Box jellyfish the size of 10-cent coins spotted in S'pore mangroves, harmless to humans


Sumita Thiagarajan | December 26, 2020, 03:00 PM

Singapore is home to a large variety of wildlife, both on land and in water.

Some marine animals might be easier to spot (due to their size), such as dolphins and sea turtles.

The mangrove box jellyfish, however, might require keener eyes.

Jellyfish as small as your thumb's fingernail

While some species of box jellyfish are larger in size (and venomous), this particular species is so tiny that one could mistake them for baby jellyfish.

According to a Facebook post by Kayakasia, their staff encountered jellyfish that were the size of 10-cent coins in a mangrove river in Singapore.

Here's a description of how they moved:

"Then the unmistakable darting movement of jellyfish caught my squinting eyes. I was surprised how small they were and how fast they moved."

The almost transparent creatures were picked up by the team at Kayakasia using a discarded coke bottle for the Lee Kong Chian Natural History Museum (LKCNHM), who identified the species as mangrove box jellyfish (Tripedalia cystophora).

A jellyfish researcher at LKCNHM said that the collected jellyfish will be photographed, have tissue taken for molecular work and preserved, according to Kayakasia.

Here's a close look at the adorable little jellyfish:

Photo by Iffah Iesa

Photo by Iffah Iesa

Not known to inflict significant venom on humans

The tiny jellyfish feed on small prey that are related to the family of shrimps, and prawns.

According to Singapore Biodiversity Records, the mangrove box jellyfish is not known to inflict significant venom on humans.

In a previous record of this species, the mangrove jellyfish has been spotted in Pulau Ubin in 2004.

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Top images by Iffah Iesa