LONDON, Nov. 8 (Xinhua) -- London's newest inhabitants have been discovered living in the capital's famous River Thames, marine biologists revealed Wednesday.
The scientists from London Zoo's international conservation charity ZSL reported new evidence of seahorses living in London's iconic waterway.
They said the sighting of a sixth individual animal in the past two months alone, compared with previous averages of just one or two annual sightings, underlines the importance of the Thames and its estuary as a haven for wildlife.
The most recent sighting of a short-snouted seahorse (Hippocampus hippocampus) was recorded by an ecological survey team working at Greenwich.
It is not yet known what might have caused the surge in sightings, said ZSL.
Anna Cucknell, ZSL's Estuaries and Wetlands Conservation Manager for said: "We're really excited to be finding more and more evidence suggesting seahorses are resident in the Thames. The limited research work to date suggests that two species in particular now call London's estuary home: the short-snouted seahorse and the spiny seahorse (Hippocampus guttulatus).
"Both tend to prefer shallow coastal waters and estuaries, so we shouldn't be too shocked to find them here. But the fact that both species typically have small home ranges and don't tend to travel far gives reason to believe that the seahorses we've found recently are permanent residents rather than occasional visitors."
The seahorse sightings are the latest indicator of how biodiverse and important the Thames is for a number of species: from tiny invertebrates like shrimp and insect larvae; to over 125 species of fish, including the critically endangered European eel.
"There are also inhabitants, including harbor seals and grey seals, highlighting how little we know about many of the species inhabiting the estuary running through the nation's capital," added ZSL.
ZSL is co-founder of an initiative, Project Seahorse, set up to learn more about the species.
Project Seahorse co-founder and ZSL Head of Marine and Freshwater Conservation Programs, Dr Heather Koldewey, said: "Our involvement as co-founder of Project Seahorse makes ZSL a global hub of expertise on these charismatic species, so it's really exciting to see them increasingly being found right on our doorstep in London."
The project is collaboration between ZSL and the University of British Columbia.