Year of the Horse: Singapore’s equine-inspired neigh-tive species

SINGAPORE – There may not be any wild horses in Singapore but there are plenty of equine-inspired ones. In celebration of the Chinese Year of the Horse, The Straits Times highlights some of these native creatures.

Horseshoe crabs

Singapore has two species of these creatures, so named for their outer shell’s resemblance to shoes that protect horse hooves.

Mangrove horseshoe crab (Carcinoscorpius rotundicauda)

They grow up to 15cm in diameter, about the length of the iPhone 17. They tend to live in one mangrove throughout their lifetime. They are considered locally vulnerable.

Coastal horseshoe crab (Tachypleus gigas)

They can grow up to 25cm in diameter, bigger than their mangrove relatives. They inhabit spaces along the coast. They are considered locally vulnerable.

Horseshoe crabs are considered keystone species, which means that they help to hold the ecosystem together. Nutrients are released in their local environments when they forage.

Their eggs are also eaten by some bird species. Their blood can be used to detect toxins.

The survival of the horseshoe crabs is threatened by the loss of sandy beaches and mangrove habitats due to land reclamation and coastal development.

They can also die from entanglement in abandoned fishing gear.

Seahorses

There are three species here. Their equine links lie in their elongated heads, which resemble that of a horse, and their scientific names. In Latin, their genus Hippocampus means “horse” (hippos) and “sea monster” (kampos).

Estuarine seahorse (Hippocampus kuda)

These creatures are usually yellow or brown, and dwell mainly in areas with seagrass. They are considered critically endangered here.

Tiger tail seahorse (Hippocampus comes)

They inhabit coral reefs. They have yellow and black bands resembling tiger stripes, and are considered critically endangered here.

The last seahorse species assessed to be critically endangered in Singapore is the Japanese seahorse (Hippocampus mohnikei). It was first recorded in Changi in 1999. Due to the absence of past records in both India and Singapore, there is a possibility that the small fish was recently introduced.

The carnivorous creatures prey on living organisms, helping to maintain balance in the ecosystem by keeping their prey’s numbers in check. They are also a key indicator of the health of the habitat as they are sensitive to changes in the marine environment.

Although South-east Asia has a great diversity of seahorse species, they are not well studied, said Dr Adam Lim, director of non-profit Save Our Seahorses Malaysia.

For example, his team is currently in its 21st year of surveying Malaysia’s waters, while Singapore has minimal information on its seahorses. Work on seahorses and their relatives in Singapore is mostly sporadic and limited to sightings, he added.

Dr Lim is working with scientists and nature groups here to document the distribution and diversity of seahorses in Singapore’s waters.

Seahorses are threatened by habitat destruction and degradation.

They are poor swimmers that are extremely site-faithful. Displacement of seahorses from their natural habitat will disrupt their life cycle.

They also face indiscriminate destructive fishing, such as bottom trawling and fish bombings.

Horseshoe bats

These mammals are so named for their horseshoe-shaped noses. Singapore has four species.

Trefoil horseshoe bat (Rhinolophus trifoliatus)

These bats typically roost alone in vegetation under large leaves. They are considered endangered here.

Glossy horseshoe bat (Rhinolophus lepidus)

They roost in hollow trees, tunnels and drain culverts.

The other horseshoe bats native to Singapore are the greater woolly horseshoe bat and lesser brown horseshoe bat. Both are considered to be critically endangered here.

Horseshoe bats have voracious appetites. One bat can eat thousands of small flying insects in one night. This helps to keep insect numbers in check.

These creatures are nocturnal and live deep in the forest, which means they cannot be studied through simple observation, said mammal curator Marcus Chua. Researchers work at night using specialised equipment to detect and trap them.

In Singapore, they are primarily threatened by habitat loss and modification. The protection and reforestation of core forest habitats in Bukit Timah and Central Catchment Nature Reserves ensure their survival.

Horseflies

Unlike the other species which got their names from their appearance, this group of flies were named after their behaviour – females suck the blood of horses.

Horseflies are largely found in natural areas and tend to target local wildlife such as wild boars and monkeys. Recently, researchers caught a single specimen from a genus that appears to be new to science in Nee Soon Swamp Forest.

Horseflies co-evolved with large mammals so their presence usually signifies a healthy habitat with enough large fauna to support them, said entomologist Ang Yuchen. Changes in their diversity and abundance can show whether habitats are functioning well. The larvae of horseflies are freshwater predators of other invertebrates so they likely keep other pest species in check, he added.

“Being a nuisance to humans does not mean a species lacks ecological value,” said Dr Ang. “Many insects that people consider pests play important roles in ecosystems, and horseflies are no exception.”

Horseflies in Singapore are relatively understudied than more charismatic or economically significant species, added Dr Ang.

Even unpopular species can contribute to the balance of the ecosystem, such as flies of the genus Forcipomyia. Its females feed on blood and help pollinate cocoa flowers.

He noted that there is not much push to research horseflies because they are not too important or numerous yet.

SOURCES: NATIONAL PARKS BOARD, LAURA YAP, ADAM LIM, MARCUS CHUA, BAT CONSERVATION INTERNATIONAL, COLLINS DICTIONARY, ANG YUCHEN