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Electric rays
Family Narcinidae
updated
Sep 2020
Where
seen? This rather chubby ray with a stumpy tail was seen
on Changi several times, among seagrasses. Elsewhere, they are found
in sandy, muddy areas, from river mouths to coral reefs. It was previously in Family Torpenididae.
What are electric rays? Electric rays
are rays belonging to Order
Torpediniformes. Some scientists group these fishes in the Family Narcinidae
which according to FishBase has 9 genera and 24 species. They are found in the Atlantic, Indian
and Pacific Oceans. Numbfishes are different from stingrays that belong to the Family Dasyatidae.
Features: 15-60cm in diameter.
Body flattened disc-shaped. Like other rays, it takes water in from
gill openings on the upperside of the body, expelling water out from
gill slits on the underside, enlarged pectoral fins along the body
edges. Unlike stingrays, the numbfish has a pair of obvious dorsal
and a tail fin too. The tail is short and fat and not whip-lik, and
lacks stinging barbs..
The Dark-spotted numbfish (Narcine maculata) has a round body about 10cm in diameter. Beige with large maroon spots of varying sizes.
Short fat tail with two round (circular) dorsal fins and a round tail fin. |
Gill openings behind the eyes. |
Narcine maculata
Short fat
tail with round dorsal and tail fins.
Changi, Jun
05 |
Shocking! Electric rays have a pair of kidney-shaped electric organs
at the base of the pectoral fins that can produce mild to strong electric
shocks. Thus their common name. Their scientific name comes from the
Greek 'narke' which means 'paralysis'. So don't touch them. Watch your step. Do not step into murky water. Do not put your hand into holes and crevices. |
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What do they eat? Electric rays
use their electric power to stun fishes that they eat. While most
eat small fishes, some species can stun relatively large fishes that
are eaten whole. The jaws and mouth are highly protrusible forming
a tube to suck up prey. Some shallow water species spend most of their
time buried in the sand with only their nostrils visible.
Electric babies: These fishes give birth to live young,
producing small litters. |
Electric rays
on Singapore shores |
Other sightings on Singapore shores |
Narcine maculata
Chek Jawa, Jul 04
Photo shared by Lim Cheng Puay. |
Narcine maculata
Changi, Jun 12
Photo shared by Marcus Ng on flickr. |
Links
References
- Chan Sow Yan. 17 Jan 2014. Dark-spotted
numbfish (Narcine maculata) neonate at Changi Beach.
Singapore Biodiversity Records 2014: 22
- Allen, Gerry,
2000. Marine
Fishes of South-East Asia: A Field Guide for Anglers and Divers.
Periplus Editions. 292 pp.
- Kuiter, Rudie
H. 2002. Guide
to Sea Fishes of Australia: A Comprehensive Reference for Divers
& Fishermen
New Holland Publishers. 434pp.
- Lieske,
Ewald and Robert Myers. 2001. Coral
Reef Fishes of the World
Periplus Editions. 400pp.
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