17th October 2020, Saturday
It appears that heart urchins are hot on our heels this year! ๐ Thanks to a volunteer’s keen-eyed observation, we reported yet another new species record for Singapore waters.
During a leisure dive by avid marine volunteer, Ms Toh Chay Hoon, she had found a single denuded heart urchin test with a test length of around 7 cm on the subtidal silty bottom (see accompanying picture). Given our recent interests on them, Chay Hoon and other volunteers alerted us (Teresa and I) to this heart urchin.
Although the specimen is dead, it is much easier to identify heart urchins based on their denuded tests as the morphological traits will become more distinct. Here, the petaloids (that looks like arms) on the aboral side is highly unique compared to those previously observed (see Neo et al., 2020; Tan et al., 2020). We have here a specimen of Brissopsis luzonica – which was kindly identified by Dr Camille Souto. Dr Souto is a marine palaeontologist who studies living and fossil ocean animals, especially echinoderms like sea urchins. She clued us in to look at this species, and we managed to match up the diagnostic features to the descriptions. ๐
This new species record adds on to the growing list of heart urchin species known to occur in Singapore waters, which already includes four other species: Lovenia elongata, Maretia planulata, Metalia spatagus and Brissus latecarinatus (Lane & Van den Spiegel, 2003; Neo et al., 2020; Tan et al., 2020).
Until the next discovery!
References:
- Lane DJW, LM Marsh, D Van den Spiegel & FWE Rowe (2000) Echinoderm fauna of the South China Sea: an inventory and analysis of distribution patterns. Raffles Bulletin of Zoology 8: 459โ493.
- Lane DJW & Van den Spiegel D (2003) A Guide to Sea Stars and Other Echinoderms of Singapore. Singapore Science Centre. 187 pp.
- Neo ML, TS Tay, JHS Ng & S Lee (2020) New record of heart urchin, Metalia spatagus, in Singapore. Singapore Biodiversity Records 2020: 16.
- Schultz H (2017) Echinoidea. Volume 2: Echinoidea with bilateral symmetry. Irregularia. In: Schmidt-Rhaesa A (ed.), Handbook of Zoology. De Gruyter. Pp. 159โ161.
- Tan R, TS Tay & ML Neo (2020) New records of the keeled heart urchin, Brissus latecarinatus, in Singapore. Singapore Biodiversity Records 2020: 26-27.
- Toh CH, TS Tay & ML Neo (2020) New record of heart urchin, Brissopsis luzonica, in Singapore. Singapore Biodiversity Records 2020: 206.
Mei Lin Neo 