Jan 7, 2009

Endangered Species - Invertebrates

Endangered Invertebrates

Invertebrates account for 97 percent of all animal species. Insects, spiders, crustaceans, squid, snails, octopi, jellyfish, sponges, flatworms, roundworms, segmented worms, starfish, sea urchins, sea cucumbers and sea mats are all major invertebrate phylums or classes.

Invertebrate species, especially in locations like the Amazon Basin, are going extinct at an alarming rate. Over half of those evaluated are now listed as threatened or endangered by the IUCN, with crustaceans accounting for the highest percentage. Habitat loss seems to be the major reason invertebrate species continue to vanish.

The American burying beetle is so named because of its habit of burying its food, which consists of just about any dead animal. As a scavenger, it spends much of its time clearing carcasses off the forest floor. For this reason, it is a critical part of the North American ecosystem. Historically, this species could be found in woodland areas from New England to the Rocky Mountains. Today, it is found in only a handful of states due to declining prey species and loss of habitat.

IUCN Status: Critically Endangered
USFWS Status: Endangered
Major Threats: Habitat loss and declining prey species
Habitat: Maritime shrub thickets, coastal moraine grasslands and open pasture
Location: Eastern Oklahoma and Block Island, Rhode Island
Diet: Carrion

Like their dragonfly relatives, damselflies are highly effective predators and expert aerial acrobats. They have large eyes and wings that fold back when the insect is at rest. A native of the Eastern Cape of South Africa, the basking malachite damselfly was nearly extinct at the start of the 21st century due to environmental pollution and alterations of its habitat by non-native species. Conservation activities are currently underway to save this species.

IUCN Status: Endangered
Major Threats: Environmental pollution and habitat alteration by non-native species
Habitat: Clear, shallow, rocky streams with overhanging grasses
Location: Eastern Cape of South Africa
Diet: Insects

With a wingspan of about 2.5 inches, the callippe silverspot butterfly is a medium-sized butterfly. Its wings are a dazzling pattern of black spots and lines on a brownish-gold background with the base of the wing being very hairy. The callippe silverspot lives in the grasslands surrounding the San Francisco Bay Area of California. It is threatened by loss of habitat.

USFWS Status: Endangered
Major Threat: Habitat loss
Habitat: Grasslands
Location: San Francisco Bay Area of California
Diet: Nectar

About one-third of the insects on earth are beetles. They occur in most terrestrial and freshwater habitats, and make up about 360,000 different species. Ground beetles are elongated and flattened beetles that live beneath stones and plant material on the ground. The delta green ground beetle is a bright green species that once occurred in the temporary pools throughout California's Central Valley but is now confined to a small region in Northern California.

IUCN Status: Critically Endangered
Major Threat: Agricultural development
Habitat: Vernal pool habitats
Location: Solano County in Northern California
Diet: Mainly springtails (tiny, wingless insects)

The Dlinza Forest pinwheel is a snail that undoubtedly gets its name from the whorl of bristles emanating from its outer shell. It is found only in a small patch of the Dlinza Forest of South Africa, which comprises about 250 hectares. The forest is protected; however, it is a very small location within a major urban area, and there is concern that this species cannot survive.

IUCN Status: Critically Endangered
Major Threat: Extremely small range
Habitat: Coastal scarp forest and damp swampy areas
Location: Dlinza Forest in South Africa
Diet: Unknown

Moths are closely related to butterflies, but are usually drab whereas butterflies are brightly colored. This is not true of the fabulous green sphinx moth, an animal that is named for its bright green thorax and orange antennae. In the late 1990s, this species was thought to be extinct. However, there have been sightings of the fabulous green sphinx moth in recent years on the island of Kauai in Hawaii, the only place where this species occurs.

IUCN Status: Endangered
Major Threats: Collection and habitat destruction
Habitat: Uknown
Location: Hawaii's Kauai island
Diet: Unknown

The fanshell is a freshwater mollusk found in the rivers and streams of the Midwest and eastern United States. Their larvae attach themselves to the gills of fish, where they remain until they grow into juveniles with shells of their own. Adult fanshells bury themselves in sand or gravel with only their siphons exposed to the current. Dam and reservoir construction as well as sand and gravel mining have contributed to the destruction of much of the fanshell's habitat.

IUCN Status: Critically Endangered
USFWS Status: Endangered
Major Threat: Habitat destruction
Habitat: Streams and rivers
Location: Midwest and eastern United States
Diet: Likely detritus, diatoms, phytoplankton and zooplankton

Freshwater crayfish are lobster-like animals with powerful claws on their front legs. The giant freshwater crayfish is the world's largest known freshwater invertebrate. It lives in the mud and silt on the bottom of streams, rivers, and lakes in Tasmania and mainland Australia. Once abundant, their numbers have been reduced by fishing pressure and environmental pollution.

IUCN Status: Endangered
Major Threats: Fishing pressure and environmental pollution
Habitat: Mud and silt on bottoms of streams, rivers and lakes
Location: Tasmania and mainland Australia
Diet: Mainly decaying wood

The Illinois cave amphipod is a tiny crustacean found in the dark zones of cave streams in Illinois. It is light blue-gray but may appear translucent. This species is considered very important because its health is an indicator of groundwater quality in the area where it occurs. It is currently threatened by groundwater contamination as well as human disturbance within Illinois caves.

IUCN Status: Endangered
USFWS Status: Endangered
Major Threat: Groundwater contamination and human disturbance
Habitat: Dark zones of cave streams
Location: Illinois
Diet: Dead animals and plants

The lotus blue butterfly is a beautiful insect species with azure wings fringed in white scales along the outer margin. It is known to occur only in the coastal bogs of Northern California. There have been no sightings of this species for more than 20 years, and they may already be extinct. Threats to the lotus blue butterfly are not well understood but are likely to include loss of bog habitat.

USFWS Status: Endangered
Major Threat: Loss of bog habitat
Habitat: Coastal bogs
Location: Northern California
Diet: Nectar