New evidence of climate warming? Tropical species "Cryptoplax larvaeformis" discovered in Little Liuqiu

Reported by You Tzu-ju / Compiled by staff

The species "Cryptoplax larvaeformis," widely distributed in tropical waters near the equator of the Pacific Ocean, has appeared in the intertidal zone of Little Liuqiu, marking the first confirmed record in Taiwan’s subtropical waters. This northward spread of a tropical species provides further evidence of global climate warming.


▲Cryptoplax larvaeformis – Photo by Dr. Chen Wenrou. (Image provided by Kaohsiung Wild Bird Society)

The species was recorded during a routine intertidal monitoring survey conducted recently by a research team led by Associate Professor Lo Liou-chih from the Department of Geography at National Kaohsiung Normal University in the intertidal zone of Little Liuqiu.
It belongs to the class Polyplacophora, family Cryptoplacidae, within the phylum Mollusca. Common chitons found in the intertidal zone usually have eight large shell plates covering their backs, providing tight protection for their bodies. In contrast, Cryptoplax larvaeformis has reduced shell plates scattered across its back, offering little protection, which is why it typically lives in crevices of coral reefs that are not exposed to strong wave action, feeding on algae.

Juveniles retain intact shell plates until adulthood. The body is elongated and worm-like, reaching up to 15 cm in length, with both ends being bluntly rounded. The dorsal shell plates are reduced, with the first to fourth plates still connected, while the fifth to eighth plates are completely separated. The reduction and separation of shell plates give rise to its Chinese name “隱板” (hidden plates) chiton. This adaptation allows it to live more flexibly and stretch within coral reef crevices or cavities without being constrained by hard shell plates. It is a nocturnal animal and is more likely to be spotted emerging from crevices to forage at night.


▲Elongated and worm-like body, reaching up to 15 cm in length, with both ends being bluntly rounded. (Image provided by Kaohsiung Wild Bird Society)

The discovery site lies within the visitor traffic control area, further demonstrating the gradual success of Little Liuqiu’s “visitor traffic control” conservation efforts in recent years. Located at the gateway where the South China Sea meets the Taiwan Strait, Little Liuqiu plays an important sentinel role in the northward migration of marine species, highlighting the significance of its marine conservation function.