than that of the dalli-type.

Dall’s porpoises are limited to the North Pacific: in the east from California to the Bering Sea and Okhotsk Sea, and in the west down to the Sea of Japan. They have been sighted as far south as Scammon’s Lagoon in Baja California when water temperature was unseasonably cold.

Dall’s porpoise are opportunistic, hunting a variety of surface and mid-water species. Common prey are mesopelgic fish, such as myctophids, and gonatid squid.

Scientific Classification:

• Kingdom: Animalia
• Phylum: Chordata
• Class: Mammalia
• Order: Artiodactyla
• Infraorder: Cetacea
• Family: Phocoenidae
• Genus: Phocoenoides
• Species: P. dalli
• Binomial name: Phocoenoides dalli (True, 1885
• Conservation Status: Least Concern (IUCN 3.1), CITES Appendix II

Compare the Dall’s Porpoise skull to the common harbour porpoise skull, its smaller same water relative from the North Pacific.