|
|
|
Amphipods
Order Amphipoda
updated
Mar 2020
Where
seen? The most commonly encountered are tiny ones in large
numbers among seaweeds, especially when there is a bloom of Hairy
green seaweed (Bryopsis sp.).
What are amphipods? They are crustaceans that resemble shrimps. While shrimps belong to the Class Decapoda,
beachfleas and other amphipods belong to the Order Amphipoda. Among
the most numerous and most diverse of bottom-dwelling crustaceans,
they are sometimes also called amphipods, sand hoppers or sandfleas.
While most beachfleas are tiny, one monstrous beachflea (Alicella
gigantea) grows to 25cm! Fortunately, we are unlikely to encounter
it as it lives at the bottom of the deep sea.
Features: 0.5cm or less. Their bodies are flattened sideways
(instead of downwards as in isopods). Their eyes are NOT on stalks. They have seven pairs
of limbs, the first two pairs may have claws and are used for feeding
and in mating. The remainder are walking legs. Amphipoda means 'different
feet' while Isopoda meaning 'same feet'. Many can hop long distances
by flexing their long abdomens. |
Kusu Island, May 05 |
|
|
Skeleton shrimps are tiny amphipods that belong to Family Caprellidae.
They have a long skinny translucent body with many limbs. The last
3 pairs of limbs grip stuff while the body extends outwards. Near
the head, a pair of humungous pincers are used to snatch tiny tidbits
and prey. They also have other pairs of limbs near the front used
to grab on to stuff, so they can move like an inch-worm.
What do they eat? Most beachfleas
are scavengers or feed on detritus. Some are filter feeders. A few
are predatory while some are parasites on larger animals.
Beachflea babies: Beachfleas mums
brood their young in special pouches under their chest.
Role in the habitat: Beachfleas
are eaten by many animals and are an important part of the food chain. |
Sisters, May 12 |
Sisters, May 12 |
Amphipods
on Singapore shores |
Other sightings on Singapore shores |
Sentosa, Nov 09 |
Sentosa, Nov 09 |
|
Sisters Island, May 12
Photo shared by James Koh on his
blog. |
Sisters, May 12 |
Links
References
- Edward E.
Ruppert, Richard S. Fox, Robert D. Barnes. 2004.Invertebrate
Zoology
Brooks/Cole of Thomson Learning Inc., 7th Edition. pp. 963.
- 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.
|
|
|