Humpback whale lunge feeding on Antarctic krill, with mouth open and baleen visible.  The humbpack's throat grooves are seen as its pleated throat becomes fully distended as the whale fills its mouth with krill and water.  The water will be pushed out, while the baleen strains and retains the small krill, Megaptera novaeangliae, Gerlache Strait

Humpback Whale Lunge Feeding On Antarctic Krill, Gerlache Strait

Humpback whale lunge feeding on Antarctic krill, with mouth open and baleen visible.  The humbpack's pink throat grooves are seen as its pleated throat becomes fully distended as the whale fills its mouth with krill and water.  The water will be pushed out, while the baleen strains and retains the small krill, Megaptera novaeangliae, Gerlache Strait

Humpback whale lunge feeding on Antarctic krill, Antarctic Peninsula.

A blue whale eating krill.  This blue whale is seen feeding and surfacing amid krill with its throat fully engorged with krill and water.  It will push the water back out with its tongue, trapping the krill in its baleen which acts like a filter. Aerial photo, Baja California, Balaenoptera musculus

Blue whale eating krill, aerial photo, the mouth and throat pleats are engorged with water and krill. Aerial photo, Baja California.

The closeup photo is a specimen of Thysanoessa spinifera, one of the euphausiids commonly known as krill, measured about one-half inch long. It was photographed alive after being collected from a cloud of krill observed at the ocean surface near Islas Coronado (Mexico) in July 1999. Blue whales were in the area and surface feeding on other large krill swarms throughout the day. The center photograph depicts one of these blue whales with its throat engorged after taking a mouthful of water. It will push the water back out of its mouth with its tongue, trapping the krill among its many plates of baleen. Such feeding is sometimes seen in Baja California and northward along California's coast to Oregon. Large flocks of pelicans and gulls were also surface feeding on the krill. According to Jaime Gomez Gutierrez of Oregon State University, who provided the identification, Thysanoessa spinifera is characterized by its large rostrum, bilobulate eyes, and two prominent spines in the fourth and fifth abdominal segment. It lives in coastal waters associated with cool upwelling waters. Along with Euphausia pacifica (no rostrum, spherical eye, no spines in the abdomen and a prominent spine in the lateral part of the caparace), Thysanoessa spinifera is the most important food item of the blue whale because of their relatively large size (adults to 1.5 - 3 cm) and their presence in huge swarms.

Krill.  Likely Euphausia pacifica. A thin cloud of pink krill gathers at the ocean surface, where it is likely to be preyed upon by sharks, fish, birds and whales, San Diego, California

A cloud of tiny pink krill gathers at the ocean surface, where it is likely to be preyed upon by sharks, fish, birds and whales. Likely Euphausia pacifica.

Krill.  A thin cloud of pink krill gathers at the ocean surface, where it is likely to be preyed upon by sharks, fish, birds and whales.  Likely Euphausia pacifica, San Diego, California

Euphausia pacifica, a cloud of krill underwater.

Krill, Baja California (Pacific Ocean), Thysanoessa spinifera

Blue whales residing off California eat tons (literally) of tiny euphasiid krill, such as Thysanoessa spinifera.

Brown pelicans feeding on krill, Pelecanus occidentalis, Coronado Islands (Islas Coronado)

Brown Pelican, Coronado Islands