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Phylum Arthropoda > Subphylum Crustacea > Class Malacostraca > Order Decapoda > prawns and shrimps
Snapping shrimps
Family Alpheidae
updated Feb 13
if you learn only 3 things about them ...
You will probably hear one than see one on the shores. Listen out for them!
The enlarged pincer can be as big as the rest of the shrimp!
Sometimes, a goby share the burrow with the shrimp.

Where seen? You will most likely hear a snapping shrimp before you see one. These little creatures make the incessant pops that you hear at low tide. They range from tiny ones to rather large ones that can pack a really loud pop. They are common on many of our shores, on mudflats, sandy shores, in seagrass meadows, rocky areas and reefs. But they are often tucked away in their burrows or other hiding places such as under rocks, even under carpet anemones and within sponges. Snapping shrimps forage outside their burrows more actively at night.

What are snapping shrimps? Snapping shrimps are crustaceans that belong to Family Alpheidae.

Features: 2-7cm long. A snapping shrimp has one of its pincers greatly enlarged. This pincer may even be as long as its entire body!
The enlarged pincer can produce a very loud sound. The blast stuns prey like tiny fish and cracks the shells of small clams. It is also used to warn off predators and intimidate rival snapping shrimps. It crawls slowly on the sea bottom with long walking legs. It can make a quick getaway by contracting its muscular flexible abdomen and broad fan-shaped tail. The shrimp has small eyes, which is probably why some live together with gobies that have much better eyesight (see below).

The science of The Sound: A study of one species of snapping shrimp shows the pincer has a moveable 'finger' held at right angles to a matching 'socket' on the opposite side.
When the 'finger' is released, it plunges rapidly into the socket, and an explosive sound results. The snapping sound is not the result of the finger hitting the socket, i.e., not like the sound of hands clapping. Rather, a high-speed jet of water shoots out of the socket due to extremely rapid compression as the 'finger' plunges into the socket. This jet vapourises the water and creates large bubbles. The bubbles rapidly collapse (called cavitation), releasing an extremely loud sound as well as a flash of light, and for a brief moment, at high temperatures. These findings are possibly useful for naval applications as the sound of snapping shrimps seriously interfere with sonar detection in shallow seas. In fact, snapping shrimps have been studied since World War II as their sounds interfered with the detection of hostile submarines!

Shrimpy friends: Some species live in symbiosis with corals, sponges, sea fans and other animals. The most amazing must be the relationship between the snapping shrimp and goby. The shrimp goby lives in the same burrow with a snapping shrimp. With keener eyesight, the goby keeps a look-out while the shrimp busily digs out and maintains their shared home. The shrimp is literally constantly in touch with the goby with at least one of its antennae always on the goby. When the goby darts into the burrow, the shrimp is right behind it!

Colonial shrimps? A kind of snapping shrimp (Synalpheaus regalis) that lives in sponges in the coral reefs of Belize were found to form colonies much like termites do. One 'queen' prawn produces all the members of the colony, which attack members of other colonies but are peaceful towards members of their own colony.

Status and threats: Most of our snapping shrimps are not listed among the endangered animals of Singapore, except for the Crinoid snapping shrimp (Synalpheus stimpsoni). This tiny shrimp (about 1cm) lives in pairs on feather stars (crinoids), feeding off the mucus of its host. It is threatened by reef destruction and siltation.

One pincer greatly enlarged.
Pulau Sekudu, Jun 05



Using the small pincer to carry things.
Labrador, May 02


Sideview of the shrimp
St. John's Island, May 06



This shrimp shares its burrow with a brittle star.
Chek Jawa, Jul 05

Snapping shrimps on Singapore shores



Commensal snapping shrimp
in sponges and under stones

White soft coral snapping shrimp
in ball flowery soft corals
 

Family Alpheidae 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 our observation
**from WORMS

  Snapping 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.
  Commensal snapping shrimps
White soft coral snapping shrimps
Many-band snapping shrimps
Ornamented snapping shrimps
Smooth snapping shrimps

  Family Alpheidae
  Alpheus angustidigitus
Alpheus audouini=**Alpheus edwardsii
Alpheus bengalensis
+Alpheus brevicristatus

Alpheus carnicauda
Alpheus chiragricus
Alpheus crassimanus=**Alpheus lobidens
Alpheus euphrosyne
Alpheus idae
Alpheus lanchestri
+Alpheus lobidens

Alpheus lutini=**Alpheus obesomanus
Alpheus microrhynchus
(EN: Endangered)
Alpheus paralcyone
Alpheus rapacida
Alpheus rapax
Alpheus semmelinki
Alpheus spongiarum
Alpheus stanleyi
Alpheus trompi
Alpheus ventrosus=**Alpheus lottini


*Athanas japonicus (VU:Vulnerable)
Athanas jedanensis
Athanas monoceros
Athanas parvus
*Athanas polymorphus
(VU: Vulnerable)

*Potamalpheops amnicus (EN: Endangered)
*Potamalpheops johnsoni (VU: Vulnerable)
*Potamalpheops tigger (VU: Vulnerable)

*Salmoneus singaporensis (CR: Critically endangered)


Synalpheus acanthitelsonis=**Synalpheus hastilicrassus
Synalpheus bituberculatus
Synalpheus comatularum
Synalpheus gravieri
Synalpheus neomeris=**Synalpheus neomeris
Synalpheus neptunus
Synalpheus pescadorensis
Synalpheus quadrispinosus
Synalpheus stimpsonii
(Crinoid snapping shrimp) (CR: Critically endangered)
Synalpheus stormi
Synalpheus tumidomanus

Links
References
  • Michel Versluis,et al (2000). How Snapping Shrimp Snap: Through Cavitating bubbles, Science, 289, 2114. DOI: 10.1126/science.289.5487.2114 with a layman's explanation Snapping Shrimp by Kristin Leutwyler on Scientific American.
  • D. Lohse, B. Schmitz & M. Versluis (2001). "Snapping shrimp make flashing bubbles". Nature 413 (6855): 477-478. DOI:10.1038/35097152.
  • Chou, L. M., 1998. A Guide to the Coral Reef Life of Singapore. Singapore Science Centre. 128 pages.
  • 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.
  • Lim, S., P. Ng, L. Tan, & W. Y. Chin, 1994. Rhythm of the Sea: The Life and Times of Labrador Beach. Division of Biology, School of Science, Nanyang Technological University & Department of Zoology, the National University of Singapore. 160 pp.
  • Jones Diana S. and Gary J. Morgan, 2002. A Field Guide to Crustaceans of Australian Waters. Reed New Holland. 224 pp
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