DNA barcoding detects resurrected taxon Giuris laglaizei (Sauvage 1880) in Sulawesi, Indonesia: Bolano Sau Lake payangka phylogeny, phenotypic characters and implications for Giuris spp. conservation

Abstract

Background: The freshwater ichthyofauna of Wallacea is diverse and understudied. A baseline survey of Bolano Sau Lake in Parigi Moutong District, Central Sulawesi Province, Indonesia in 2019 found an eleotrid goby (local name payangka) with characters conforming to the genus Giuris, long considered monophyletic as G. margaritacea/G. margaritaceus but recently found to comprise at least eight species. This study focused on the molecular (DNA barcoding) identification and phenotypic characters of the payangka. Methods: Payangka samples were collected from August to December 2019 in collaboration with local fishermen, weighed and measured, and preserved in 75% ethanol. Length, weight, sex (n=111) and 17 morphometric characters/six meristic counts (n=42) were recorded. DNA barcoding was performed on a fin clipping preserved in 96% ethanol. Homologous nucleotide sequences were obtained from public (GenBank and BOLD) databases, analysis conducted in MEGA X, and phylogenetic trees edited in the Interactive Tree of Life (iToL). Results: Within the deeply divided Giuris clade, the payangka sequence resolved into a sub-clade identified as Giuris laglaizei (Sauvage 1880), a recently resurrected taxon, based on a sequence provided by Philippe Keith. The length-weight relationship (L = 0.0087∙W3.162) indicated mildly allometric positive growth. Size distribution differed significantly between male and female fish with significantly larger mean size of males (13.56 cm) than females (11.62 cm). The meristic formula was: D VI-I,8 A I,8 P 13 V I,5 C15. Phylogenetic analysis indicated four Giuris species in wetlands around Tomini Bay and five in Sulawesi. Conclusions: This first record of G. laglaizei in Indonesia advances knowledge of Wallacean and Indo-Pacific Gobiiformes biogeography and highlights the need for a revision of the conservation status of the taxa currently grouped under Giuris margaritacea/G. margaritaceus in the IUCN Red List and FishBase databases. The data will inform biodiversity and fisheries management at local and regional levels.

Barcoding a glass eel migration: a snapshot of taxa migrating upstream in the Palu River, Central Sulawesi, Indonesia

“…The results confirm the usefulness of DNA barcoding approaches for this region, as described by [52]. However, they also highlight a need to improve the comprehensiveness and reliability of public nucleotide sequence databases, in particular the NCBI GenBank, as noted by other studies in the Wallacea region specifically, and Indonesia or the Indo-pacific region more generally [24,25,35,37], including with respect to diadromous taxa. Addressing these challenges calls for combined morphological and molecular taxonomic work to build the databases on a sound foundation [24], and enable cross-checking when taxonomic nomenclature revisions occur.…”

“…The advances over recent decades in molecular biology include the development of DNA barcoding techniques, enabling identification of a specimen from the nucleotide sequence of a molecular marker; this is a specified region of the genome (barcode) which is highly conserved within a given taxon (ideally species) but differs between taxa [23,24]. This method is increasingly used for identifying specimens that are challenging or impossible to identify based on morphology, such as cryptic species and larval or juvenile stages [18][19][20][21][22]25], including anguillid glass eels [15]. The main limitation of DNA barcoding is that identification depends on the availability of a reference sequence for the taxon being identified in the public nucleotide sequence databases [24].…”

Genetic and morphological analysis of complex Giuris group species from Limboto Lake, Gorontalo Province, Indonesia

“…The allometric growth pattern is temporary due to changes related to gonadal maturity, while the isometric growth pattern is a proportional change that occurs continuously (Phan et al 2021). In the study of the relationship between length and weight, G. margaritaceus from Lake Bolano Sau had a positive allometric growth pattern (Ndobe et al 2023). Likewise, the research by G. margaritaceus from Lake Tondano has a positive allometric growth pattern, which means the growth rate in body weight is faster than in length (Makmur et al 2019).…”

“…The relationship between length and weight in fish is allometric and isometric. Isometric growth is defined as the increase in the length of the fish along with the increase in body weight, while allometric growth is the increase in length faster or slower than the increase in body weight (Ndobe et al 2023).…”

“…The known distribution of species from the genus Giuris in Indonesia is G. aporocephalus, G. laglaizei, G. margaritaceus, G. tolsoni, and G. viator, the five species have minor morphological differences. Furthermore, all of these species are reported in Sulawesi, making the identification of Giuris morphologically and genetically a critical effort to carry out a diversity inventory (Ndobe et al 2023). This study aimed to identify the genus Giuris, especially G. margaritaceus, in Lake Limboto using morphological and genetic approaches to obtain valid data for conservation.…”