Shrimps are decapod crustaceans with prolonged bodies and swimming styles of movement.
This is common mostly in Dendrobranchiata and Caridea.
Under a wider definition, shrimp are sometimes regarded as prawn, covering stalk-eyed swimming crustaceans with long, narrow muscular tails (abdomens), long antennae, and thin legs.
They swim forward by paddling with swimmers at the bottom of their abdomen, although their escape response is usually repetitive, with the tail propelling them backward very quickly.
In the food chain, shrimps Play a very significant part, and they are a good source of food for humans and other larger animals ranging from fish to whales.
Many shrimp’s muscular tails are human-edible and often caught and bred for human consumption.
Commercial shrimp species sustain an industry worth $50 billion annually, and as of 2010, the total commercial shrimp production was nearly 7 million tons.
The species of shrimps vary in size, ranging from 0.79 inches to 9.8 inches.
Classification
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Malacostraca
- Subclass: Eumalacostraca
- Superorder: Eucarida
- Order: Decapoda
- Suborder: Natantia
- Superfamily: Penaeoidea
- Family: Penaeidae
- Genus: Penaeus
- Scientific name: Caridea
Description
A shrimp’s body has two divisions: the head and thorax(chest), fused to form Cephalothorax and a long abdomen.
The Cephalothorax is protected by a shell that is thicker and harder than any other shell covering other parts of the shrimp. It is through the carapace, which encircles the gills, that water is pumped by the movements of the mouthparts.
The whiskers, rostrum, legs, and eyes also emanate from the carapace. The rostrum, which is beak-like in shape, is situated at the front of the shrimp’s head and can serve as a shield or a weapon for attacking the shrimp.
There are six segments in the muscular abdomen, and the shell found there is thinner than the carapace. Each of the six segments has a separate shell that overlaps each other.
Each of the first five segments has a pair of paddle-like appendages on the underside, used for swimming in the forward direction. The appendages are otherwise called swimmerets or pleopods.
The sixth segment ends in the telson with a double pair of appendages called Uropods on both wings.
Habitat
Shrimps are very common; they are mostly found near the seafloor of most estuaries, lakes, seas, coasts, and rivers.
The species of shrimps are vast, and each species adapts to a particular habitat. At a depth measuring 16,000ft, marine species are found, and they come from the tropics of the polar regions.
Of the numerous species of aquatic shrimps, only the two species of Merguia are semi-terrestrial, and they live mostly on land in mangroves.
Lysmata amboinensis, a shrimp species, lives in partially shallow waters and rests at the bottom of the sea using their walking legs.
Behavior
Different species of shrimps behave and look differently. Let us take, for example, the core group of Caridea shrimp. In this group, Peterson’s subtle and delicate shrimp behaves differently from the large commercial pink shrimp.
What characterizes the Caridea family of shrimps is their claws, which are asymmetrical in arrangement.
It is worth noting that the primary source of noise in the ocean is the snapping shrimp that appear in colonies. Because of this noise created by the colonies, they tend to obstruct underwater and sonar communication.
Shrimps are mostly omnivores, though some have a special mode of feeding. Some shrimps are considered filter feeders and use their bristly or setose as a sieve.
Other species of shrimps, like the cleaner shrimp, feed on the necrotic tissue of reef fish and parasites of the reef fish. Some species of shrimp also feed on other smaller shrimps, especially when their food source is unavailable.
Mating
The female shrimps belonging to the Caridina ensifera species store sperm from several male shrimps. As such, they can produce offspring with different paternities.
Species
1. Decapods
Decapods are traditionally divided into two subgroups: Reptantia, or walkers, and Natantia, or swimmers. Shrimps fall under Natantia, while crabs and lobsters belong to the Reptantia or walkers.
It was a common belief that all shrimps were Decapods or paraphyletic.
2. Non-decapods
Most shrimps are widely referred to as non-decapod crustaceans. Included also in this species are various shrimps like fairy shrimp, brine shrimp, tadpole shrimp, and clam shrimp, which belong to the Branchiopods, and opossum shrimp lophogastridan shrimp, and skeleton shrimp, which belong to Malacostraca.
Most of these shrimps differ greatly from the commercial decapod shrimp consumed as seafood.
Human Uses
Most shrimps are widely used commercially, sold at the market, and eaten as seafood. They are a great source of protein and cholesterol. At home, shrimp are used as ornaments and in aquaria to add beauty to the home.
