NOAA:  Close encounters of the crabby kind! 
Squat lobster, seen in 2011 during the Okeanos Explorer Galápagos Rift Expedition.  In 1977, scientists discovered deep-sea hydrothermal vents and associated organisms on the Galápagos Rift, profoundly changing our view of the deep sea and revolutionizing the biological and Earth sciences. Our 2011 expedition provided scientists, engineers, and the public with an opportunity to explore unseen areas and revisit the rift sites that changed our view of life on Earth. Here’s a summary of all that was accomplished: 
NOAA Ocean Explorer

NOAA:  Close encounters of the crabby kind!

Squat lobster, seen in 2011 during the Okeanos Explorer Galápagos Rift Expedition.

In 1977, scientists discovered deep-sea hydrothermal vents and associated organisms on the Galápagos Rift, profoundly changing our view of the deep sea and revolutionizing the biological and Earth sciences. Our 2011 expedition provided scientists, engineers, and the public with an opportunity to explore unseen areas and revisit the rift sites that changed our view of life on Earth.

Here’s a summary of all that was accomplished:

NOAA Ocean Explorer

Asian tiger shrimp (Peneaus monodon)
Native to Indo-Pacific, Asian, and Australian waters, Asian tiger shrimp are now found along the Atlantic Bight and Gulf coasts of the United States. Known for their distinctive black stripes, this invasive species has a voracious appetite, feeding on native shrimp, bivalves, crustaceans, and fish. 
Scientists are exploring what effect they might have on native ecosystems: 
READ MORE. 
photo: David Knott, Southeastern Regional Taxonomic Center

Asian tiger shrimp (Peneaus monodon)

Native to Indo-Pacific, Asian, and Australian waters, Asian tiger shrimp are now found along the Atlantic Bight and Gulf coasts of the United States. Known for their distinctive black stripes, this invasive species has a voracious appetite, feeding on native shrimp, bivalves, crustaceans, and fish.

Scientists are exploring what effect they might have on native ecosystems:

READ MORE.

photo: David Knott, Southeastern Regional Taxonomic Center

dendroica

astronomy-to-zoology:

Calappa calappa

Sometimes known as the Smooth Crab or Red-spotted Box Crab Calappa calappa is a species of Calappid crab which boasts a large Indo-Pacific distribution. C. calappa is noted for its dome like appearance which it shares with other calappid crabs. Calappa calappa is chiefly nocturnal and will forage at night for clams and other molluscs which are broken open with its large chelae. 

Classification

Animalia-Arthropoda-Crustacea-Malacostraca-Decapoda-Brachyura-Calappidae-Calappa-C. calappa

Images: B kimmel and Hectonichus

astronomy-to-zoology

astronomy-to-zoology:

Red Reef Crab (Atergatis subdentatus)

Also known as the dark-finger coral crab or eyed coral crab, the red reef crab is a species of “mud crab” (Xanthidae) which occurs around the waters of Japan and surrounding areas. True to their names red reef crabs typically inhabit coral reefs and rocky beaches where it feeds on a variety of sessile and slow invertebrates. 

Classification

Animalia-Arthropoda-Crustacea-Malacostraca-Decapoda-Brachyura-Xanthidae-Atergatis-A. subdentatus

Images: Dr. Dwayne Meadows and Palmfly

mucholderthen

biovisual:

Giant Hermit Crab (Petrochirus diogenes)
Inhabiting an ~300 mm [~12 inch] Florida Horse Conch (Triplofusus giganteus) shell

SOURCE:  EOLspecies // Photographer: Joel Wooster @ www.jaxshells.org
Lower image, also by 
Joel Wooster, taken at the Marine Discovery Center in New Smyrna Beach, Florida

Eukarya >  Animalia >  Arthropoda >  Crustacea >  Malacostraca > 
     Decapoda >  Petrochirus diogenes (Linnaeus, 1758)

Strawberry Hermit Crab Beach Frenzy! Howland Island National Wildlife Refuge, in the South Pacific, is home to large numbers of the strawberry hermit crab (Coenobita perlatus). This large biomass of land crabs plays a dominant role in terrestrial food webs on the island where they consume a wide variety of organic matter. The Refuge is a part of the Pacific Remote Islands Marine National Monument. Learn more about how the monument and refuge protect fish and wildlife: Howland Island NWRPhoto credit: C. Eggleston

Strawberry Hermit Crab Beach Frenzy!

Howland Island National Wildlife Refuge, in the South Pacific, is home to large numbers of the strawberry hermit crab (Coenobita perlatus). This large biomass of land crabs plays a dominant role in terrestrial food webs on the island where they consume a wide variety of organic matter.

