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Phylum Arthropoda > Subphylum Crustacea > Class Malacostraca > Order Decapoda
Prawns and shrimps
updated Oct 13
if you learn only 3 things about them ...
There is no scientific difference between shrimps and prawns.
Many are well camouflaged, others are buried in the sand, yet others transparent.
Some live on other animals such as sea anemones and hard corals.

Where seen? Among our favourite seafood, prawns and shrimps come in various sizes and colours. Close observation is needed to appreciate their delicate patterns and colours, and amusing behaviour. Prawns and shrimps are common on almost every shore. However, they are difficult to spot as they are often small, and hide in burrows or just beneath the sand. Even those in plain sight disappear from view as many are nearly transparent. They are adapted for bottom dwelling.

What are prawns and shrimps?
Prawns and shrimps are crustaceans that belong to various groups in the larger Order Decapoda. There are no clear scientific differences between prawns and shrimps. Generally, smaller ones are called shrimps while larger ones prawns.

Features: Usually less than 5cm long. Unlike crabs which have stiff shells to protect their abdomen, a shrimp has a thin, flexible shell over a long abdomen that ends in a broad fan-like tail. A quick contraction of the muscular abdomens propels the shrimp backwards. To swim slowly, the shrimp paddles with the small swimmeretes (pleopods) under the abdomen.

Many shrimps are transparent, blending in wherever they are. Some may be red, a colour that is hard to distinguish in the dark or in deeper water.

What do they eat? Larger shrimps are mostly scavengers or eat small plants and animals. Smaller ones feed on plankton and algae.

How do they mate? Shrimps have separate genders. To mate, a male inserts his sperm packet into a special receptacle in the female. Fertilisation, however, is external. The female releases the sperms from the packet together with her eggs. A female prawn produces a huge number of eggs, as much as one million in one spawning! Some may carry their eggs under their tails.

Prawn babies: Like many marine creatures, shrimps undergo metamorphosis. That is, they change their shape as they develop through their life cycle. Most adult shrimps migrate to deeper waters to breed and release their eggs. Eggs usually hatch quickly, within a day or so.

After hatching from the egg, the larvae look nothing like the adults! These larvae drift with the plankton, changing shape as they develop further. Eventually, they look more shrimp-like and migrate back to shallow waters. Here they develop into mature adults before starting the cycle all over again.

larvae


juvenile


adult

Role in the habitat: Shrimps are numerous and eaten by a wide variety of larger creatures. In coral reefs, some species of shrimps act as cleaners, picking parasites and dead skin off fishes. The fish 'clients' allow the cleaner shrimps to do their job without eating them. These cleaners are often brightly marked. Some shrimps also live with other sea creatures. Anemone shrimps, for example, frolick happily among the tentacles of a sea anemone that would kill and eat other creatures.

Human uses: Shrimps and prawns are relished by people everywhere. In Asia, shrimps are eaten in many ways. Besides the usual dishes made from whole shrimps, they may also be dried, or made into paste ('belachan') or mixtures ('cincaluk'). Tiny shrimps are used as condiments, and shrimps flavour crackers, balls and other delicacies. While traditional farming and harvesting methods are sustainable, large-scale commercial prawn farms and prawn trawling are more destructive and unsustainable. More about prawn farming and trawling.

Status and threats: Some of our shrimps and prawns are listed among the threatened animals of Singapore. However, like other creatures of the intertidal zone, they are all affected by human activities such as reclamation and pollution. Trampling by careless visitors and over-collection can also have an impact on local populations.


The Penaeid prawn is a seafood favourite!


The Blue-tail prawn like other shrimps
contracts its abdomen to swim backwards.



A pair of Five-spot anemone shrimps is commonly
found in our carpet anemones.



Red-nose shrimps are also found among
seaweeds, and living hard and soft corals.



Snapping shrimps are often heard
before they are seen!

Marine shrimps and prawns recorded for Singapore
from Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
in red are those listed among the threatened animals of Singapore from Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore.
*from Tan, Leo W. H. & Ng, Peter K. L., 1988, A Guide to Seashore Life
**from Lim, S., P. Ng, L. Tan, & W. Y. Chin, 1994. Rhythm of the Sea: The Life and Times of Labrador Beach.
+from our observation.
^from WORMS

  Prawns and shrimps seen awaiting identification
Species are difficult to positively identify without close examination of small features. On this website, they are grouped by external features for convenience of display.
  Red-banded shrimps
Humpbacked shrimps

  Family Penaeidae (penaeid prawns) with list of species recorded for Singapore

Infraorder Caridea
  Family Alpheidae (snapping shrimps) with list of species recorded for Singapore

  Family Atyidae (freshwater shrimps)
Most members of this family are freshwater shrimps
  Caridina gracilirostris
Caridina peninsularis
Caridina propinqua
(Mangrove hairy-handed prawn)
Caridina tonkinensis
Caridina weberi sumtrensis
Caridina temasek
(Temasek shrimp) (EN: Endangered)

  Family Hippolytidae (humpbacked shrimps and cleaner shrimps)
  Gelastocaris paronae

Hippolysmata enriostris=^Exhippolysmata ensirostris ensirostris
Hippolysmata vittata=^Lysmata vittata

Hippolyte ventricosa

Latreutes mucronatus
Latreutes pymaeus=^Latreutes pymoeus

Lysmata sp. (Cleaner shrimp)
**Lysmata vittata

Mimocaris heterocarpoides

Saron sp. (Saron shrimp)
Saron marmoratus
(Marbled shrimp)
Saron neglectus

Thor paschalis

  Family Palaemonidae (glass shrimps and commensal shrimps)
with list of species recorded for Singapore

  Family Pandalidae (marine carid shrimps)
  Chorotocella gracilis

Heterocarpoides levicarina=^Procletes levicarina

 
  *Family Sergestidae
  *Acetes sp. (Belachan shrimp)
Acetes japonicus

  Family Thalassocarididae
  Chlorotocoides spinicauda


Infraorder Stenopodidea

  Family Stenopodidae (boxer shrimps)
  Stenopus hispidus

Links References
  • Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore. National Council on the Environment. 163pp.
  • Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore Red Data Book: Threatened plants and animals of Singapore. Nature Society (Singapore). 285 pp.
  • Ong, Jin Eong & Gong, Wooi Khoon (eds.), 2001. The Encyclopedia of Malaysia (Vol. 6): The Seas Didier Millet, Malaysia. 144 pp.
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