Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal flat ecosystems are as extensive globally as mangroves, covering at least 127,921 km2 (49,391 sq mi) of the Earth's surface. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries; they are also seen in freshwater lakes and salty lakes alike, wherein many rivers and creeks end. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of estuarine silts, clays and aquatic animal detritus. Most of the sediment within a mudflat is within the intertidal zone, and thus the flat is submerged and exposed approximately twice daily.
Callinectes sapidus, the blue crab, Atlantic blue crab, or regionally as the Maryland blue crab, is a species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico, and introduced internationally.
Mangrove crabs are crabs that live in and around mangroves. They belong to many different species and families and have been shown to be ecologically significant by burying and consuming leaf litter. Mangrove crabs have a variety of phylogenies because mangrove crab is an umbrella term that encompasses many species of crabs. Two of the most common families are sesarmid and fiddler crabs. They are omnivorous and are predated on by a variety of mammals and fish. They are distributed widely throughout the globe on coasts where mangroves are located. Mangrove crabs have wide variety of ecological and biogeochemical impacts due to the biofilms that live in symbiosis with them as well as their burrowing habits. Like many other crustaceans, they are also a human food source and have been impacted by humans as well as climate change.
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, 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 seastars, 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.
Scylla paramamosain is a mud crab commonly consumed in Southeast Asia.
Portunus pelagicus, also known as the flower crab, blue crab, blue swimmer crab, blue manna crab or sand crab is a species of large crab found in the Indo-Pacific, including off the coasts of Indonesia, Malaysia, Cambodia, Thailand, the Philippines, and Vietnam; and in the intertidal estuaries around most of Australia and east to New Caledonia.
Hemigrapsus sexdentatus, also called the “common rock crab” or “common shore crab,” is a marine crab indigenous to the southern shores of New Zealand. This crab is a member of the Varunidae family in the order Decapoda.
Hemigrapsus crenulatus, the hairy-handed crab or papaka huruhuru, is a marine crab of the family Varunidae, endemic to the New Zealand coast, although a taxon in Chile may be conspecific. It is an intertidal species with semi-terrestrial tendencies. They are named by their characteristic setae, or patches of thick hair, on the chelipeds and legs. They can range from green to brown in coloration. Adult crabs are generally 2–4 cm (0.8–1.6 in) wide at the carapace, although the smallest mature crabs can be around just 1 cm (0.4 in) wide. and are able to survive and reproduce in environments of widely varying salinities.
Ovalipes catharus, commonly known as paddle crab and Māori: pāpaka, is a species of crab of the family Portunidae. It is found around the coasts of New Zealand, the Chatham Islands, and in south-eastern parts of Australia. Individuals from shallow waters, 0.1–0.5 metres (4–20 in) deep, have a carapace width of only 10–15 millimetres (0.4–0.6 in), while those from 5–15 m (16–49 ft) are 100–140 mm (3.9–5.5 in) wide.
Pagurus novizealandiae, or the New Zealand hermit crab is a hermit crab of the family Paguridae, endemic to New Zealand. Its body is up to 16 millimetres (0.63 in) wide.
Cardisoma guanhumi, also known as the blue land crab, is a species of land crab found in tropical and subtopical estuaries and other maritime areas of land along the Atlantic coast of the Americas from Brazil and Colombia, through the Caribbean and Gulf of Mexico, to the Bahamas, and north to Ponce Inlet, Florida Princess Place Preserve on the Palm Coast, and Bermuda. The species varies in colour from dark blue to brown or pale grey, and may grow to 15 centimetres (6 in) in carapace width and weigh over 500 grams (18 oz).
Cancer productus, one of several species known as red rock crabs, is a crab of the genus Cancer found on the western coast of North America. This species is commonly nicknamed the Pearl of the Pacific Northwest.
Australia has approximately 11,500 km2 of mangroves, primarily on the northern and eastern coasts of the continent. Areas where mangroves occur include the intertidal zone of tropical, subtropical and protected temperate coastal rivers, estuaries, bays and marine shorelines. Less than 1% of Australia's total forest area is mangrove forest.
The thinstripe hermit crab, Clibanarius vittatus, is a species of hermit crab in the family Diogenidae. It is found in the Caribbean Sea, the Gulf of Mexico and the western Atlantic Ocean.
The Micro Mangrove Crab (Haberma tingkok) is a species of micro-mangrove crab native to Hong Kong. It was first discovered by Stefano Cannicci from the University of Hong Kong and Peter Ng from the University of Singapore in the Ting Kok Mangrove forests in the northeast of Hong Kong and listed on the World Register of Marine Species (WoRMS) in April of 2017. It was the third species placed in the genus Haberma, which was discovered in 2002.
Cycloxanthops novemdentatus, commonly referred to as the ninetooth pebble crab, is a small crab in the family Xanthidae.
Armases cinereum, also known as the squareback marsh crab or wharf crab, is a species of crab in the family Sesarmidae. The wharf crab is a small crab that is dark brown to muddy in color, which allows it to blend in with its usual surroundings. It is found on the Atlantic southeastern coast, down into the Gulf of Mexico. It is an omnivore and is prevalent in marshy coastal environments along the Southwestern Atlantic.
Scylla olivacea, commonly known as the orange mud crab, is a commercially important species of mangrove crab in the genus Scylla. It is one of several crabs known as the mud crab and is found in mangrove areas from Southeast Asia to Pakistan, and from Japan to northern Australia. Along with other species in the genus Scylla, it is widely farmed in aquaculture using wild-caught stocks. They can be differentiated from other species of Scylla by having blunted spines on the dorsal distal corner of the palm (propodus) of the claw, and by the rounded frontal lobe spines with shallow separations in between the eyes.
Helopgrapsus haswellianus or Haswell’s shore crab, is the sole species of crab in the genus Helograpsus. It lives in river mouths and bays on the eastern coast of Australia. The carapace is strongly convex with one distinct notch behind the eye. Adult males have larger claws than adult females. The carapace is olive, dark slate grey or reddish. Claws of adult males are orange-yellow. Carapace size is up to 30 mm wide. The orange color is stronger when these crabs live in habitat with lower pollution levels.