The Refuge is a part of the Pacific Remote Islands Marine National Monument. Learn more about how the monument and refuge protect fish and wildlife: Howland Island NWR

Photo credit: C. Eggleston

The Arctic shipping boom - a bonanza for invasive exotic species
by Natasha Geiling
As the Arctic warms and its ice melts, growing numbers freight ships are reaping big savings from the ‘Arctic short cut’. But this is creating a huge risk of invasive species spreading in ballast water and on hulls - disrupting both Arctic and temperate ecosystems.
… cargo isn’t the only thing that they’re (ships) transporting: some marine biologists worry that ships carting cargo through the Arctic’s newly opened waterways are introducing invasive species to the area - and bringing invasive species to some of America’s most important ports…
(read more: The Ecologist)
photo: Arctic Red king crab, Paralithodes camtschaticus, is causing ecological havoc as it devours its way down Norway’s coast. It can reach a leg-span of 1.8m. Photo: National Oceanic and Atmospheric Administration 

The Arctic shipping boom - a bonanza for invasive exotic species

by Natasha Geiling

As the Arctic warms and its ice melts, growing numbers freight ships are reaping big savings from the ‘Arctic short cut’. But this is creating a huge risk of invasive species spreading in ballast water and on hulls - disrupting both Arctic and temperate ecosystems.

… cargo isn’t the only thing that they’re (ships) transporting: some marine biologists worry that ships carting cargo through the Arctic’s newly opened waterways are introducing invasive species to the area - and bringing invasive species to some of America’s most important ports…

(read more: The Ecologist)

photo: Arctic Red king crab, Paralithodes camtschaticus, is causing ecological havoc as it devours its way down Norway’s coast. It can reach a leg-span of 1.8m. Photo: National Oceanic and Atmospheric Administration 

“But it didn’t really make sense,” according to doctoral research student Hanne Thoen at the University of Queensland in Brisbane, Australia, “as you really don’t need that many photoreceptors to see color and discriminate well.”

It’s a lovely thought that a glass-punching, rainbow-colored crustacean could have sensory and aesthetic capabilities beyond our wildest dreams. Yet mathematical models predict that even a so-called “ideal system” for color vision would need no more than seven photoreceptors, tops. Beyond the questionable “need” for twelve photoreceptors, “such a large number of photoreceptors would also require a large amount of processing power” for a shrimp brain to encode color like the rest of the animal kingdom—a brain whose complexity we are only beginning to explore, Thoen said…

palaeopedia
palaeopedia:

The giant Isopod, Bathynomus giganteus (1879)
Phylum : ArthropodaSubphylum : CrustaceaClass : MalacostracaOrder : IsopodaSuborder : CymothoidaFamily : CirolanidaeGenus : Bathynomus (- about 16 other species)Species : B. giganteus
Least concern
50 cm long and 1,4 kg (size)
Gulf of Mexico (map)
B. giganteus reaches an average length between 19 and 36 centimetres, with a maximum weight and length of approximately 1.7 kilograms and 76 centimetres respectively. Giant isopods are a good example of deep-sea gigantism. Though most other species of Bathynomus apparently are smaller, they are nevertheless far larger than the “typical” isopods that range in size from 1 to 5 centimetres.
Their morphology resembles that of their terrestrial cousin, the woodlouse: their bodies are dorso-ventrally compressed, protected by a rigid, calcareous exoskeleton composed of overlapping segments. Like the woodlouse, they also possess the ability to curl up into a “ball”, where only the tough shell is exposed. This provides protection from predators trying to strike at the more vulnerable underside. The first shell segment is fused to the head; the most posterior segments are often fused as well, forming a “caudal shield” over the shortened abdomen (pleon). The large eyes are compound with nearly 4,000 facets, sessile and spaced far apart on the head. There are two pairs of antennae.
The uniramous thoracic legs or pereiopods are arranged in seven pairs, the first of which are modified into maxillipeds to manipulate and bring food to the four sets of jaws. The abdomen has five segments called pleonites each with a pair of biramous pleopods; these are modified into natatory legs and rami, flat respiratory structures acting as gills. The isopods are a pale lilac in colour.

palaeopedia:

The giant Isopod, Bathynomus giganteus (1879)

Phylum : Arthropoda
Subphylum : Crustacea
Class : Malacostraca
Order : Isopoda
Suborder : Cymothoida
Family : Cirolanidae
Genus : Bathynomus (- about 16 other species)
Species : B. giganteus

  • Least concern
  • 50 cm long and 1,4 kg (size)
  • Gulf of Mexico (map)

B. giganteus reaches an average length between 19 and 36 centimetres, with a maximum weight and length of approximately 1.7 kilograms and 76 centimetres respectively. Giant isopods are a good example of deep-sea gigantism. Though most other species of Bathynomus apparently are smaller, they are nevertheless far larger than the “typical” isopods that range in size from 1 to 5 centimetres.

Their morphology resembles that of their terrestrial cousin, the woodlouse: their bodies are dorso-ventrally compressed, protected by a rigid, calcareous exoskeleton composed of overlapping segments. Like the woodlouse, they also possess the ability to curl up into a “ball”, where only the tough shell is exposed. This provides protection from predators trying to strike at the more vulnerable underside. The first shell segment is fused to the head; the most posterior segments are often fused as well, forming a “caudal shield” over the shortened abdomen (pleon). The large eyes are compound with nearly 4,000 facets, sessile and spaced far apart on the head. There are two pairs of antennae.

The uniramous thoracic legs or pereiopods are arranged in seven pairs, the first of which are modified into maxillipeds to manipulate and bring food to the four sets of jaws. The abdomen has five segments called pleonites each with a pair of biramous pleopods; these are modified into natatory legs and rami, flat respiratory structures acting as gills. The isopods are a pale lilac in colour.