Scientists have described a new species of the jellyfish genus Tripedalia from an intertidal shrimp pond in the Mai Po Nature Reserve, Hong Kong.
Morphological characteristics and phylogenetic position of Tripedalia maipoensis. Image credit: Sun et al., doi: 10.6620/ZS.2023.62-17.
The newly-described species represents the fourth described species of the family Tripedaliidae.
Named Tripedalia maipoensis, this jellyfish is also the first record of this family in Chinese coastal waters.
“The class Cubozoa, commonly known as box jellyfish due to the cube-shaped bells, consists of a small group of cnidarians with approximately 50 described species and is well-known to the public for containing some of the most venomous marine animals in the world,” said Hong Kong Baptist University researcher Yanan Sun and colleagues.
“Cubozoa is divided into two monophyletic orders, the Carybdeida and Chirodropida.”
“The two orders can be easily distinguished, as carybdeids possess only one tentacle per pedalium, whereas chirodropids possess multiple tentacles per pedalium.”
“Tripedaliidae is a small family of Carybdeida, with only three described species in two genera: Copula and Tripedalia,” they added.
“Tripedalia possesses two to three pedalia per bell corner, which differs from Copula, which has one pedalium per bell corner.”
“Before our study, Tripedalia was represented by only two species: Tripedalia binata, which has two pedalia at each bell corner, and Tripedalia cystophora, which has three pedalia at each bell corner.”
Both Tripedalia maipoensis and Tripedalia cystophora can be easily distinguished from Tripedalia binata, which bears two pedalia per bell corner.
The new species differs from Tripedalia cystophora by having forked velarial canals, which are unforked in Tripedalia cystophora.
Tripedalia maipoensis is currently known only from the type locality, but may also occur in the adjacent waters of the Pearl River Estuary as the ponds are connected to the estuary through a tidal channel.
The new species was found every year since 2020 in some of the brackish water intertidal shrimp ponds of Mai Po Nature Reserve during April and May, and also extending to June in 2021 when water temperature ranged from 20 to 29 degrees Celsius, and salinity from 5.8 psu to 18 psu.
Tripedalia maipoensis was recorded in water channels flanked by the common reed (Phragmites australis) or mangroves of mainly Kandelia obovata mixed with the golden leather fern (Acrostichum aureum).
“Future investigations along Chinese coasts are warranted to improve our understanding of the distribution of this new species and the diversity of Cubozoa,” the authors said.
The team’s paper was published in the journal Zoological Studies.
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Y. Sun et al. 2023. A new species of box jellyfish (Cnidaria: Tripedaliidae: Tripedalia) from Hong Kong, China. Zool Stud 62: 17; doi: 10.6620/ZS.2023.62-17
