Pachygrapsus crassipes | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Malacostraca |
Order: | Decapoda |
Suborder: | Pleocyemata |
Infraorder: | Brachyura |
Family: | Grapsidae |
Genus: | Pachygrapsus |
Species: | P. crassipes |
Binomial name | |
Pachygrapsus crassipes Randall, 1840 | |
Pachygrapsus crassipes, the striped shore crab or lined shore crab, is a small crab found on both rocky and hard-mud soft seashores of the northeastern and northwestern Pacific Ocean. In North America, this species occurs from central Oregon, south through California to near Ensenada, Baja California, Mexico. There is an isolated population with a wide range disjunction at Bamfield on Vancouver Island, Canada. [1] The western Pacific population, including both Korea and Japan is isolated with a divergence time from the eastern Pacific population estimated between 0.8 and 1.2 Mya. [1]
Typically, this crab will have a brown/purple or black carapace with green stripes. Its carapace is square and can reach 4 to 5 cm in size. The claws are red/purple with a mottled and striped pattern on the upper surface, and whitish-grayish on the lower surface, while its legs are purple and green with a similar mottled appearance. [2]
It will spend over half of its time on land. It will purposely submerge to wet its gills but can sustain itself on land for up to ~70 hours. [3] [4] They enjoy hiding in small crevices within rock, but will emerge at night when there is less danger of predation. [4] This opportunistic predator's diet consists of green algae, red algae, brown seaweed, diatoms, worms, mussels, small decaying organisms, limpets, snails, flies, hermit crabs, seaweed, isopods, and sometimes even each other when the lesser crab has just finished molting. [3] [4] [5] They have preference to small mussels over larger mussels over seaweed. [5] Although there will be aggressive intraspecies competition over food, they do not keep a standard territory to defend. [4] [6] Generally they are eaten by seagulls, octopuses, rats, raccoons, and humans, but are vulnerable to other organisms especially during their juvenile stages. [3] [4]
Hunting strategies will differ based on their habitat. On rocky shores they will hunt more often than they forage, and under the cover of night, whilst in intertidal pools they will focus more on herbivory even during daytime hours. [6] Intraspecies conflicts occur more out of defense in close captivity out of water, whilst in water it occurs more out of aggression. [6] Over time a social hierarchy for the species within its habitat will form. [6]
The dog whelk, dogwhelk, or Atlantic dogwinkle is a species of predatory sea snail, a carnivorous marine gastropod in the family Muricidae, the rock snails.
A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. These pools typically range from a few inches to a few feet deep and a few feet across. Many of these pools exist as separate bodies of water only at low tide, as seawater gets trapped when the tide recedes. Tides are caused by the gravitational pull of the sun and moon. A tidal cycle is usually about 25 hours and consists of one or two high tides and two low tides.
The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various species of life, such as sea stars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the littoral zone or seashore, although those can be defined as a wider region.
Carcinus maenas is a common littoral crab. It is known by different names around the world. In the British Isles, it is generally referred to as the shore crab, or green shore crab. In North America and South Africa, it bears the name European green crab.
Ecological facilitation or probiosis describes species interactions that benefit at least one of the participants and cause harm to neither. Facilitations can be categorized as mutualisms, in which both species benefit, or commensalisms, in which one species benefits and the other is unaffected. This article addresses both the mechanisms of facilitation and the increasing information available concerning the impacts of facilitation on community ecology.
Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied, the broadest of classifications being based on substrates—rocky shore and soft bottom communities.
The Jonah crab is a marine brachyuran crab that inhabits waters along the east coast of North America from Newfoundland to Florida. Jonah crabs possess a rounded, rough-edged carapace with small light spots, and robust claws with dark brown-black tips. The maximum reported carapace width for males is 8.7 in (222 mm), while females rarely exceed 5.9 in (150 mm). It is the closest relative to the European brown crab in the Western Atlantic.
The Smooth Shore Crab is a marine large-eyed crab of the family Grapsidae, found in New Zealand and the Juan Fernández Islands of Chile.
