Crab in the context of "Polyphyletic"

Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (freshwater or marine), but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques include trawling, longlining, jigging, hand-gathering, spearing, netting, angling, shooting and trapping, as well as more destructive and often illegal techniques such as electrocution, blasting and poisoning.

The term fishing is also used more broadly to include catching aquatic animals other than fish, such as crustaceans (shrimp/lobsters/crabs), shellfish, cephalopods (octopus/squid) and echinoderms (starfish/sea urchins). The term is not normally applied to harvesting fish raised in controlled cultivations (fish farming). Nor is it normally applied to hunting aquatic mammals, where terms like whaling and sealing are used instead.

A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and long green, grass-like leaves. They produce seeds and pollen and have roots and rhizomes which anchor them in seafloor sand.

Seagrasses form dense underwater meadows which are among the most productive ecosystems in the world. They provide habitats and food for a diversity of marine life comparable to that of coral reefs. This includes invertebrates like shrimp and crabs, cod and flatfish, marine mammals and birds. They provide refuges for endangered species such as seahorses, turtles, and dugongs. They function as nursery habitats for shrimps, scallops and many commercial fish species. Seagrass meadows provide coastal storm protection by the way their leaves absorb energy from waves as they hit the coast. They keep coastal waters healthy by absorbing bacteria and nutrients, and slow the speed of climate change by sequestering carbon dioxide into the sediment of the ocean floor.

Barnacles are arthropods of the subclass Cirripedia in the subphylum Crustacea. They are related to crabs and lobsters, with similar nauplius larvae. Barnacles are exclusively marine invertebrates; many species live in shallow and tidal waters. Some 2,100 species have been described.

Barnacle adults are sessile; most are suspension feeders with hard calcareous shells, but the Rhizocephala are specialized parasites of other crustaceans, with reduced bodies. Barnacles have existed since at least the mid-Carboniferous, some 325 million years ago.

Divination is the attempt to gain insight into a question or situation by way of a magic ritual or practice. Using various methods, throughout history, diviners have been providing answers to querents by reading signs, events, or omens, often receiving insight through supernatural agencies such as spirits, gods, god-like-beings or the "will of the universe".

Divination can be seen as an attempt to organize what appears to be random, so that it provides insight into a problem or issue at hand. Some practices of divination include astrology, Tarot card reading, rune casting, tea-leaf reading, Ouija boards, automatic writing, water scrying, numerology, pendulum divination and countless more. If a distinction is made between divination and fortune-telling, divination has a more formal or ritualistic element and often contains a more social character, usually in a religious context, as seen in traditional African medicine. Fortune-telling, on the other hand, is a more everyday practice for personal purposes. Particular divination methods vary by culture and religion.

Installation art is an artistic genre of three-dimensional works that are often site-specific and designed to transform the perception of a space. Generally, the term is applied to interior spaces, whereas exterior interventions are often called public art, land art or art intervention; however, the boundaries between these terms overlap.

A gill (/ɡɪl/ ) is a specialized respiratory organ that many aquatic animals use for aquatic gas exchange, i.e. to extract dissolved oxygen from water and to excrete carbon dioxide. Branchia (pl.: branchiae, from Ancient Greek βράγχια) is the zoologists' academic name for gills.

The gills of some semi-aquatic clades (e.g. crabs, terrestrial hermit crabs and amphibious fishes), have also adapted to allow air respiration (breathing) on land provided the gills are kept moist. In some terrestrial chelicerates species (tetrapulmonates such as spiders and scorpions), their ancestral gills have evolved into fully air-breathing book lungs. In some planktivorous bony fish species (e.g. silver and bighead carps), the gills are also used as a filter feeding organ via comb-like projections called gill rakers.

In biology, being semiaquatic refers to various macro-organisms that live regularly in both aquatic and terrestrial environments. When referring to animals, the term describes those that actively spend part of their daily time in water (in which case they can also be called amphibious), or land animals that have spent at least one life stage (e.g. as eggs or larvae) in aquatic environments. When referring to plants, the term describes land plants whose roots have adapted well to tolerate regular, prolonged submersion in water, as well as emergent and (occasionally) floating-leaved aquatic plants that are only partially immersed in water.

Examples of semiaquatic animals and plants are given below.

Abdopus aculeatus is a small species of octopus in the order Octopoda. It has the common name algae octopus due to its typical resting camouflage, which resembles a gastropod shell overgrown with algae. It is small in size with a mantle around the size of a small orange (c. 7 cm or 3 inches) and arms 25 cm (10 inches) in length, and is adept at mimicking its surroundings.

A. aculeatus has been described as "the only land octopus", because it lives on beaches walking from one tidal pool to the next hunting for crabs. Many other octopuses can crawl short distances on land when necessary, but only A. aculeatus is known to do so on a routine basis.

A freshwater prawn farm is an aquaculture business designed to raise and produce freshwater prawns or shrimp for human consumption. Freshwater prawn farming shares many characteristics with, and many of the same problems as, marine shrimp farming. Unique problems are introduced by the developmental life cycle of the main species (the giant river prawn, Macrobrachium rosenbergii).

The global annual production of freshwater prawns (excluding crayfish and crabs) in 2003 was about 280,000 tons, of which China produced some 180,000 tons, followed by India and Thailand with some 35,000 tons each. Additionally, China produced about 370,000 tons of Chinese river crab (Eriocheir sinensis).