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Luciola singapura Jusoh & Ballantyne in Jusoh, Ballantyne, Chan, et al., 2021. DOI: 10.3390/ani11030687 |
Abstract
The firefly genus Luciola sensu McDermott contains 282 species that are distributed across major parts of Asia, Europe, Africa, Australia, and the Pacific islands. Due to phenotypic similarities, species identification using external morphological characters can be unreliable for this group. Consequently, decades of piecemeal taxonomic treatments have resulted in numerous erroneous and contentious classifications. Furthermore, our understanding of the group’s evolutionary history is limited due to the lack of a robust phylogenetic framework that has also impeded efforts to stabilize its taxonomy. Here, we constructed molecular phylogenies of Luciola and its allies based on combined mitogenomes and Cytochrome c oxidase subunit 1 (COX1) sequences including a newly sequenced mitogenome of an unidentified taxon from Singapore. Our results showed that this taxon represents a distinct and hitherto undescribed evolutionary lineage that forms a clade with L. filiformis from Japan and L. curtithorax from China. Additionally, the Singaporean lineage can be differentiated from other congeners through several external and internal diagnostic morphological characters, and is thus described herein as a new species. Our phylogeny also strongly supported the paraphyly of Luciola with regard to L. cruciata and L. owadai, which were inferred to be more closely related to the genus Aquatica as opposed to other members of Luciola sensu stricto. The genus Hotaria was inferred as a derived clade within Luciola (sister to L. italica), supporting its status as a subgenus of Luciola instead of a distinct genus. This is the first time since 1909 that a new species of luminous firefly has been discovered in Singapore, highlighting the need for continued biodiversity research, even in small, well-studied and highly developed countries, such as Singapore.
Keywords: Hotaria; Luciola cruciata; Luciola owadai; Nee Soon Swamp Forest; taxonomy; phylogenetics; conservation
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| Map of Singapore showing the location of Luciola singapura Jusoh & Ballantyne sp. nov. in the Nee Soon Swamp Forest (NSSF) (inset). Numbered dots represent type localities of Luciola species in Asia and the Pacific islands that were examined and/or analysed in this study. |
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| Males of Luciola singapura sp. nov. Habitus (A, B), head and pronotum (C); Tergite 8 after dissection (D). A. Holotype male, from recent collection preserved in ethanol, light organ (LO) located on ventrite 6 (V6) and ventrite 7 (V7), presence of fat body along apex of suture, arrowed; (B). Habitus of paratype male. Coloration of paratype male collected 30 years ago preserved as dry specimen, arrow indicated presence of fat body along suture, tergite 8 (T8) from dorsal view and pronotum (inset); (C). Top: Head and pronotum of paratype male, below: Mouthpart and some parts of antenna; (D). Dissection parts of holotype male: tergites 7‐8 indicated with aedeagus and aedeagal sheath. |
Luciola singapura Jusoh and Ballantyne sp. nov.
English name: Singapore firefly
Malay name: Kunang‐kunang Singapura
Diagnosis: A small species (less than 5 mm long) with distinctive dorsal coloration of black head,
orange to yellowish brown with dark markings on pronotum, and orange to yellowish brown
elytra which have diffuse darker brown to black markings towards the apex, with paler basal
markings restricted to basal area near suture and an accumulation of whitish fat body along
apex of suture and round elytral apex. Metasternum with median dark marking.
Etymology: The specific epithet, singapura, is the Malay name for the country Singapore, which is
the type locality of the new species.
Distribution: Known only from the type locality of NSSF, Central Catchment Nature Reserve in
Singapore but may also occur in other parts of the island
where habitat is suitable.
Conclusions:
The discovery of a new species of firefly from the last remaining freshwater swamp
forest in Singapore—one of the most developed and urbanized countries in the world—
highlights the importance of continued biodiversity research in the region. This study also
underscores the utility of molecular approaches to resolve taxonomic problems and better
understand the evolutionary history of fireflies.
Wan F. A. Jusoh, Lesley Ballantyne, Su Hooi Chan, Tuan Wah Wong, Darren Yeo, B. Nada and Kin Onn Chan. 2021. Molecular Systematics of the Firefly Genus Luciola (Coleoptera: Lampyridae: Luciolinae) with the Description of a New Species from Singapore. Animals. 11(3), 687. DOI: 10.3390/ani11030687
Researchers from the Lee Kong Chian Natural History Museum, National University of Singapore, have discovered a new species of firefly from the last remaining freshwater swamp forest in Singapore. This is the first time since 1909 that a new species of luminous firefly has been discovered in Singapore—highlighting the need for continued biodiversity research, even in small, well-studied, and highly developed countries such as Singapore.
Simple Summary: Fireflies have a scattered distribution in Singapore but are not as uncommon as many would generally assume. A nationwide survey of fireflies in 2009 across Singapore documented 11 species, including “Luciola sp. 2”, which is particularly noteworthy because the specimens were collected from a freshwater swamp forest in the central catchment area of Singapore and did not fit the descriptions of any known Luciola species. Ten years later, we revisited the same locality to collect new specimens and genetic material of Luciola sp. 2. Subsequently, the mitochondrial genome of that population was sequenced and specimens were subjected to rigorous morphological examinations. We then collated published mitogenomes and shorter mitochondrial markers from closely related taxa to infer a phylogeny for the subfamily Luciolinae. Our results reveal that Luciola sp. 2 is both genetically and morphologically distinct from other congeners and is thus described herein as a new species Luciola singapura sp. nov. This marks the first time since 1909 that a new species of luminous firefly has been discovered in Singapore, highlighting the need for continued biodiversity research, even in small, well-studied and highly developed countries such as Singapore that can still harbor undescribed biodiversity.
