Alaska Nature: Invertebrates

Alaska Marine Highway
Alaska's State Flower is the "Forget-Me-Not. Forget me not flowers are very fragrant in the evening and night time, though there is little or no scent in the daytime. They can be annual or perennial plants. Their seeds are found in small, tulip shaped pods along the stem to the flower.
Ninety-five per cent of all the animal species in Alaska are invertebrate. Of course most of these invertebrates are insects and bugs. A great many types of invertebrates also exist in marine waters. The 1964 earthquake and resulting tsunami wreaked havoc on intertidal beaches and seafloor of Port Valdez, Marine plants and animals on Port Valdez beaches were destroyed by the tsunami while the earthquake deposited massive amounts of sediment on the seafloor. This caused the whole community of bottom-dwelling marine invertebrates, such as sea worms, snails and clams,  to change. Some seafloor invertebrates usually found in glacial fjords like Port Valdez, such as the sea worms Terebellides stroemi and Galathowenia oculata, virtually disappeared. Other animals took advantage of the disturbance and colonized the area. One of those animals is a family of sea worms called Capitellidae. They became unusually dominant in the region for a few years. Capitellidae are known for being highly opportunistic and tolerant of disturbance.

Abalones are marine snails.  The pinto abalone has an oval shell with 4–6 holes and can grow up to 6 inches long. The outside coloring can be red, pink, tan, or mottled. The inside of the shell is mother of pearl. The muscle is cream colored in the center, mottled orange on the sides, and darker orange at the foot. There are tentacles around the foot and a fold that may be speckled or solid brown or black. The abalone’s head has two large tentacles, eye stocks, and a rasping mouth. The pinto abalone inhabits fairly shallow areas of the coastal waters of southeast Alaska. It is known to occur from the Dixon Entrance north to Icy Straights, but fishermen have reported it west from Cape Spencer to Yakutat. Outside of Alaska, the pinto abalone is found along the Pacific coast as far south as Point Conception, California. This species of abalone requires exposure to ocean currents. They are frequently found in kelp beds and on rocky bottoms. Most occupy the sea floor from low-low tide to minus 30-40 feet.  The abundance of pinto abalone in Alaska declined sharply from 1982 to 1995. Pinto abalone are continuing to disappear in large areas of its range due to predation by sea otters.

Though more southerly states such as Colorado can claim 250 or more resident species of butterflies, at least 78 species flit around the Alaskan countryside. A few species of butterflies live only in the northern tundra. They can survive there in summer because they have become experts on making use of solar energy. By doing so, butterflies are capable of raising their body temperatures as much as 17¯C (30¯F) above ambient. Summer coolness rather than winter's cold limits the number of butterflies in the Arctic. Not having a source of heat within their bodies as mammals do, and yet needing a certain minimum body temperature in order to fly, butterflies must gain heat from their environment. In winter they are, of course, inactive but those who live over the winter in the adult stage avoid freezing damage to their body tissues by stocking up on self-manufactured antifreeze materials each fall. Some arctic butterflies survive, in larval stage, over two winters. The Arctic Eskimo Butterfly is a medium-sized brown butterfly. Its upperside of wings is orange-brown, with basal two-thirds of both wings darker, especially in males. The Arctic Eskimo Butterfly has been found at several sites in Alaska, all of them along the northern foot of theBrooks Range from near Anaktuvuk Pass to the Dalton Highway.

The red sea cucumber can grow to a length of 50 cm and a width of 5 cm, and when drained of fluids can weigh up to 500 grams. It has a soft, cylindrical body, with red-brown to yellowish leathery skin.  This species feeds on organic detritus and small organisms.. Maturity is estimated to occur between 4 and 8 years of age and the maximum age is estimated as 12 years in British Columbia.  The red sea cucumber is a common species distributed from Mexico to Southeast Alaska and has been observed at least as far west and north as the Alaska Peninsula, Aleutian Islands, and Bering Sea. The abundance of sea cucumbers in Southeast Alaska is greatest in the southern and western portions in protected bays and inlets.

Red sea urchins vary in color between a uniform red and dark burgundy and crawl slowly over the sea bottom using their spines as stilts. The red sea urchin is the largest of the sea urchins, with a maximum "test", or outer skeleton, diameter of more than 18 cm and a maximum spine length of 8 cm. The test is made up of 10 fused plates that encircle the sea urchin like the slices of an orange. In Southeast Alaska, the red sea urchin occurs primarily on rocky shorelines of the outside coast with largest concentrations in southern southeast. They can inhabit intertidal depth to up to 90 m.  In Southeast Alaska, the red sea urchin population is kept at very low levels by sea otters in many areas of the outside coasts. Sea stars are also common predators of sea urchins.

Alaska has long been known for it’s crab fisheries. King crab is perhaps the most famous and valuable of these, pound for pound, although snow crab has produced both the greatest landings and the greatest revenue in recent years. However, there are many more crab species in Alaskan waters


sea urchins abound off the coast of alsaka

king sea spider off the coast of Alaska

Sea Turtles:

Marine turtles are occasional visitors to Alaska’s Gulf Coast waters

Learn more about Alaskan turtles

Leatherbacks Green Sea Turtle
Olive Ridley Loggerhead