Postelsia palmaeformis, also known as the sea palm or palm seaweed, is a species of kelp and classified within brown algae. It is the only known species in the genus Postelsia. The sea palm is found along the western coast of North America, on rocky shores with constant waves. It is one of the few algae that can survive and remain erect out of the water; in fact, it spends most of its life cycle exposed to the air. It is an annual, and edible, though harvesting of the alga is discouraged due to the species' sensitivity to overharvesting.
Notomithrax ursus, known as the hairy seaweed crab, is a spider crab of the family Majidae.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
The purple shore crab is a common crab of the family Varunidae that is indigenous to the west coast of United States, Canada, and Mexico. H. nudus was first described in 1847 by Adam White, and in 1851, James Dwight Dana formally classified the species. H. nudus is a small, amphibious crab that is similar physically and behaviorally to Pachygrapsus crassipes and Hemigrapsus oregonensis. The purple shore crab is generally a dark purple color with olive green, red, and white spots. Mating season for H. nudus begins in mid-winter and larval crabs undergo 5 zoeal stages and a juvenile stage. Adult crabs mainly feed on algae but will occasionally scavenge other animals. H. nudus prefers inter-tidal and sub-tidal zones, and it can oftentimes be found sheltering under rocks or other debris. H. nudus demonstrates complex compensatory mechanisms to counteract fluctuating salinity and water oxygen concentrations, permitting it to live in a variety of different environments.
Hemigrapsus oregonensis is a small shore crab of the family Varunidae; formerly classified under the family Grapsidae. It is known under several common names, including yellow shore crab, hairy shore crab, green shore crab, mud-flat crab, bay shore crab and Oregon shore crab. Despite its common name, the crab actually has a wide variety of coloration. It is found along the West Coast of the United States and Canada, specifically along shorelines and similar geographical areas. In 2009, H. oregonensis was included on a list of animals petitioning for the endangered species label, but there was not enough scientific information available for it to be considered as such, so it remains unevaluated to the present day.
Seashore wildlife habitats exist from the Tropics to the Arctic and Antarctic. Seashores and beaches provide varied habitats in different parts of the world, and even within the same beach. Phytoplankton is at the bottom of some food chains, while zooplankton and other organisms eat phytoplankton. Kelp is also autotrophic and at the bottom of many food chains. Coastal areas are stressed through rapid changes, for example due to tides.
Pilumnus hirtellus, the bristly crab or hairy crab, is a species of European crab. It is less than 1 inch (25 mm) long and covered in hair. It lives in shallow water and feeds on carrion.
Pachygrapsus marmoratus is a species of crab, sometimes called the marbled rock crab or marbled crab, which lives in the Black Sea, the Mediterranean Sea and parts of the Atlantic Ocean. It is dark violet brown, with yellow marbling, and with a body up to 36 millimetres (1.4 in) long. A semiterrestrial omnivore, it feeds on algae and various animals including mussels and limpets.
Pugettia producta, known as the northern kelp crab or shield-backed kelp crab, is a species of crab in the family Epialtidae.
Stichaster australis, the reef starfish, is a species of starfish found in the shallow waters of the rocky intertidal of New Zealand. Typically, the animal is endemic to the west coast shores of the North and South Islands, where wave action is increased. They do not usually inhabit ecosystems that have reduced wave action and calm conditions as they prefer a higher-energy environment. These marine invertebrates range in color from pink to purple, but can also be orange. They typically have eleven arms, but sometimes they may have either ten or twelve. As full-grown adults, they are 8 to 10 cm in diameter.
Petrolisthes eriomerus is a species of marine porcelain crab found in the eastern Pacific Ocean. It is commonly known as the flattop crab. It is a flattened, rounded animal, with a carapace up to 20 mm (0.8 in) across. It is a filter feeder, and also sweeps food from rocks.
Pollicipes polymerus, commonly known as the gooseneck barnacle or leaf barnacle, is a species of stalked barnacle. It is found, often in great numbers, on rocky shores on the Pacific coasts of North America.