Living Fossils found in Singapore!

Have you guessed already by now the topic of this post? Yes, I'll be talking about horseshoe crabs, or "living fossils" as they are known because they have been around for the past 400 million years, before dinosaurs even existed!

Around the world, there are only 4 species of horseshoe crabs, out of which 2 can be found in Singapore! The species that can be found in Singapore are the Mangrove Horseshoe Crab (Carcinoscorpius rotundicauda) and the Coastal Horseshoe Crab (Tachypleus gigas) (Lee, 2014). As such, there is considerable interest in the conservation of horseshoe crabs in Singapore.

Personally, I have taken part in the Horseshoe Crab Rescue & Research Programme organised by the Nature Society (Singapore), in the Mandai mudflats. I have seen for myself how hardy these creatures are, having survived mass extinction with little morphological evolution. Sadly, irresponsible abandonment of fishing nets in the mudflats has resulted in the decline in horseshoe crab population. Due to their morphology, with their jointed appendages and long tail, horseshoe crabs get easily entangled in fishing nets. Unable to move and feed, they can only wait for death.

(Source: http://mygreenspace.nparks.gov.sg/living-fossils-horseshoe-crabs/)

During the rescue of horseshoe crabs, I saw the sheer numbers of them being caught in abandoned fishing nets. While some were still struggling for survival, many others were dead, having dried out when the tides receded. Regular volunteers of the programme shared about the interesting observation of how there would always be many more males than females caught in the nets. As they explained later on, once a female horseshoe crab gets caught in the nets, the pheromones released by the females would attract males towards them, leading to several more males getting caught in the nets as well. Unfortunate, isn't it, that a species that has survived millions of years could die out while responding to acts of nature, simply because of mankind's irresponsible behaviour?

References:
Lee, I. S. H., 2014. Living Fossils: Horseshoe Crabs. My Green Space. URL: http://mygreenspace.nparks.gov.sg/living-fossils-horseshoe-crabs/ (accessed on 28 Sep 2014)