Desis martensi, commonly known as the reef spider or marine spider, is a true marine spider that can be found along the intertidal zones of Singapore. It was first described by Dr. Ludwig Carl Christian Koch in 1872.
Figure 1: Desis martensi specimen observed on St John's Island in Singapore.
Photo credit: Kieron Gabriel Ng.
IUCN Red List: NE (Not Evaluated)
Singapore Red Data Book 2008: Vulnerable
Genus: Desis (Walckenaer, 1837)
(L. Koch, 1872)
The species is named after German marine zoologist Dr Eduard von Martens, who discovered and collected the species in Singapore in 1861 on coral reefs fringing the area that is now known as Sentosa. It was then described by German entomologist and arachnologist Dr. Ludwig Carl Christian Koch in 1872.
Desis martensi can be found in the inter-tidal zone, in habitats such as rocky shores or coral reefs, making their nests in groups inside hollow corals or rocks. During low tide, they are often found scurrying around the surface of corals or rocks, or scuttling across the water surface. They retreat back into their nests during high tide.
Like all spiders, Desis martensi also possesses spinnerets and is able to spin webs. However, rather than for prey capture, Desis martensi utilize their webs to line the inside and outside of their nests in corals or rocks.
Furthermore, although Desis martensi is found in the intertidal habitat, and is a true marine spider, it does not have the ability to respire through seawater like most other aquatic arthropods do. Thus it relies on creating air pockets in its nests with webbing in order to survive high tide.
- old paper
Figure 4: Video of active Desis martensi specimens observed on St John's Island in Singapore.
Video credit: Kieron Gabriel Ng.
Desis martensi is native to Singapore. However, it has been found recently along some coastlines in indonesian archipelago.
Google maps of sightings
Desis martensi has not yet been evaluated by the IUCN red list.
However, it is listed as 'Vulnerable' in the Singapore Red Data Book 2008
Desis martensi have been observed to consume small marine invertebrates the are abundant across the intertidal zone, such as sea slaters or shrimp. It has also been observed venturing onto the shore to hunt prey such as crickets.
Desis martensi spin waterproof silk cocoons and seal their eggs inside them.