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Home › Ocean Life › Marine › Invertebrates › Crustaceans › Shrimps

Interesting Facts about Sea Shrimps

[Shrimp Phylum: Arthropoda] [Class: Malacostraca] [Superorder: Eucarida] [Order: Decapoda]

There are around two thousand (2,000) different species of shrimp living in various marine environments. Even so, about five hundred of them are semi-terrestrial shrimps found in fresh water.

This section contains fun facts about shrimp crustaceans, including where they thrive best, what they eat, and how they reproduce.

Where Do Shrimp Species Live in the Ocean

Some shrimps are pelagic (living in the water column) and others exist near hydrothermal vents - thousands of metres deep. But, the frequent places to find sea shrimp species include:

• Colorful coral reefs, coral heads, and sea anemones (e.g. the cleaner shrimps).
• Mangroves and seagrass beds that create sheltered nursery grounds for juvenile shrimp.
• Shallow seas, estuaries, and coastal bays, often close to sand or mud bottoms.

So, because a shrimp is an invertebrate, let's look at what kind of habitats they need. The burrowing and foraging shrimps prefer a location with a soft bottom (ideally mud, sand, or silt).

Whereas, many reef shrimp species live around hard coral structures or rocky outcrops. Either way, these burrows, crevices, and corals provide them with some shelter against a multitude of natural predators.

Interesting Fact: The semi-terrestrial shrimp (Merguia rhizophorae) is one of the shrimp animals commonly seen in mangrove ecosystems and noted for its ability to live out of water for long periods of time.

Sea Shrimp Characteristics

There are several important physical features and characteristics that many underwater shrimp have in common.

For example, most of the ocean shrimp species have a hard exoskeleton (a shell made of chitin).

The main body segments are divided into the head and thorax (cephalothorax) and the muscular tail (called the abdomen).

Shrimp crustaceans also have antennae (to help them sense vibrations) and compound eyes located on stalks.

The walking legs (pereiopods) are capable of grasping objects, and the swimming legs (known as pleopods or swimmerets) located on the underside of the abdomen can also be used to carry eggs.

Sea shrimps use their flattened tail fan for swimming backwards, such as when trying to avoid capture from their predators.

They have a range of traits and behavioural characteristics. Some genus of shrimp are burrowers that dig into soft substrates for protection. Whereas, other shrimp classifications set up "fish cleaning stations" to remove parasites from their "clients".

Sea Shrimp Size

Some of the biggest shrimps (often called prawns) can grow up to twenty (20) centimetres in length (8 inches).

Stygotantulus stocki is one the smallest sea shrimp species which measures only 0.1 millimetres. In comparison, the giant tiger prawn (Penaeus monodon) is one of the biggest used as commercially consumed shrimp, and fully grown adults can measure 33 centimetres long (13 inches).

Pro Tip: Another section contains more information about sea shrimp anatomy and how the different body parts work.

What Do Saltwater Shrimps Eat?

Even though most ocean shrimps are omnivores that consume algae, plankton, and decaying detritus material, some of the cleaning shrimps (e.g. Lysmata amboinensis) are swimming decapod crustaceans that also feed on ectoparasites, dead tissue, and mucus from any "willing" participants - an activity known as "cleaning symbiosis".

Types of Shrimp in the Ocean

How Do Shrimps Reproduce?

The reproductive strategies of sea shrimp crustaceans vary between different species. Even though most shrimps have separate male and female sexes, many of the cleaner shrimps (Lysmata) are simultaneous hermaphrodites that produce eggs and sperm.

In general, mating occurs soon after a female molts her exoskeleton. So, while it's soft, external fertilisation takes place when a male deposits packets of sperm (called spermatophores) near the female's reproductive opening.

But wait - there's more:

Fertilised eggs attach themselves to the pleopods (swimming legs) located on the underside of the female's belly (abdomen). Then, she fans her pleopods to aerate the eggs and to help keep them clean.

Once they hatch, shrimp eggs become a type of planktonic larvae that pass through several important stages and change shape as they start to grow and develop from juveniles to adults as they find a suitable location to settle on the seabed.

Interesting Fact: Because cold water temperatures tend to slow shrimp development, some deep-sea shrimps that live near hydrothermal vents, such as the blind shrimp (Rimicaris exoculata), need to carry the eggs for much longer than the coastal species.

Threats and Predators

Even though saltwater shrimps are small, they are extremely nutritious and a vital food source for many marine species, especially vertebrate fishes and octopuses.

Other contributing factors for the decline in a few vulnerable areas include certain types of human behaviour (e.g. coral reef destruction and degradation, overfishing).

Important: The IUCN Red List of Threatened Species is a comprehensive source of information about the global conservation status of animals, fungi, and plants. Currently, the IUCN lists the vast majority of sea shrimp species as being of "Least Concern" (LC).

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