The sea off the Port of Spain Waterfront was dotted this week with a bloom of cannonball jellyfish (Stomolophus meleagris) that swarmed the coastline, lazily ebbing and flowing with the tide.
The odd little mushroom-shaped creatures fascinated water-taxi commuters and pedestrians who chanced to look out into an ocean usually devoid of observable life.
"Pulses of cannonballs are popular ever so often during the northern winter/springtime period," said Jahson Alemu, a coral reef ecologist at the Institute of Marine Affairs.
The creatures, he said, were not strange to our waters, but were usually found around Chaguaramas and the islands around the Dragon's Mouth.
"They go wherever the tide takes them—in this case, the Waterfront," he said.
Despite the huge numbers, it is still safe to go into the water—the cannonball jellyfish is not dangerous to humans.
Local sea bathers may be familiar with the colourful blob of the lethal Portuguese man-o'-war which frequent local waters, particularly during the Easter season, whose stringy tentacles can deliver a powerful sting.
But Alemu said cannonballs were quite docile, and swimmers could easily push them away if they venture too close; but the high density would obviously mean a higher chance of contact.
There is also a chance of the jellyfish getting caught in boat engines, so he advised small craft operators especially to be aware.
"It's better to be safe than sorry, so exercise caution," he said.
The cannonball's toxin is not very harmful to humans, but people with sensitivity should take extreme precautions to avoid contact.
The cannonball feeds primarily on zooplankton, but they are the main food source for the leatherback sea turtle. As the turtles migrate north from the Caribbean (after nesting), they feed on the jellyfish.
Trinidad is one of the most significant Atlantic nesting sites for the endangered animal, with the nesting season starting in March and lasting for about six months.